EXHIBIT 2.1

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                              INVASION ENERGY INC.

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                            SHARE PURCHASE AGREEMENT

                                  May 4, 2001




      BLAKE, CASSELS & GRAYDON LLP                      BENNETT JONES LLP
         3500 Bankers Hall East                      4500 Bankers Hall East
         855 - 2nd Street S.W.                        855 - 2nd Street S.W.
        Calgary, Alberta T2P 4J8                    Calgary, Alberta T2P 4K7


                            SHARE PURCHASE AGREEMENT
                            ------------------------



     THIS SHARE PURCHASE AGREEMENT is made as of this 4th day of May 2001.

BETWEEN:

          ENRON CANADA CORP., a corporation existing under the laws of the
          Province of Alberta ("Enron")

                                     -and-

          SKYBIRD ENERGY INC., a corporation existing under the laws of the
          Province of Alberta ("Skybird")

                                    - and -

          The Other Shareholders of Invasion Energy Inc. (other than Enron and
          Skybird), as set forth in Schedules 1.2(b) and 1.2(c) who become party
          hereto (collectively, the "Invasion Minority Shareholders")

          (Enron, in its capacity as a shareholder of Invasion, and the Invasion
          Minority Shareholders are collectively, the "Invasion Vendors" and
          individually, an "Invasion Vendor")

                                    - and -

          EVOLVE MANAGEMENT INC., a corporation existing under the laws of the
          Province of Alberta (the "Manager")

                                     -and-

          JAMES E. PAULSON, an individual resident in the City of Calgary in the
          Province of Alberta ("Paulson")

                                     -and-

          MICHAEL KANOVSKY, an individual resident in the City of Victoria in
          the Province of British Columbia ("Kanovsky")

                                     -and-

          YELLOWBIRD PRODUCTS LIMITED, a corporation existing under the laws of
          the Province of Alberta ("Yellowbird")

                                     -and-


                                      -2-



          C2SKY INC., a corporation existing under the laws of the Province of
          Alberta ("C2Sky")

                                     -and-

          The Other Shareholders of Skybird Energy Inc. (other than C2Sky and
          Yellowbird but including, for certainty, Paulson and Kanovsky) as set
          forth in Schedule 1.2(d) who become party hereto (collectively, the
          "Skybird Minority Shareholders")

          (Yellowbird, C2Sky and the Skybird Minority Shareholders are
          collectively, the "Skybird Vendors" and individually, a "Skybird
          Vendor")

                                     -and-

          THE WISER OIL COMPANY OF CANADA, a corporation existing under the laws
          of the Province of Nova Scotia (the "Purchaser")

                                    - and -

          THE WISER OIL COMPANY, a corporation existing under the laws of the
          State of Delaware ("Wiser")


WHEREAS:

A.   Skybird and Enron are the Requisite Shareholders of Invasion pursuant to
     the terms of the Invasion Shareholder Agreement.

B.   The Total Invasion Shares are currently owned by the Invasion Vendors and
     Skybird.

C.   The Invasion Vendors desire to sell and the Purchaser desires to purchase
     all of the Invasion Shares, upon and subject to the terms and conditions
     set forth in this Agreement.

D.   Paulson and Kanovsky are the Majority Shareholders of Skybird pursuant to
     the terms of the Skybird Shareholder Agreement.

E.   The Skybird Shares are currently owned by the Skybird Vendors.

F.   The Skybird Vendors desire to sell and the Purchaser desires to purchase
     all of the Skybird Shares, upon and subject to the terms and conditions set
     forth in this Agreement.

G.   The Skybird Invasion Shares will be purchased by the Purchaser indirectly
     through the purchase of the Skybird Shares from the Skybird Vendors.

H.   The Enron Royalty and the Enron Debt are currently owned by Enron.


                                      -3-

I.   Enron desires to sell and the Purchaser desires to purchase the Enron Debt,
     upon and subject to the terms and conditions set forth in this Agreement.

     NOW THEREFORE, for good and valuable consideration (the sufficiency and
receipt of which is acknowledged by each Party), the Parties agree as follows:

                                   ARTICLE 1
                           DEFINITIONS AND SCHEDULES

1.1  Definitions
     -----------
     In this Agreement, including the recitals and the Schedules, unless
     otherwise stated or the context otherwise requires:

     "Abandonment and Reclamation Obligations" means all remediation and
     reclamation obligations of Invasion, including:

     (a)  the proper abandonment and reclamation of any Wells; and

     (b)  the closure, decommissioning and dismantling of Tangibles, and the
          restoration of the surface in respect thereto, all in accordance with
          good oil and gas field practices and in compliance with Applicable
          Law.

     "Accounting Firm" means KPMG, Chartered Accountants, or such other firm of
     chartered accountants as may be selected by the Parties.

     "Act" means the Income Tax Act (Canada).

     "Additional Indemnitees" has the meaning set forth in Section 8.1.

     "Adjusted Working Capital" means the amount of the Current Assets of
     Invasion, as recorded on the Effective Date Balance Sheet, less the
     aggregate, without duplication, of (i) the amount of the Current
     Liabilities of Invasion, as recorded on the Effective Date Balance Sheet,
     plus (ii) the book value of the debt or other liabilities of Invasion
     (other than the Enron Debt), recorded as a "liability" on the Effective
     Date Balance Sheet; provided however that (A) all revenues, expenses and
     costs prior to the Effective Date will be accrued in accordance with GAAP
     as if received or paid, as the case may be, prior to the Effective Date;
     (B) the Adjusted Working Capital shall be reduced by any amount payable by
     Invasion to the Manager or any advisor in respect of the transactions
     contemplated by this Agreement, if such obligations are not accrued and
     included in the Effective Date Balance Sheet as at the Effective Date; (C)
     for the purposes of this calculation, no amount shall be included in
     Current Liabilities for any income taxes payable by Invasion; and (D) the
     Adjusted Working Capital shall be reduced by $100,000 if the conditions set
     forth in Section 6.1(j) or 6.1(k) are not satisfied as of the Closing Date,
     which amount shall be refunded to the Vendors, after deduction therefrom of
     all costs and expenses, including reasonable fees and disbursements of
     legal counsel, consultants and advisors and other reasonable out-of-pocket
     expenses, incurred by


                                      -4-


     Invasion and the Purchaser to acquire the balance of the Invasion Shares
     and/or Skybird Shares. Notwithstanding GAAP, the calculation of Current
     Liabilities and debt or other liabilities pursuant to (i) and (ii) above
     specifically excludes any accounting provisions made with respect to GAAP,
     including but not limited to site restoration, future taxes and any other
     similar non-cash items.

     "Affiliate" means, in respect of a Person, any other Person or group of
     Persons acting in concert, directly or indirectly, that controls, is
     controlled by or under common control with the first mentioned Person, and
     for the purposes of this definition "control" means the possession,
     directly or indirectly, by such Person or group of Persons acting in
     concert, of the power to direct or cause the direction of the management
     and policies of the first mentioned Person, whether through the ownership
     of voting securities or otherwise.

     "Agreement" means this Share Purchase Agreement, together with the
     Schedules attached hereto, all as amended, supplemented or modified from
     time to time in accordance with the provisions hereof.

     "Applicable Law" means, in relation to any Person, transaction or event,
     all applicable provisions of laws, statutes, rules, regulations, official
     directives and orders of all federal, provincial, municipal and local
     governmental bodies (whether administrative, legislative, executive or
     otherwise) and judgments, orders and decrees of all courts, arbitrators,
     commissions or bodies exercising similar functions in actions or
     proceedings in which the Person in question is a party, by which it is
     bound or having application to the transaction or event in question.

     "Arbitrator" has the meaning set forth in Section 2.3(h).

     "Burdens" means, collectively, Royalty Interests and Security Interests.

     "Business Day" means a day on which banks are generally open for the
     transaction of commercial business in Calgary, Alberta but does not in any
     event include a Saturday or a Sunday or a bank holiday under Applicable
     Law.

     "Certificate" means a written certification of a matter or matters of fact
     which, if required from a corporation, shall be made by an officer of the
     corporation, on behalf of the corporation and not in any personal capacity.

     "Closing" means the completion of the purchase and sale of the Purchased
     Shares as contemplated by this Agreement.

     "Closing Date" means 10:00 a.m. (Calgary Time) on a Business Day mutually
     agreeable to the Parties no later than May 25, 2001 or such other date as
     is mutually agreed among the Parties.

     "Compliance Certificate" has the meaning set forth in Section 2.6.


                                      -5-

     "Confidentiality Agreement" means the Confidentiality Agreement dated
     February 27, 2001 between Wiser and Invasion.

     "Current Assets" means the book value of the current assets of Invasion as
     of the Effective Date determined in accordance with GAAP.

     "Current Liabilities" means the book value of the current liabilities of
     Invasion, other than the current portion of the Enron Debt as of the
     Effective Date determined in accordance with GAAP.

     "Deposit" means $5,000,000.

     "Dollar" or "$" means, unless otherwise provided herein, a dollar in the
     lawful money of Canada.

     "Effective Date" means 8:00 a.m. on April 30, 2001.

     "Effective Date Balance Sheet" means the unaudited balance sheet of
     Invasion as at the Effective Date, prepared in accordance with GAAP,
     attached hereto as Schedule 1.2(e).

     "Election Time" has the meaning set forth in Section 4.5(b).

     "Encumbrance Discharge" means, with respect to a Security Interest
     affecting all or any portion of the PNG Assets, the Purchased Shares or the
     Skybird Invasion Shares, one or more registrable discharges executed by the
     holder of the Security Interest which results in a discharge of such
     Security Interest; provided that to the extent of any Security Interest
     affecting all or a portion of the PNG Assets, the Purchased Shares or the
     Skybird Invasion Shares, a letter of no interest executed by the holder of
     the Security Interest wherein the holder acknowledges it has no interest in
     the PNG Assets, the Purchased Shares or the Skybird Invasion Shares shall
     be deemed to be an Encumbrance Discharge.

     "Enron Debt" means the aggregate indebtedness of Invasion to Enron, in the
     amount of $23,000,000, plus  4.81% of the Purchase Price, as calculated at
     the Closing Date, being the amount to be paid by Invasion to terminate the
     Enron Royalty pursuant to the terms hereof immediately prior to Closing.

     "Enron Royalty" means the overriding royalty payable by Invasion to Enron
     pursuant to the Royalty Agreement.

     "Environmental Damage" means any one or more of:

     (i)   ground water, surface water or aquifer contamination;

     (ii)  soil contamination;

     (iii) corrosion or deterioration of Tangibles;

     (iv)  substance or energy emissions which are either toxic or hazardous;
           and


                                      -6-

     (v)   death or injury to plant, animals or human beings due in whole or in
           part to any of the foregoing items (i) through (iv);

     but only to the extent the foregoing is or has been in breach of or exceeds
     limitations imposed by Environmental Law and shall not include Abandonment
     and Reclamation Obligations.

     "Environmental Law" means Applicable Law respecting the protection of, or
     the control of contamination or pollution of, soil, air or water (including
     ground water).

     "Financial Statements" means collectively, (i) the audited balance sheet of
     Invasion as at August 31, 2000 and related income statements and statements
     of changes in financial position for the fiscal year then ended, and (ii)
     the Effective Date Balance Sheet and related income statements and
     statements of cashflow of Invasion for the 8 months then ended, copies of
     which are attached as Schedule 1.2(f).

     "Futures Transaction" means any derivatives transaction (including an
     agreement with respect thereto) which is commonly referred to as a hedge
     transaction, rate swap transaction, basis swap, forward rate transaction,
     commodity swap, commodity option, equity or equity index swap, equity or
     equity index option, bond option, interest rate option, foreign exchange
     transaction, cap transaction, floor transaction, collar transaction,
     currency swap transaction, cross-currency rate swap transaction, currency
     option or any other similar transaction (including any option with respect
     to any of these transactions) or any combination of these transactions.

     "GAAP" or "generally accepted accounting principles" means accounting
     principles generally accepted at the relevant time in Canada, and where the
     "CICA Handbook", as amended from time to time, or any successor publication
     published by the Canadian Institute of Chartered Accountants, contains (i)
     a single recommendation as to treatment of a matter, such recommendation
     shall constitute GAAP and generally accepted accounting principles herein,
     or (ii) more than one recommendation as to treatment of a matter, any of
     such recommendations shall constitute GAAP and generally accepted
     accounting principles herein.

     "include" and "including" mean "include, without limitation" and
     "including, without limitation", respectively.

     "Indemnified Losses" has the meaning set forth in Section 8.1.

     "Interim Period" means the period between the Effective Date and the
     Closing Date.

     "Invasion" means Invasion Energy Inc., a corporation existing under the
     laws of the Province of Alberta.

     "Invasion B Shares" means all of the issued and outstanding Class B Common
     Shares of Invasion except the Skybird Invasion Shares.


                                      -7-

     "Invasion C Shares" means all of the issued and outstanding Class C Common
     Shares of Invasion.

     "Invasion Shareholder Agreement" means the Voting and Shareholders
     Agreement dated September 21, 1999 among Enron, Skybird, Invasion and the
     Invasion Minority Shareholders, as amended May 4, 2001.

     "Invasion Shares" means collectively, the Invasion B Shares and the
     Invasion C Shares.

     "Inventory Price Adjustment" has the meaning provided in Section 2.3(b).

     "Land Schedule" means Schedule 1.2(a), as amended by the Parties at anytime
     prior to Closing.

     "Lands" means the lands set forth and described in the Land Schedule
     including the Petroleum Substances within, upon or under the lands (subject
     to the restrictions and exclusions set forth in the Leases as to the
     Petroleum Substances and geological formations), but does not include
     Surface Rights.

     "Leases" means the leases, licences, permits and other documents of title,
     by virtue of which the holder thereof is entitled to drill for, win, take,
     store, own or remove the Petroleum Substances or dispose of saltwater brine
     within, upon or under the Lands or by virtue of which the holder thereof is
     deemed to be entitled to a share of Petroleum Substances removed from the
     Lands or any lands with which the Lands are pooled or unitized and
     includes, if applicable, all renewals and extensions of such documents and
     all documents issued in substitution therefor.

     "Letter Agreement" means the letter agreement dated April 18, 2001 among
     Enron, Skybird, Invasion and Wiser, as amended.

     "Majority Shareholders" means Kanovsky and Paulson.

     "Management Agreement" means the Management Agreement dated September 21,
     1999 pursuant to which the Manager provides to Invasion management and
     operational services as specified therein.

     "Miscellaneous Interests" means all of the right, title, interest and
     estate of Invasion in and to all property, rights and assets, whether
     contingent or absolute, legal or beneficial, present or future, vested or
     not, and not being Petroleum and Natural Gas Rights or Tangibles, which
     pertain to such Petroleum and Natural Gas Rights or Tangibles, including
     the following property, rights and assets:

     (i)    contracts, agreements and documents (including Title and Operating
            Documents) relating to any of such Petroleum and Natural Gas Rights
            or Tangibles or any rights in relation thereto;

     (ii)   Surface Rights which are used or useful in connection with any of
            such Petroleum and Natural Gas Rights or Tangibles;


                                      -8-

     (iii)  permits, licences, authorizations and deposits relating to any of
            such Petroleum and Natural Gas Rights or Tangibles, or the use
            thereof;

     (iv)   all well bores located on the Lands or lands pooled or unitized
            therewith which may be used to produce Petroleum Substances from the
            Lands or lands pooled or unitized therewith or otherwise serve such
            lands;

     (v)    books, maps, records, documents, seismic, geological, data
            processing, well, plant and other reports, files, data, information,
            tapes, disks, computer programs, papers or other records, which
            relate to or are necessary or useful in connection with any of such
            Petroleum and Natural Gas Rights or Tangibles or any of the property
            or assets referred to in (i) to (iv) of this definition; and

     (vi)   all extensions, renewals, replacements or amendments of the
            foregoing items described in items (i) to (v) of this definition.

     "Notice of Claim" has the meaning attributed to it in Section 8.1.

     "Objection Date" has the meaning provided in Section 2.3(f).

     "Parties" means the parties to this Agreement and "Party" means any one of
     them.

     "Permitted Defects" means:

     (i)    Permitted Encumbrances;

     (ii)   Abandonment and Reclamation Obligations which under Applicable Law,
            as of the Closing Date, are not yet required to be undertaken; and

     (iii)  any defects which are deemed to be Permitted Defects under Section
            4.5(e).

     "Permitted Encumbrances" means:

     (i)    easements, rights of way, servitudes or other similar Surface
            Rights, including rights of way and servitudes for highways,
            railways, sewers, drains, gas and oil pipelines, gas and water
            mains, electric light, power, telephone or cable television
            conduits, poles, wires or cables, which do not materially interfere
            with Invasion's use or enjoyment of the PNG Assets;

     (ii)   the right reserved to or vested in any government, municipality or
            other public authority by the term of any Title and Operating
            Documents or by Applicable Law to terminate any Title and Operating
            Documents or to require annual or other periodic payments as a
            condition of the continuance thereof;

     (iii)  rights of general application reserved to or vested in any
            governmental authority to levy taxes or other levies on Petroleum
            Substances or the income or revenue therefrom and governmental
            requirements pertaining to production rates from


                                      -9-


            wells on the Lands or operations being conducted on the Lands or
            otherwise affecting the value of any property;

     (iv)   any rights reserved to or vested in any municipality or
            governmental, statutory or public authority to control or regulate
            any of the PNG Assets in any manner;

     (v)    the terms and conditions of the Title and Operating Documents;

     (vi)   undetermined or inchoate liens incurred or created in the ordinary
            course of business as security in favour of any Person for the
            Invasion's proportionate share of the costs and expenses applicable
            to the development or operation of any of the PNG Assets which are
            not due or delinquent or are being contested in good faith;

     (vii)  the reservations, limitations, provisos and conditions in any grants
            or transfers from the Crown of any of the Lands or interests
            therein, and statutory exceptions to title;

     (viii) provisions for penalties and forfeitures under agreements as a
            consequence of non-participation in operations;

     (ix)   liens granted in the ordinary course of business to a public
            utility, municipality or governmental authority with respect to
            operations pertaining to any of the PNG Assets;

     (x)    any preferential rights of purchase or any similar restriction
            applicable to any of the PNG Assets;

     (xi)   builder's, mechanic's, material men's and similar liens in respect
            of services rendered or goods supplied for which payment is not at
            the time due;

     (xii)  the Burdens, reduction or conversion or alteration of interests and
            adverse claims, in each case, set forth in the Land Schedule (other
            than the Enron Royalty) and all ad valorem, property, production,
            severance and similar taxes and assessments based on or measured by
            the ownership of Petroleum and Natural Gas Rights or the production
            of Petroleum Substances in respect of such Petroleum and Natural Gas
            Rights, whether or not set forth on the Land Schedule;

     (xiii) Burdens that have not been created by, through or under Invasion and
            of which the Vendors do not have any knowledge on the Closing Date;
            and

     (xiv)  Burdens arising from the Enron Debt and, prior to Closing, the Enron
            Royalty.

     "Person" includes an individual, a partnership, a corporation, a trust, a
     joint venture, an unincorporated organization, a union, a government or any
     department or agency thereof and the heirs, executors, administrators or
     other legal representatives of an individual.

     "Petroleum and Natural Gas Rights" means all of the right, title, estate
     and interest, whether absolute or contingent, legal or beneficial, present
     or future, vested or not, and


                                      -10-


     whether or not an "interest in land", held by Invasion in or to the Lands
     and the Leases together with any of the following which relate thereto, by
     whatever name the same are known:

     (i)    rights to explore for, drill for, extract, win, produce, take, save
            or market Petroleum Substances;

     (ii)   rights to a share of the production of Petroleum Substances;

     (iii)  rights to a share of the proceeds of, or to receive payment
            calculated by reference to, the quantity or value of the production
            of Petroleum Substances, other than the rights under agreements for
            the sale of Petroleum Substances;

     (iv)   the interests set forth in the Land Schedule hereto in and to and in
            respect of the Leases and the Lands subject to the Permitted
            Encumbrances;

     (v)    rights to acquire any of the rights described in subparagraphs (i)
            to (iv) of this definition; and

     (vi)   interests in any rights described in subparagraphs (i) to (v) of
            this definition;

     including all interests and rights known as working interests, royalty
     interests, overriding royalty interests, gross overriding royalty
     interests, production payments, profits interests, net profits interests,
     revenue interests, net revenue interests, economic interests and other
     interest, fractional or undivided interests in any of the foregoing, and
     all freehold, leasehold or other interests in any Lands.

     "Petroleum Substances" means petroleum, crude bitumen, natural gas, natural
     gas liquids, related hydrocarbons and any and all other substances, whether
     liquid, solid or gaseous (other than coal), whether hydrocarbon or not,
     produced or producible in association with any of the foregoing, including
     hydrogen sulphide and sulphur.

     "Place of Closing" means the offices of Bennett Jones LLP located at 4500,
     855 - 2nd Street S.W., Calgary, Alberta, or such other place as may be
     agreed upon in writing by the Parties.

     "PNG Assets" means the Petroleum and Natural Gas Rights, the Tangibles and
     the Miscellaneous Interests.

     "Prime Rate" means the annual rate of interest designated by the main
     branch in Calgary of the Royal Bank of Canada as its reference rate for
     Canadian dollar commercial loans made in Canada and which is announced by
     such bank as its prime rate.

     "Proposal" has the meaning set forth in Section 4.5.

     "Purchase Agreement Default" means any material misrepresentation or breach
     of warranty made by a Party, or the failure of a Party to perform or
     observe in any material respect any of the material covenants or agreements
     to be performed by such Party under


                                      -11-


     this Agreement or any agreement or other Certificate or instrument
     delivered in connection herewith, and includes the obligations set forth in
     Section 6.3.

     "Purchase Price" has the meaning set forth in Section 2.2(a).

     "Purchased Shares" means the Invasion Shares and the Skybird Shares.

     "Requisite Shareholders" means Enron and Skybird.

     "Resource Pools" means the:

     (a)  cumulative Canadian exploration expense;

     (b)  cumulative Canadian development expense; and

     (c)  cumulative Canadian oil and gas property expense;
          as such terms are defined in the Act, of Invasion.

     "Royalty Agreement" means the Royalty Agreement dated September 21, 1999
     between Invasion and Enron.

     "Royalty Interests" means all carried profits, net profits, net revenue,
     royalty interests (including ad valorem, property, production, severance
     and similar taxes and assessments based on or measured by the ownership of
     Petroleum and Natural Gas Rights or the production of Petroleum Substances
     in respect of such Petroleum and Natural Gas Rights) and similar Petroleum
     and Natural Gas Rights reserved or payable (by way of a share in production
     of Petroleum Substances or by way of money) to any Person or entity.

     "Security Interest" means any mortgage, charge, pledge, lien, hypothec,
     assignment by way of or in effect as security, or security interest
     whatsoever, but does not include a right of set-off or a set-off.

     "Share Consideration" shall have the meaning set forth in Section
     2.2(a)(i).

     "Share Rights" means any instruments or contractual rights capable of being
     converted into, exchanged for or exercised for Shares of any class of a
     Person or giving the holder the right on the occurrence of any events,
     including on the payment of money, whether such events have occurred or
     not, to require delivery by a Person of Shares of any class of a Person and
     includes options, warrants, conversion or exchange privileges and similar
     rights.

     "Shareholder Debt" means any indebtedness owed by Invasion to the Invasion
     Vendors or Skybird, or any Affiliate of the Invasion Vendors or Skybird.

     "Shares" means any shares of any class of a corporation or body corporate.


                                      -12-

     "Siren" means Siren Capital Corp., a non-resident shareholder of part of
     the Invasion B Shares.

     "Skybird Common Shares" means all of the issued and outstanding common
     Shares of Skybird.

     "Skybird Financial Statements" means the unaudited balance sheet as at
     April 30, 2001 and the profit and loss statement for the period September
     2000 to April 2001 of Skybird, copies of which are attached hereto as
     Schedule 1.2(g).

     "Skybird Invasion Shares" means the 4,102,504 Class B Shares of Invasion
     owned by Skybird.

     "Skybird Preferred Shares" means all of the issued and outstanding
     preferred Shares of Skybird.

     "Skybird Shareholder Agreements" means the Unanimous Shareholder Agreement
     dated November 23, 1999 among Skybird and its shareholders.

     "Skybird Shares" means collectively, the Skybird Common Shares and the
     Skybird Preferred Shares.

     "Subsidiary" when used in relation to any Person, means any Affiliate
     controlled, directly or indirectly, by that Person.

     "Surface Rights" means rights (whether fee simple or pursuant to orders,
     licences, leases, easements, rights-of-way or otherwise) to enter upon, use
     and occupy the surface of any Lands, any lands with which the same have
     been pooled or unitized or any lands upon which the Tangibles are located.

     "Survival Period" means the period ending 6 months after Closing.

     "Take or Pay Delivery Obligations" means the obligation of Invasion arising
     under or pursuant to any contract whereby Petroleum Substances attributable
     to the Petroleum and Natural Gas Rights or any of them may be sold for or
     in respect of payments or credits previously received by Invasion, its
     predecessors or others in respect of Petroleum Substances, the delivery of
     which had not been taken by the buyer thereof at the time of the payment or
     crediting, whether or not:

     (i)    Invasion is a party to such contract;

     (ii)   the buyer of such Petroleum Substances recognizes Invasion as a
            seller or has recourse to Invasion; or

     (iii)  the payment, credit or assumption was made to or by Invasion or was
            remitted by Invasion to any other Person.


                                      -13-

     "Take or Pay Payments" means, as at a particular time, the amounts received
     or receivable by and for the account of Invasion prior to such time as a
     result of which Invasion has Take or Pay Delivery Obligations which, as at
     such time, have not been satisfied and have not expired.

     "Tangibles" means all right, title, estate and interest, whether absolute
     or contingent, legal or beneficial, present or future, vested or not, held
     by Invasion in and to any tangible property, apparatus, plant, equipment,
     machinery and facilities, fixed or non-fixed, real or personal, used or
     capable of use in exploiting any Petroleum Substances (whether the
     Petroleum and Natural Gas Rights to which such Petroleum Substances are
     attributable or are owned by Invasion or by others or both), including:

     (i)    systems, plants and facilities used or useful in producing,
            gathering, compressing, dehydrating, scrubbing, processing,
            treating, separating, extracting, collecting, refrigerating,
            refining, measuring, storing, transporting or shipping Petroleum
            Substances;

     (ii)   tangible property and assets used or intended for use in exploring
            for, producing, storing, injecting or removing Petroleum Substances;

     (iii)  all extensions, additions and accretions to any item described in
            subparagraphs (i) and (ii) of this definition; and

     (v)    the Wells;

     and including all producing, shut-in, injection, disposal, abandoned and
     other wells, casing, tubing, wellheads, buildings, plants, erections,
     production equipment, improvements, flowlines, pipelines, pipeline
     connections, extraction facilities, meters, generators, motors,
     compressors, separators, gas treating and processing equipment,
     dehydrators, scrubbers, pumps, refineries, pump jacks, tanks, boilers,
     communications equipment, enhanced recovery systems and other machinery,
     apparatus and equipment.

     "taxes" includes all income, capital, gross receipts, sales, excise,
     petroleum and gas revenue, value added, goods and services, use, franchise,
     profits or property taxes, fees, assessments or charges imposed in
     accordance with Applicable Law and includes penalties, interest and fines
     with respect thereto.

     "Tax Returns" means all returns, declarations and reports and information
     returns and statements required to be filed (taking into account any
     extension of time to file or send granted to or obtained by any such filing
     entity) by Invasion or Skybird, as applicable, under Applicable Law related
     to tax or in respect of any tax, for any period including or ending on or
     before the Closing Date.

     "Title and Operating Documents" means, in respect of any Petroleum and
     Natural Gas Rights, Tangibles, or Surface Rights of Invasion, (i) all of
     the agreements, contracts, instruments and other documents (including the
     Leases and all other leases, reservations, permits, licences of all sorts,
     exploration agreements, operating agreements, unit


                                      -14-

     agreements, pooling agreements, assignments, trust declarations or other
     agreements to recognize Invasion's interests, participation agreements,
     farmin or farmout agreements, royalty agreements, purchase agreements and
     transfers, (A) gas, oil, condensate and other production sale contracts,
     (B) gathering, common stream, extraction, transportation, refining and
     processing agreements, (C) agreements for the construction, ownership
     and/or operation of Tangibles) by virtue of which such Petroleum and
     Natural Gas Rights or Tangibles were acquired or constructed or are held by
     the Invasion or pursuant to which the construction, ownership, operation,
     exploration, exploitation, extraction, development, production,
     transportation, refining or marketing of such Petroleum and Natural Gas
     Rights, Tangibles or Petroleum Substances are subject or which grant rights
     which are or may be used by the Person in connection therewith, and (ii)
     the rights (except for Petroleum and Natural Gas Rights) granted under or
     created by such agreements, contracts, instruments and other documents; but
     only if the foregoing pertain in whole or part to Petroleum Substances
     within, upon or under the Lands.

     "Total Invasion Shares" means the Invasion Shares and the Skybird Invasion
     Shares.

     "Vendors" means collectively the Invasion Vendors and the Skybird Vendors.

     "Vendors' Counsel" means Bennett Jones LLP.

     "Vendors' Representatives" has the meaning set forth in Section 5.7.

     "Wells" means all producing, suspended, shut-in, abandoned, water source
     disposal or injection wells located on the Lands or any lands pooled or
     unitized therewith, including the wells listed in the Land Schedule.

1.2  Schedules
     -----------

     The following Schedules are attached hereto and made part of this
     Agreement:

     (a)  Schedule 1.2(a)  Land Schedule
     (b)  Schedule 1.2(b)  Class B Shareholders of Invasion
     (c)  Schedule 1.2(c)  Class C Shareholders of Invasion
     (d)  Schedule 1.2(d)  Skybird Shareholders
     (e)  Schedule 1.2(e)  Effective Date Balance Sheet
     (f)  Schedule 1.2(f)  Invasion Financial Statements
     (g)  Schedule 1.2(g)  Skybird Financial Statements
     (h)  Schedule 5.1(p)  Disclosure re: Contracts and Commitments

1.3  References and Headings
     -----------------------

     The references "hereunder", "herein" and "hereof" refer to the provisions
     of this Agreement, and references to Article, Sections and Schedules herein
     refer to articles, sections, or schedules of this Agreement.  Any reference
     to time shall refer to Mountain Standard Time or Mountain Daylight Saving
     Time during the respective intervals in


                                      -15-


     which each is in force in the Province of Alberta. The headings of the
     Articles, Sections, Schedules and any other headings, captions or indices
     herein are inserted for convenience of reference only and shall not be used
     in any way in construing or interpreting any provision hereof.

1.4  Singular/Plural; Derivatives
     ----------------------------

     Whenever the singular or masculine or neuter is used in this Agreement or
     in the Schedules, it shall be interpreted as meaning the plural or feminine
     or body politic or corporate, and vice versa, as the context requires.
     Where a term is defined herein, a capitalized derivative of such term shall
     have a corresponding meaning unless the context otherwise requires.

1.5  Statutory References
     --------------------

     Any reference to a statute shall include and shall be deemed to be a
     reference to such statute and to the regulations made pursuant thereto, and
     all amendments made thereto and enforced from time to time, and to any
     statute or regulation that may be passed which has the effect of
     supplementing the statute so referred to or the regulations made pursuant
     thereto.

1.6  Conflicts
     ---------
     If there is any conflict or inconsistency between a provision of the body
     of this Agreement and that of a Schedule, the provision of the body of this
     Agreement shall prevail.

1.7  Accounting References
     ---------------------

     Where the character or amount of any asset or liability or item of income
     or expense is required to be determined, or any consolidation or other
     accounting computation is required to be made for the purposes of this
     Agreement, the same shall be done in accordance with GAAP except where the
     application of such principles is inconsistent with, or limited by, the
     terms of this Agreement.

1.8  Vendor's Knowledge
     ------------------

     Where in this Agreement a representation is made on the basis of the
     knowledge or awareness of the Vendors with respect to the Purchased Shares
     or Enron with respect to the Enron Debt and the Enron Royalty, such
     knowledge or awareness consists only of the actual knowledge or awareness,
     as the case may be, of each of the Vendors or Enron, and does not include
     knowledge and awareness of any other Person or Persons.


                                      -16-

                                   ARTICLE 2
                               PURCHASE AND SALE

2.1  Purchase and Sale
     -----------------
     Upon the terms and subject to the conditions of this Agreement:

     (a)  each Invasion Vendor agrees to sell the Invasion Shares held by it to
          the Purchaser and the Purchaser agrees to purchase the Invasion Shares
          from the Invasion Vendors;

     (b)  each Skybird Vendor agrees to sell the Skybird Shares held by it to
          the Purchaser and the Purchaser agrees to purchase the Skybird Shares
          from the Skybird Vendors;

     (c)  Enron agrees to sell the Enron Debt to the Purchaser and the Purchaser
          agrees to purchase the Enron Debt from Enron; and

     (d)  if the Purchaser does not purchase the Skybird Shares due to the
          application of Section 7.4 and is required to purchase the Skybird
          Invasion Shares, the Purchaser shall buy and Skybird shall sell the
          Skybird Invasion Shares. For greater certainty, if the Purchaser is
          obligated to purchase the Skybird Invasion Shares:

          (i)    the Skybird Invasion Shares shall be included in the definition
                 of Purchased Shares;

          (ii)   Skybird shall be deemed to be an Invasion Vendor for the
                 purposes hereof and shall have all the rights and obligations
                 of an Invasion Vendor, as they relate to the Skybird Invasion
                 Shares; and

          (iii)  for purposes of the allocation of Purchase Price pursuant to
                 Section 2.2(b), the allocation to the Invasion B Shares shall
                 be determined after adjusting Schedule 1.2(b) to include the
                 Skybird Invasion Shares in the allocation and the obligation of
                 the Skybird Vendors pursuant hereto shall terminate.

2.2  Payment of Purchase Price
     -------------------------

     (a)  The Purchaser agrees to pay the Invasion Vendors, the Skybird Vendors
          and Enron, at the Closing, $56,000,000 (the "Purchase Price"),
          allocated as follows:

          (i)    first to the Enron Debt, payable to Enron;

          (ii)   any remainder to the Purchased Shares (the "Share
                 Consideration"), for the Purchased Shares payable to the
                 Vendors, which shall be adjusted in accordance with these
                 Sections 2.2(a) and 2.3:

                 (A)  at Closing, on an interim basis in the manner set forth in
                      Sections 2.3(a), 2.3(b), 2.3(d) and 2.3(e); and


                                      -17-

               (B)  after Closing, in the manner set forth in Section 2.3.

     The Purchaser shall not be obligated to pay the portion of the Share
     Consideration attributable to any Invasion Shares or Skybird Shares which
     are not tendered by the Vendors and shall only be obligated to pay pursuant
     hereto the amounts allocated in accordance with Section 2.2(b) to the
     Vendors who have tendered Purchased Shares at Closing.  For greater
     certainty, any amounts by which the Share Consideration is reduced as a
     result of the failure of a Vendor to tender its Invasion Shares or its
     Skybird Shares at Closing shall be allocated entirely to such Vendor's
     allocation of the Share Consideration and any adjustment thereof pursuant
     to Section 2.3 and shall not, in any way, affect any other Vendor's
     allocation of the Share Consideration.

     (b)  The Share Consideration shall be allocated, subject to Section 2.3, as
          follows:

          (i)    an amount equal to the consideration payable to the Invasion C
                 Shares pursuant to the Invasion Shareholders Agreement, as
                 confirmed by a Certificate of the Requisite Shareholders and
                 the President of Invasion, (the "Class C Consideration"), which
                 shall be allocated to each holder of Invasion C Shares in
                 accordance with Schedule 1.2(c);

          (ii)   68.09% of the aggregate of the Share Consideration less the
                 Class C Consideration, to the aggregate Invasion B Shares which
                 amount shall be allocated to each holder of Invasion B Shares
                 in accordance with Schedule 1.2(b); and

          (iii)  31.91% of the aggregate of the Share Consideration less the
                 Class C Consideration, to the Skybird Shares which amount shall
                 be allocated to each holder of Skybird Shares in accordance
                 with Schedule 1.2(d).

     Any adjustment to the Share Consideration pursuant to Section 2.3 shall be
     made to the above amounts in proportion to their allocation of the total
     Share Consideration as set forth above.

2.3  Adjustments to Portion of Purchase Price Allocated to Invasion Shares
     ---------------------------------------------------------------------

     (a)  Calculation of Working Capital Adjustment at Closing:  The Share
          ----------------------------------------------------
          Consideration shall be increased or decreased on a dollar for dollar
          basis by the amount by which the Adjusted Working Capital is greater
          or less than $1,312,000. If the Adjusted Working Capital:

          (i)    exceeds $1,312,000, then the Share Consideration shall be
                 increased by the amount of such excess; or

          (ii)   is less than $1,312,000, then the Share Consideration shall be
                 reduced by the amount of such shortfall.

     (b)  Calculation of Inventory Price Adjustment at Closing:  The Share
          ----------------------------------------------------
          Consideration shall, without duplicating any adjustments included in
          the calculation of the


                                      -18-


          Adjusted Working Capital, be increased by an amount (the "Inventory
          Price Adjustment") equal to the market value of the Petroleum
          Substances owned by Invasion which are in tanks or storage as at the
          Effective Date. The market value of such Petroleum Substances shall be
          an amount equal to the price for which such Petroleum Substances are
          sold in accordance with applicable marketing agreements less the costs
          of treating the Petroleum Substances and transporting them to the
          point of sale calculated in accordance with applicable marketing
          agreements.

     (c)  Calculation of Adjustment after Closing:  The adjustments to the Share
          ---------------------------------------
          Consideration as provided in Section 2.3(a)and 2.3(b) shall be
          calculated and paid on the Closing Date based on the Effective Date
          Balance Sheet, which is attached as Schedule 1.2(e). Such adjustments
          to the Share Consideration shall be recalculated and paid based on the
          final Effective Date Balance Sheet as contemplated in Section 2.3(j).
          Any amounts payable by the Purchaser or the Vendors, as applicable,
          based on the final Effective Date Balance Sheet shall be adjusted to
          give credit for adjustments paid on the Closing Date pursuant to
          Section 2.3(a) and 2.3(b).

     (d)  Calculation of Interest at Closing:  The portion of the Purchase Price
          ----------------------------------
          attributable to the Enron Debt shall be increased by the amount of
          simple daily interest for the Interim Period at 9.5% on such amount
          and the portion of the Purchase Price attributable to the Share
          Consideration shall be increased by the amount of simple daily
          interest for the Interim Period at the Prime Rate on such amount plus
          or minus (as applicable) the other adjustments made pursuant to this
          Section 2.3.

     (e)  Effective Date Balance Sheet:
          ----------------------------

          (i)    The Effective Date Balance Sheet shall be used by the Vendors
                 and Purchaser for the purposes of initially determining the
                 Adjusted Working Capital as at the Closing Date, subject to the
                 adjustments after the Closing Date in accordance with the
                 remaining provisions of this Section 2.3.

          (ii)   No later than 60 days after the Closing Date, the Purchaser
                 shall prepare and deliver to Enron, Yellowbird and C2Sky the
                 final Effective Date Balance Sheet. The Purchaser shall provide
                 to Enron, Yellowbird and C2Sky the right to review the final
                 Effective Date Balance Sheet and full access to the working
                 papers of the Purchaser to aid in such review.

     (f)  Invasion Vendor's Objections:  If any of Enron, Yellowbird and C2Sky
          ----------------------------
          believes that any change is required to be made to the final Effective
          Date Balance Sheet as prepared by the Purchaser, it shall, on or
          before that date (the "Objection Date") which is 10 Business Days
          after the delivery of the final Effective Date Balance Sheet by the
          Purchaser pursuant to Section 2.3(e)(ii) give written notice of any
          such proposed change, including the reason for such change, to the
          Purchaser. In the event that Enron, Yellowbird or C2Sky do not notify
          the


                                      -19-


          Purchaser of any proposed change on or before the Objection Date,
          then the Vendors shall be deemed to have accepted the final Effective
          Date Balance Sheet.

     (g)  Settlement by Accounting Firm: If any of Enron, Yellowbird and C2Sky
          -----------------------------
          gives written notice of any such proposed change on or before the
          Objection Date, and if the proposed change is disputed by either of
          the Parties and they fail to resolve such dispute within 7 days after
          the Objection Date, then the Accounting Firm shall be engaged
          forthwith to resolve the dispute that cannot be agreed upon and the
          Accounting Firm shall be required to render its decision without
          qualifications, other than the usual qualifications relating to
          engagements of this nature, within 14 days after the dispute is
          referred to it. The decision of the Accounting Firm shall be final and
          binding. The fees and expenses of the Accounting Firm shall be shared,
          one half to the Purchaser and one half to the Vendors on a pro rata
          basis.

     (h)  Settlement by Arbitrator: In the event that the Accounting Firm cannot
          ------------------------
          or will not make a decision in the manner provided above, the
          Purchaser, Enron, Yellowbird and C2Sky shall refer such matter to
          Arthur Andersen LLP (the "Arbitrator") to arbitrate the dispute as a
          single arbitrator in accordance with the Arbitration Act (Alberta)
          within 60 days after the Objection Date. If the Arbitrator cannot or
          will not make a decision with respect to any matter in dispute, the
          Purchaser, Enron, Yellowbird or C2Sky may proceed to the Court of
          Queen's Bench (Calgary) for resolution of the dispute. The decision of
          the Arbitrator with respect to any matter in dispute (including as to
          all procedural matters) shall be final and binding on the Vendors and
          the Purchaser and shall not be subject to appeal by either Party. The
          fees and expenses of the Arbitrator shall be shared, one half to the
          Purchaser and one half to the Vendors on a pro rata basis.

     (i)  Amendments to Effective Date Balance Sheet: Upon agreement with
          ------------------------------------------
          respect to all matters in dispute, or upon a decision of the
          Accounting Firm or the Arbitrator with respect to all matters in
          dispute, such amendments shall be made to the final Effective Date
          Balance Sheet as may be necessary to reflect such agreement or such
          decision, as the case may be. In such event, references in this
          Agreement to the final Effective Date Balance Sheet shall refer to the
          final Effective Date Balance Sheet, as so amended.

     (j)  Final Effective Date Balance Sheet:  Payment of any adjustment in the
          ----------------------------------
          Purchase Price as a result of any change between the Effective Date
          Balance Sheet and the final Effective Date Balance Sheet shall be made
          to the Vendors (in accordance with the allocation of the Share
          Consideration set forth in Section 2.2(b)) or by the Vendors to the
          Purchaser, as the case may be, within 10 Business Days after the
          delivery of the final Effective Date Balance Sheet, pursuant to
          Section 2.3(e)(ii) or 2.3(i), as applicable. Payment of the disputed
          portion or any part thereof, if any, of any adjustment in the Purchase
          Price shall be made to the Vendors (in accordance with the allocation
          of the Share Consideration set forth in Section 2.2(b)) or by Vendors
          to the Purchaser, as the case may be, within 5 Business


                                      -20-


          Days after the disputed portion has been agreed upon by the Parties or
          determined by the Accounting Firm or Arbitrator as provided herein.

2.4  Deposit
     -------

     Concurrent with the execution and delivery of this Agreement, the Purchaser
     shall pay the Deposit to Vendors' Counsel, who shall invest the Deposit in
     an interest bearing trust account until Closing.  In the event Closing does
     not occur, the Deposit and interest earned thereon shall be paid to the
     Party ultimately entitled to the Deposit pursuant to Section 7.3.

2.5  Payment of Purchase Price
     -------------------------

     The Share Consideration shall be paid by the Purchaser to the Vendors'
     Counsel, in trust, to be allocated among the Vendors in accordance with the
     allocation of the Share Consideration set forth in Section 2.2(b), by the
     payment of the Share Consideration, as adjusted, less the Deposit and
     interest earned thereon, and the direction to release the Deposit.  The
     portion of the Purchase Price allocated to the Enron Debt plus interest at
     9.5% in accordance with Section 2.3(d) shall be paid by the Purchaser to
     Enron.

2.6  Withholding Tax
     ---------------

     If Siren is a party hereto, the Purchaser and Siren acknowledge that
     pursuant to Section 116 of the Act, the Purchaser must withhold and remit
     to the Minister of National Revenue 25% of the amount, if any, by which the
     portion of the Share Consideration received by Siren exceeds the
     certificate limit set out in the certificate of compliance (the "Compliance
     Certificate") obtained by Siren for the purposes of Section 116 of the Act
     in respect of the sale of the Invasion Shares by Siren.  If a Compliance
     Certificate is not delivered to the Purchaser by Siren prior to Closing,
     the Purchaser will withhold 25% of the portion of the Share Consideration
     received by Siren hereunder and remit such amount to the Minister of
     National Revenue in accordance with the provisions of the Act.

2.7  Manner of Payment
     -----------------

     Unless otherwise specified, all payments made pursuant hereto shall be made
     by certified cheque, bank draft or wire transfer in immediately available
     funds.

                                   ARTICLE 3
                                    CLOSING

3.1  Place and Closing Date
     ----------------------

     Unless otherwise agreed in writing by the Parties, Closing shall take place
     at the Place of Closing on the Closing Date.


                                      -21-

3.2  Effective Date of Transfer
     --------------------------

     The transfer and assignment of the Purchased Shares to the Purchaser shall
     be effective as of the Effective Date, provided Closing occurs.  However,
     possession of and title to the Purchased Shares shall not pass to the
     Purchaser until Closing.

3.3  Deliveries at Closing
     ---------------------

     (a)  Invasion Vendors' and Enron's Deliveries to Purchaser:
          -----------------------------------------------------

          At Closing, the Invasion Vendors and Enron shall deliver or shall
          cause to be delivered the following to the Purchaser:

          (i)    certificates representing the Invasion Shares, accompanied by
                 stock transfer powers duly executed in blank or duly executed
                 instruments of transfer, executed in either case by the holder
                 of record thereof and any other documents necessary to transfer
                 to the Purchaser title to the Invasion Shares;

          (ii)   original share books, share ledgers and minute books and
                 corporate seals of Invasion;

          (iii)  all books, records, files, reports, data and documents
                 pertaining to Invasion and in the possession or control of
                 Invasion or the Manager, including any related to (A) the PNG
                 Assets described in items (i), (iii), (v) and (vi) of the
                 definition of Miscellaneous Interests, and (B) the Title and
                 Operating Documents;

          (iv)   a certified copy of resolutions of the board of directors of
                 Invasion authorizing the transfer of the Invasion Shares from
                 the Invasion Vendors to the Purchaser as contemplated by this
                 Agreement;

          (v)    a copy of a special resolution of the shareholders of Invasion
                 authorizing (i) the amendment of the Management Agreement, as
                 contemplated herein and (ii) if requested by the Purchaser, the
                 termination of the Shareholder Agreement, as contemplated
                 herein;

          (vi)   resignations or terminations of all directors and officers of
                 Invasion;

          (vii)  a release, (A) from each Invasion Vendor, of Invasion and its
                 directors, officers and employees, of and from any
                 indebtedness, liability or claim of such Invasion Vendor
                 (except pursuant to this Agreement), save and except with
                 respect to Enron, any indebtedness or liability of Invasion for
                 the Enron Debt; and (B) from each director or officer of
                 Invasion, of and from any indebtedness, liability or claim owed
                 by Invasion to such director or officer (except pursuant to
                 this Agreement) by, or claims against, Invasion;


                                      -22-


          (viii) the Certificates and other documents required by Section 6.1;

          (ix)   a receipt from the Vendors' Counsel in trust for the portion of
                 the Share Consideration attributable to the Invasion Shares;

          (x)    a receipt from Enron for the portion of the Purchase Price
                 attributable to the Enron Debt;

          (xi)   if requested by the Purchaser, an agreement effecting the
                 termination of the Shareholder Agreement as at the Closing
                 Date;

          (xii)  an amending agreement effecting the termination of the
                 Management Agreement as at May 31, 2001, without any obligation
                 or liability to Invasion, the Purchaser or its Affiliates for
                 activities of the Manager prior to the Effective Date and
                 releasing Invasion for any obligations owed by it to the
                 Manager prior to the Effective Date;

          (xiii) an assignment agreement transferring the Enron Debt, and all
                 agreements and documents applicable thereto, to the Purchaser
                 and releasing Invasion for any obligations owed by it to Enron
                 in respect of the Enron Debt from and after the Effective Date;

          (xiv)  a release from Enron for any obligations owed to it by Invasion
                 in respect of the Enron Royalty from and after the sale thereof
                 to Invasion in accordance herewith;

          (xv)   copies of the opinions of Vendors' Counsel dated September 21,
                 1999 with respect to the properties purchased by Invasion from
                 Northstar Energy and Giant Grosmount and confirmation Invasion
                 is entitled to rely on such opinions; and

          (xvi)  such other documents reasonably required to be delivered by the
                 Invasion Vendors or Enron at the Closing pursuant to this
                 Agreement.

    (b)   Skybird Vendors' Deliveries to Purchaser:
          ----------------------------------------

          At Closing, the Skybird Vendors shall deliver or shall cause to be
          delivered the following to the Purchaser:

          (i)    certificates representing the Skybird Shares, accompanied by
                 stock transfer powers duly executed in blank or duly executed
                 instruments of transfer, executed in either case by the holder
                 of record thereof and any other documents necessary to transfer
                 to the Purchaser title to the Skybird Shares;

          (ii)   original share books, share ledgers and minute books and
                 corporate seals of Skybird;


                                      -23-

          (iii)  all books, records, files, reports, data and documents
                 pertaining to Skybird and in the possession or control of
                 Skybird;

          (iv)   a certified copy of resolutions of the board of directors of
                 Skybird authorizing the transfer of the Skybird Shares from the
                 Skybird Vendors to the Purchaser as contemplated by this
                 Agreement;

          (v)    a copy of a special resolution of the shareholders of Skybird
                 authorizing, if requested by the Purchaser, the termination of
                 the Skybird Shareholder Agreement, as contemplated herein;

          (vi)   resignations or terminations of all directors and officers of
                 Skybird;

          (vii)  a release from each Skybird Vendor of Skybird and its
                 directors, officers and employees, of and from any
                 indebtedness, liability or claim of such Skybird Vendor;

          (viii) the Certificates and other documents required by Section 6.1;

          (ix)   a receipt from Vendors' Counsel in trust for the portion of the
                 Share Consideration attributable to the Skybird Shares;

          (x)    if requested by the Purchaser, an agreement effecting the
                 termination of the Skybird Shareholder Agreement as at the
                 Closing Date; and

          (xi)   such other documents reasonably required to be delivered by the
                 Skybird Vendors at the Closing pursuant to this Agreement.

    (c)   Purchaser Deliveries to the Vendors and Enron:
          ---------------------------------------------

          At Closing, the Purchaser shall deliver, or cause to be delivered, the
          following to the Vendors and Enron, as applicable:

          (i)    the Purchase Price in accordance with Section 2.5, as adjusted
                 in accordance with Article 2;

          (ii)   a direction to release the Deposit;

          (iii)  the Certificates and other documents required by Section 6.2;

          (iv)   a release of the directors and officers of Invasion, from the
                 Purchaser, of and from any indebtedness, liability or claim
                 owed to Invasion (excluding those pursuant to this Agreement)
                 by, or claims against, the directors and officers of Invasion;
                 and

          (v)    such other documents as may be required to be delivered by the
                 Purchaser at Closing pursuant to this Agreement.


                                      -24-

                                   ARTICLE 4
                                INTERIM PERIOD

4.1  Access
     ------

    (a)   The Requisite Shareholders will cause Invasion directly or indirectly,
          through the activities of the Manager pursuant to the Management
          Agreement, to furnish to the Purchaser and its authorized
          representatives reasonable access during the Interim Period, during
          the normal business hours, at the Purchaser's sole cost, risk and
          expense, to Invasion's properties (including the PNG Assets), books
          and records and will cause Invasion directly or indirectly, through
          the activities of the Manager pursuant to the Management Agreement, to
          furnish to the Purchaser and its authorized representatives such
          additional financial and operating data and other information as it
          may reasonably request to the extent that such access and disclosure
          would not violate the terms of any agreement to which Invasion is
          bound or any Applicable Law.

    (b)   The access afforded to the Purchaser and its representatives pursuant
          to Section 4.1(a) shall include:

          (i)    access to Invasion's records, files, reports, data and
                 documents directly or indirectly relating to the PNG Assets at
                 the offices of Invasion in Calgary, Alberta, during normal
                 business hours, for the purpose of the Purchaser's review of
                 the PNG Assets and the title of Invasion thereto and
                 investigation of the business and condition (financial or
                 otherwise) of Invasion, including:

                 (A)  all operating, technical, financial and environmental data
                      and information, including Invasion's minute books, books
                      of account, tax records and technology; and

                 (B)  the PNG Assets described in items (i), (ii), (iii), (v)
                      and (vi) of the definition of Miscellaneous Interests; and

          (ii)   a reasonable opportunity to conduct a physical inspection of
                 the PNG Assets (including the Wells, Tangibles and surface
                 areas included therein or associated therewith) at the
                 Purchaser's sole cost, risk and expense, insofar as the
                 Invasion Vendors can cause, pursuant to the Title and Operating
                 Documents, any third party to reasonably provide such access to
                 the PNG Assets;

          provided that access to all such information and data described in
          this Section 4.1(b) shall be subject to the restrictions described in
          Section 4.1(a).


                                      -25-

4.2  Maintenance of Business and PNG Assets
     --------------------------------------

     (a)  Except as contemplated herein or as otherwise consented to by the
          Purchaser in writing during the Interim Period (which consent shall
          not be unreasonably withheld), the Requisite Shareholders shall cause
          Invasion directly or indirectly, through the activities of the Manager
          pursuant to the Management Agreement, to use all reasonable efforts
          (having regard to the terms and provisions of the Title and Operating
          Documents and to the nature of Invasion's interest in the PNG Assets)
          to:

          (i)    conduct its activities and operations in the ordinary and usual
                 course of its business;

          (ii)   operate and maintain the PNG Assets in a proper and prudent
                 manner in accordance with generally accepted oil and gas
                 industry practices, the Title and Operating Documents and
                 Applicable Law; and

          (iii)  maintain any insurance in force with respect to the PNG Assets.

    (b)   Except as contemplated herein or as otherwise consented to by the
          Purchaser in writing during the Interim Period, the Majority
          Shareholders shall cause Skybird to conduct its activities and
          operations in the ordinary and usual course of its business.

4.3  Certain Changes Restricted
     --------------------------

     (a)  Without first obtaining the written consent of the Purchaser (which
          consent will not be unreasonably withheld), during the Interim Period,
          the Requisite Shareholders shall ensure that Invasion directly or
          indirectly, through the activities of the Manager pursuant to the
          Management Agreement, will not:

          (i)    amend in any material respect any contract or agreement
                 required to be disclosed pursuant to Section 5.1(p);

          (ii)   declare, set aside or pay any dividends, or make any
                 distributions in respect of the Total Invasion Shares or Share
                 Rights, or repurchase, redeem or otherwise acquire any of the
                 Total Invasion Shares or Share Rights;

          (iii)  make any payments to the Invasion Vendors, Skybird or any
                 Affiliate of the Invasion Vendors or Skybird or any other
                 Person in which the Invasion Vendors, Skybird or any of their
                 Affiliates owns any equity securities or ownership interests
                 (including payments on account of Shareholder Debt);

          (iv)   incur any additional Shareholder Debt;

          (v)    incur, assume or otherwise become liable for any debts or
                 charges to the Invasion Vendors, Skybird or any Affiliate of
                 the Invasion Vendors or


                                      -26-


                 Skybird, other than for bona fide advances or payments made to
                 or for the benefit of Invasion in the ordinary course of
                 business (including continued completion of construction
                 projects already commenced) and consistent with past practice;

          (vi)   amalgamate with, merge into or with or otherwise consolidate
                 with any other corporation or acquire all or substantially all
                 of the business or assets of any Person;

          (vii)  make any change in its constating documents or by-laws;

          (viii) purchase any securities of any Person except short-term
                 investments made in the ordinary course of business;

          (ix)   other than pursuant to existing contracts or commitments
                 existing as of the Effective Date, sell, lease or otherwise
                 dispose of any of its PNG Assets (the extraction and sale of
                 petroleum and natural gas and the consumption or other
                 disposition of its assets and properties in the ordinary course
                 of business being excepted);

          (x)    other than in the ordinary course of business, purchase, lease
                 or otherwise acquire any interest in petroleum or natural gas,
                 real property or real property interests; or

          (xi)   grant a Security Interest, other than a Permitted Encumbrance.

    (b)   Without first obtaining the written consent of the Purchaser, during
          the Interim Period, the Majority Shareholders shall ensure that
          Skybird directly or indirectly, will not:

          (i)    declare, set aside or pay any dividends, or make any
                 distributions in respect of the Skybird Shares or repurchase,
                 redeem or otherwise acquire any of the Skybird Shares;

          (ii)   make any payments to the Skybird Vendors or any Affiliate of
                 the Skybird Vendors or any other Person in which the Skybird
                 Vendors or any of its Affiliates owns any equity securities or
                 ownership interests;

          (iii)  incur any shareholder debt;

          (iv)   incur, assume or otherwise become liable for any debts or
                 charges to the Skybird Vendors or any Affiliate of the Skybird
                 Vendors;

          (v)    amalgamate with, merge into or with or otherwise consolidate
                 with any other corporation or acquire all or substantially all
                 of the business or assets of any Person;

          (vi)   make any change in its constating documents or by-laws;


                                      -27-

          (vii)  purchase any securities of any Person except short-term
                 investments made in the ordinary course of business; or

          (viii) grant a Security Interest.

     Notwithstanding the foregoing, Skybird shall be entitled to redeem Skybird
     Preferred Shares on a pro rata basis at $1.00 per share to the extent the
     Skybird current assets exceed the Skybird current liabilities in an amount
     not to exceed $77,500 without the prior written consent of the Purchaser.

4.4  Dealings or Operations re PNG Assets
     ------------------------------------

     Except in an emergency in order to prevent loss of life, injury to persons
     or damage to or loss of property, during the Interim Period, the Requisite
     Shareholders shall not permit Invasion directly or indirectly, through the
     activities of the Manager pursuant to the Management Agreement, without the
     prior written consent of the Purchaser (which consent shall not be
     unreasonably withheld), to:

     (a)  voluntarily assume any obligation or commitment with respect to the
          PNG Assets, where Invasion's share of the expenditure associated with
          such obligation or commitment is estimated by the Invasion Vendors,
          Skybird or Invasion to exceed $25,000;

     (b)  surrender, abandon or allow to expire any of the PNG Assets;

     (c)  propose or initiate the exercise of any right (including bidding
          rights at Crown sales, rights under area of mutual interest provisions
          and rights of first refusal) or option relative to, or arising as a
          result of the ownership of, any of the PNG Assets, or propose or
          initiate any operations on the Lands which have not commenced or have
          not been committed to by Invasion as of the Effective Date, if such
          exercise or option would result in either an obligation of Invasion
          after the Effective Date in excess of $25,000 or a material adverse
          effect on the value of any of the PNG Assets; or

     (d)  resign, or take any action which would result in its resignation or
          replacement, as operator of any of the Lands or the Petroleum and
          Natural Gas Rights.

     If the Requisite Shareholders or Invasion reasonably determines that any
     such expenditures or actions are necessary to prevent loss of life or
     injury to persons, damage to or loss of property, the Invasion Vendors or
     Skybird shall cause Invasion to give prompt notice to the Purchaser of such
     expenditures or actions and the Requisite Shareholders' or Invasion's
     estimate of the costs and expenses expended or to be expended in connection
     therewith.

4.5  Proposals for Dealings or Operations re PNG Assets
     --------------------------------------------------

     If Invasion directly or indirectly, through the activities of the Manager
     pursuant to the Management Agreement, receives notice of proposed
     operations, or the exercise of any


                                      -28-


     right or option, respecting the PNG Assets from a third party during the
     Interim Period in circumstances in which such operation or the exercise of
     such right or option would require the consent of the Purchaser pursuant to
     Sections 4.3 or 4.4, the following paragraphs shall apply to such operation
     or the exercise of such right or option (the "Proposal"):

     (a)  The Requisite Shareholders or Invasion directly or indirectly, through
          the activities of the Manager pursuant to the Management Agreement,
          shall give prompt notice of the Proposal to the Purchaser, including
          with such notice the particulars of such Proposal in reasonable
          detail, and whether Invasion recommends the exercise of its rights
          with respect to the Proposal.

     (b)  The Purchaser shall, not later than 4 Business Days prior to the time
          Invasion is required to make its election with respect to the Proposal
          (the "Election Time"), advise the Requisite Shareholders and Invasion,
          by written notice, whether it wishes Invasion to exercise its rights
          with respect to the Proposal, provided that failure of the Purchaser
          to provide such notice within such period shall be deemed to be an
          election by the Purchaser to have Invasion proceed with its
          recommendation with respect to the Proposal as specified in the notice
          delivered pursuant to Section 4.5(a).

     (c)  If the Requisite Shareholders agree with the proposed response to the
          Proposal requested by the Purchaser, the Requisite Shareholders shall
          cause Invasion directly or indirectly, through the activities of the
          Manager pursuant to the Management Agreement, to make the election
          requested by the Purchaser with respect to the Proposal within the
          period during which Invasion directly or indirectly, through the
          activities of the Manager pursuant to the Management Agreement, may
          respond to the Proposal.

     (d)  If the Requisite Shareholders disagree with the proposed response to
          the Proposal requested by the Purchaser, the Requisite Shareholders
          and the Purchaser shall meet at least 2 Business Days prior to the
          election time to discuss their differences. If consensus is not
          reached at that meeting, or if the Purchaser refuses to attend the
          meeting, Enron shall have the unilateral right, acting reasonably
          having regard to the best interests of Invasion, to determine the
          response of Invasion to the Proposal and such response shall be
          binding on the Purchaser.

     (e)  A request by the Purchaser not to consent to any Proposal required to
          preserve the existence of any of the PNG Assets shall not entitle the
          Purchaser to any reduction of the Purchase Price in the event that
          Invasion's interest therein is terminated or reduced as a result
          thereof, and such termination or reduction shall be deemed to be a
          Permitted Defect and shall not constitute a failure of the Vendors'
          representations and warranties pertaining to such PNG Assets.


                                      -29-

4.6  Prohibited Negotiations
     -----------------------

     Except in connection with the sale of the Purchased Shares and Enron Debt
     to the Purchaser hereto or as otherwise consented to by the Purchaser in
     writing, until the earlier of the expiry of the Interim Period or the
     termination of this Agreement in accordance with the terms hereof, neither
     Enron, Skybird, the Vendors nor any of their Affiliates shall:

     (a)  have any further negotiations with other potential purchasers of all
          or any portion of the Enron Debt, the Enron Royalty, the Purchased
          Shares, Share Rights in Invasion, the Skybird Invasion Shares or all
          or substantially all the PNG Assets and shall not directly or
          indirectly initiate, solicit, encourage or accept any other offer or
          proposal by any Person other than the Purchaser for the purchase or
          acquisition of all or any portion of the Enron Debt, the Enron
          Royalty, the Purchased Shares, the Skybird Invasion Shares or all or
          substantially all the PNG Assets; and

     (b)  provide information concerning Invasion's or Skybird's operations,
          finances, securities, assets or other business or affairs to any
          Person in furtherance of any matter pursuant to Section 4.6(a) or in
          furtherance of any contemplated corporate acquisition or merger.

4.7  Pre-Closing Events
     ------------------

     (a)  Prior to or concurrent with the Closing, the Invasion Vendors, Skybird
          and the Manager shall, if requested by the Purchaser, cause the
          Manager and Invasion to, terminate the Invasion Shareholder Agreement
          without further obligation or other liability to Invasion after the
          Closing Date and to terminate the Management Agreement effective May
          31, 2001 without obligation or other liability to Invasion, the
          Purchaser or its Affiliates for activities of the Manager prior to the
          Effective Date and releasing Invasion for any obligations owed by it
          to the Manager prior to the Effective Date.

     (b)  Prior to or concurrent with the Closing, the Skybird Vendors shall,
          and shall, if requested by the Purchaser, cause Skybird to terminate
          the Skybird Shareholder Agreement without further obligation or other
          liability to Skybird after the Closing Date.

4.8  Insurance
     ---------

     The Invasion Vendors and Skybird shall maintain, or cause Invasion to
     maintain Invasion's existing policies of insurance and surety bonds that
     provide certain coverage in favour of Invasion.  The Invasion Vendors and
     Skybird will or will cause Invasion to maintain such existing policies of
     insurance and surety bonds until 11:59 p.m. on the Closing Date.
     Thereafter the Purchaser will or will cause Invasion to procure and
     maintain any and all policies of insurance as the Purchaser or Invasion, at
     its or their respective cost and expense, deem advisable.  For the purposes
     of this Section 4.8 and


                                      -30-


     Invasion's insurance, all risk of loss with respect to Invasion or the PNG
     Assets or other properties of Invasion shall pass to the Purchaser at the
     Closing. After the Closing, the Invasion Vendors and Skybird shall have no
     further responsibility or duty to administer, in any fashion, claims under
     any insurance policies.

                                   ARTICLE 5
                   REPRESENTATIONS AND WARRANTIES OF PARTIES

5.1  Vendors' Representations and Warranties
     ---------------------------------------

     Each Vendor severally and not jointly, nor jointly and severally,
     represents and warrants to the Purchaser (as to itself only):

     (a)  Execution of Documents:  This Agreement has been duly executed and
          ----------------------
          delivered by the Vendor and all other documents executed and delivered
          by the Vendor pursuant hereto shall have been duly executed and
          delivered by the Vendor. This Agreement does, and such documents will,
          constitute legal, valid and binding obligations of the Vendor
          enforceable in accordance with their respective terms, subject to
          bankruptcy, insolvency, preference and other similar laws affecting
          creditors' rights generally and the discretion of courts with respect
          to equitable or discretionary remedies and defenses.

     (b)  Consents, Approvals or Authorizations:
          -------------------------------------

          (i)    With respect to an Invasion Vendor, to the knowledge of the
                 Invasion Vendor, no consent, approval or authorization of,
                 filing or registration with, or notification to, any
                 governmental authority, or consent, approval or authorization
                 of any Person, is required on behalf of the Invasion Vendor or
                 Invasion in connection with the execution and delivery of this
                 Agreement by the Invasion Vendor or the completion of the
                 transactions contemplated herein.

          (ii)   With respect to a Skybird Vendor, to the knowledge of the
                 Skybird Vendor, no consent, approval or authorization of,
                 filing or registration with, or notification to, any
                 governmental authority, or consent, approval or authorization
                 of any Person, is required on behalf of the Skybird Vendor,
                 Skybird or Invasion in connection with the execution and
                 delivery of this Agreement by the Skybird Vendor or the
                 completion of the transactions contemplated herein.

     (c)  No Conflict:  The execution and delivery of this Agreement, and the
          -----------
          other agreements and documents required to be delivered by a Vendor
          pursuant hereto, and the completion of the sale of the Invasion Shares
          or the Skybird Shares, as applicable, to the Purchaser in accordance
          with the terms of this Agreement are not and will not be in material
          violation or breach of, or be in material conflict with or require any
          material consent, authorization or approval under:


                                      -31-

          (i)    any term or provision of the constating documents of the
                 Vendor, if a corporation, or any agreement or document to which
                 the Vendor is a party or by which the Vendor is bound;

          (ii)   any permit or other governmental authorization to which the
                 Vendor is a party or by which the Vendor is bound; or

          (iii)  any Applicable Law or any judicial order, award, judgment or
                 decree applicable to the Vendor.

     (d)  Requisite Authority:  If a corporation or a trust, the Vendor:
          -------------------

          (i)    has been duly incorporated and/or organized, is validly
                 existing and is up to date with all its filings required under
                 the laws of its jurisdiction of incorporation or organization;
                 and

          (ii)   has taken all necessary action to authorize the transfer of the
                 Invasion Shares or Skybird Shares, as applicable, to the
                 Purchaser in accordance with the provisions of this Agreement
                 and to execute and deliver this Agreement and all other
                 documents to be executed and delivered by it pursuant hereto.

     (e)  Capacity:  If an individual, the Vendor has attained the age of
          --------
          majority and is legally competent to execute this Agreement and to
          take all actions required pursuant hereto.

     (f)  Title to Purchased Shares: As at the Closing Date, the Vendor will be
          -------------------------
          the registered and beneficial owner of the number of the Invasion
          Shares or the Skybird Shares, as applicable, set forth opposite its
          name on Schedule 1.2(b), Schedule 1.2(c) and/or Schedule 1.2(d) and
          will at such time have good and marketable title to such Invasion
          Shares or Skybird Shares, as applicable, free and clear of all
          Security Interests except those of the Purchaser arising pursuant to
          this Agreement.

     (g)  Tax Resident: The Vendor, if not Siren, is a resident of Canada within
          ------------
          the meaning of the Act and has complied with Section 116 of the Act
          with respect to the acquisition of the Purchased Shares or any portion
          thereof from any Person deemed to be a non-resident of Canada for
          purposes of the Act.

     (h)  Access:  To the knowledge of the Vendor, Invasion has provided the
          ------
          Purchaser access to all material and relevant information and
          documentation with respect to Invasion and the PNG Assets.

     (i)  No Fees etc.: Except as otherwise disclosed in writing to the
          ------------
          Purchaser, the Vendor has not incurred any obligation or liability,
          contingent or otherwise, for brokers' or finders' fees or commissions
          with respect to the transactions herein for which the Purchaser shall
          have any obligation or liability.


                                      -32-

5.2  Skybird Vendors' Representations and Warranties
     ------------------------------------------------

     Each Skybird Vendor severally and not jointly, nor jointly and severally
     represents and warrants to the Purchaser (as to itself only):

     (a)  No Conflict: The execution and delivery of this Agreement, and the
          -----------
          other agreements and documents required to be delivered by the Skybird
          Vendor pursuant hereto or Skybird, and the completion of the sale of
          the Skybird Shares to the Purchaser in accordance with the terms of
          this Agreement are not and will not be in material violation or breach
          of, or be in material conflict with or require any material consent,
          authorization or approval under:

          (i)    any term or provision of the constating documents of Skybird or
                 any agreement or document to which Skybird is a party or by
                 which Skybird is bound;

          (ii)   any permit or other governmental authorization to which Skybird
                 is a party or by which Skybird is bound; or

          (iii)  any Applicable Law or any judicial order, award, judgment or
                 decree applicable to Skybird.

     (b)  Capitalization of Skybird:  The authorized Share capital of Skybird
          -------------------------
          consists of an unlimited number of Skybird Common Shares and an
          unlimited number of Skybird Preferred Shares, of which 4,207 Skybird
          Common Shares and 4,207,503 Skybird Preferred Shares have been validly
          issued and are outstanding as fully paid and non-assessable Shares of
          Skybird. Other than the Skybird Shares, as at the Closing Date, no
          Person shall have any Share Right in Skybird or other agreement,
          option or privilege (whether pre-emptive, contractual or otherwise)
          capable of becoming a Share Right in Skybird, except as provided in
          this Agreement.

     (c)  Access: The Skybird Vendors and Skybird have provided the Purchaser
          ------
          with access to all material and relevant information and documentation
          with respect to Skybird and its assets.

     (d)  Skybird:  Skybird:
          -------

          (i)    has been duly incorporated and organized, is validly existing
                 and is up to date with all its filings required under the laws
                 of its jurisdiction of incorporation;

          (ii)   has taken all necessary corporate action to authorize the
                 transfer of the Skybird Shares to the Purchaser in accordance
                 with the provisions of this Agreement and to execute and
                 deliver all other documents to be executed and delivered on
                 behalf of Skybird pursuant to the transactions contemplated
                 herein;


                                      -33-


          (iii)  has all necessary corporate power and authority to own the
                 Skybird Invasion Shares and to carry on its business as now
                 being conducted; and

          (iv)   is duly qualified to own the Skybird Invasion Shares and to
                 carry on its business and is up to date with all of its filings
                 required to be made in each jurisdiction in which the nature of
                 the business conducted by it or the character of the properties
                 owned or leased by it makes such qualification necessary or
                 desirable.

     (e)  Minute Books:  The minute books for Skybird contain copies of all
          -------------
          constating documents and all minutes of all meetings and all consent
          resolutions of the directors, committees of directors and shareholders
          of Skybird and the registers therein are current, true and correct.

     (f)  Subsidiaries:  On the Closing Date, Skybird will have no Subsidiaries.
          ------------

     (g)  Financial Statements: The Skybird Financial Statements fairly present
          --------------------
          the financial position of Skybird as at the respective dates thereof,
          as well as the results of operations of Skybird for the periods
          covered thereby, as applicable, in accordance with GAAP.

     (h)  No Undisclosed Liabilities:  Skybird has no liabilities which would be
          --------------------------
          required by GAAP to be disclosed in the financial statements of
          Skybird (including the notes thereto).

     (i)  Applicable Law:  Skybird has not received nor delivered any written
          ---------------
          notices of non-compliance or alleged non-compliance of any provisions
          of Applicable Law, non-compliance with which would reasonably be
          expected to affect materially and adversely the business, financial
          condition or results of operations of Skybird taken as a whole.

     (j)  No Lawsuits or Claims:  There are no judgments and no material claims,
          ---------------------
          proceedings, actions or lawsuits in existence, contemplated or
          threatened against Skybird or with respect to any of the assets of
          Skybird or the interests of Skybird therein.

     (k)  Tax Matters: All Tax Returns of Skybird required by Applicable Law to
          -----------
          be filed prior to the Effective Date have been accurately prepared in
          all material respects and duly and properly filed and all liabilities
          for taxes for Skybird have been duly paid and satisfied on or before
          their respective due dates or will be paid and satisfied on a timely
          basis. As at the Closing Date, Skybird will have no liability for
          taxes for the year ending immediately prior to the Closing Date.

     (l)  Employees:  Skybird does not have any employees and has no outstanding
          ----------
          liabilities relating to any previous employees.



                                      -34-

     (m)  Disclosure re: Contracts and Commitments: Skybird is not a party to or
          -------------
          bound by any contract or agreement other than the Skybird Shareholder
          Agreement.

     (n)  No Material Adverse Change: From April 30, 2001 to the Closing Date
          --------------------------
          after taking into account the redemption of some of the Skybird
          Preferred Shares referred to in Section 4.3(b), there has been no
          material adverse change to any of the assets, business liabilities,
          financial condition or prospects of Skybird.

     (o)  Assets: Skybird's only material asset is the Skybird Invasion Shares
          ------
          and Skybird does not have, and never has had, title to or any interest
          (legal, equitable or otherwise) in any other undertaking, property or
          asset of any kind or description or wherever located.

     (p)  Title to Skybird Invasion Shares: As at the Closing Date, Skybird will
          --------------------------------
          be the registered and beneficial owner of the Skybird Invasion Shares
          and will at such time have good and marketable title to such Skybird
          Invasion Shares, free and clear of all Security Interests except those
          of the Purchaser arising pursuant to this Agreement.

     (q)  No Fees etc.:  Skybird has not incurred any obligation or liability,
          -------------
          contingent or otherwise, for brokers' or finders' fees or commissions
          with respect to the transactions herein for which the Purchaser shall
          have any obligation or liability.

5.3  Representations and Warranties of Manager
     -----------------------------------------
     The Manager represents and warrants to the Purchaser as follows:

     (a)  Management:  The Manager:
          ----------

          (i)    has been duly incorporated and organized, is validly existing
                 and is up to date with all its filings required under the laws
                 of its jurisdiction of incorporation; and

          (ii)   has taken all necessary corporate action to execute and deliver
                 this Agreement and all other documents to be executed and
                 delivered by it pursuant hereto.

     (a)  Execution of Documents:  This Agreement has been duly executed and
          ----------------------
          delivered by the Manager and all other documents executed and
          delivered by the Manager pursuant hereto shall have been duly executed
          and delivered by the Manager. This Agreement does, and such documents
          will, constitute legal, valid and binding obligations of the Manager
          enforceable in accordance with their respective terms, subject to
          bankruptcy, insolvency, preference and other similar laws affecting
          creditors' rights generally and the discretion of courts with respect
          to equitable or discretionary remedies and defenses.

     (b)  No Conflict: The execution and delivery of this Agreement, and the
          -----------
          other agreements and documents required to be delivered by the
          Invasion Vendors, the


                                      -35-


          Manager or Invasion pursuant hereto and the completion of the sale of
          the Invasion Shares to the Purchaser in accordance with the terms of
          this Agreement are not and will not be in material violation or breach
          of, or be in material conflict with or require any material consent,
          authorization or approval under:

          (i)    any term or provision of the constating documents of Invasion
                 or the Manager or any agreement or document to which Invasion
                 or the Manager is a party or by which Invasion or the Manager
                 is bound;

          (ii)   other than the Title and Operating Documents, any permit or
                 other governmental authorization to which Invasion or the
                 Manager is a party or by which Invasion or the Manager is
                 bound; or

          (iii)  any Applicable Law or any judicial order, award, judgment or
                 decree applicable to Invasion or the Manager.

     (c)  Capitalization of Invasion:  The authorized Share capital of Invasion
          --------------------------
          consists of an unlimited number of Class A Common Shares, an unlimited
          number of Class B Common Shares and an unlimited number of Class C
          Common Shares, of which 12,857,872 Class B Common Shares and 168
          Invasion C Shares have been validly issued and are outstanding as
          fully paid and non-assessable shares of Invasion. Other than the Total
          Invasion Shares, as at the Closing Date, no Person shall have any
          Share Right or other agreement, option or privilege (whether pre-
          emptive, contractual or otherwise) capable of becoming a Share Right,
          except as provided in this Agreement.

     (d)  Access: Invasion and the Manager have provided the Purchaser access to
          ------
          all material and relevant information and documentation with respect
          to Invasion and the PNG Assets.

     (e)  Invasion:  Invasion:
          --------

          (i)    has been duly incorporated and organized, is validly existing
                 and is up to date with all its filings required under the laws
                 of its jurisdiction of incorporation;

          (ii)   has taken all necessary corporate action to authorize the
                 transfer of the Invasion Shares to the Purchaser in accordance
                 with the provisions of this Agreement and to execute and
                 deliver all other documents to be executed and delivered on
                 behalf of Invasion pursuant to the transactions contemplated
                 herein;

          (iii)  has all necessary corporate power and authority to own or lease
                 its properties and the PNG Assets and to carry on its business
                 as now being conducted; and


                                      -36-

          (iv)   is duly qualified to own or lease its properties and the PNG
                 Assets and to carry on its business and is up to date with all
                 of its filings required to be made in each jurisdiction in
                 which the nature of the business conducted by it or the
                 character of the properties and the PNG Assets owned or leased
                 by it makes such qualification necessary or desirable.

     (f)  Minute Books:  The minute books for Invasion contain copies of all
          -------------
          constating documents and all minutes of all meetings and all consent
          resolutions of the directors, committees of directors and shareholders
          of Invasion and the registers therein are current, true and correct.

     (g)  Subsidiaries: On the Closing Date, Invasion will have no Subsidiaries.
          ------------

     (h)  Financial Statements:  The Financial Statements fairly present the
          --------------------
          financial position of Invasion as at the respective dates thereof, as
          well as the results of operations and changes in financial position of
          Invasion for the periods covered thereby, as applicable, in accordance
          with GAAP consistently applied and the accounting policies set out in
          the notes to such Financial Statements.

     (i)  No Undisclosed Liabilities: Except as disclosed to the
          --------------------------
          Purchaser in this Agreement or the Schedules to this Agreement, and
          except for:

          (i)    liabilities which are disclosed or adequately provided for in
                 the Financial Statements;

          (ii)   liabilities incurred in the ordinary course of business of
                 Invasion subsequent to the date of the Effective Date Balance
                 Sheet which have no material adverse affect on Invasion;

          (iii)  liabilities as a result of transactions contemplated by this
                 Agreement; and

          (iv)   liabilities with respect to Abandonment and Reclamation
                 Obligations;

          Invasion has no liabilities which would be required by GAAP to be
          disclosed in the financial statements of Invasion (including the notes
          thereto) and which in the aggregate are material to the business,
          financial condition and results of operations of Invasion taken as a
          whole.

     (j)  Applicable Law:
          --------------

          (i)    Invasion directly or indirectly has not received nor delivered
                 any written notices of non-compliance or alleged non-compliance
                 of any provisions of Applicable Law, non-compliance with which
                 would reasonably be expected to affect materially and adversely
                 the business, financial condition or results of operations of
                 Invasion taken as a whole.

          (ii)   Invasion or the relevant operator has obtained all permits,
                 licences and other authorizations which are required under
                 Environmental Law to own


                                      -37-


                 or operate the PNG Assets and the failure of which to obtain
                 would have a material adverse effect upon the current use or
                 operation of such PNG Assets. Invasion directly or indirectly,
                 through the activities of the Manager pursuant to the
                 Management Agreement, has not received any written notice of
                 any material non-compliance with Environmental Law, the failure
                 with which to comply would materially adversely affect the
                 current use or operation of the PNG Assets.

     (k)  Notices: Invasion directly or indirectly has not received any notice
          -------
          of default, which remains in effect or has not been rectified by the
          Effective Date under the Title and Operating Documents.

     (l)  No Lawsuits or Claims:  There are no judgments and no material claims,
          ---------------------
          proceedings, actions or lawsuits in existence, contemplated or
          threatened against Invasion or with respect to any of the PNG Assets
          of Invasion or the interests of Invasion therein.

     (m)  Tax Matters:  Except as disclosed to the Purchaser with respect to the
          -----------
          refiling of the Invasion Tax Returns for the year ended August 31,
          2000 for a reallocation of the financing pre-paid interest expenses,
          all Tax Returns of Invasion required by Applicable Law to be filed
          prior to the Effective Date have been accurately prepared in all
          material respects and duly and properly filed and all liabilities for
          taxes of Invasion have been duly paid and satisfied on or before their
          respective due dates or will be paid and satisfied on a timely basis.

     (n)  Employees: Invasion does not have any employees and has no outstanding
          ---------
          liabilities in excess of $10,000 relating to any previous employees
          including those with respect to Workers Compensation.

     (o)  Disclosure re: Contracts and Commitments: Other than in respect of the
          Title and Operating Documents and, prior to Closing, the Enron
          Royalty, Schedule 5.1(p) is a complete and correct list of all of the
          following to which Invasion is a party or by which it is bound, or in
          the case of items (ii) and (ix), to which it adheres or in which it
          participates (complete and correct copies of each of which, as in
          effect on the Closing Date, have been made available to the
          Purchaser):

          (i)    any management or employment contract or other contract
                 providing for personal services with respect to any period
                 after Closing with any officer, consultant, director, employee
                 or any other Person;

          (ii)   any written agreements that contain any liability of Invasion
                 after the Effective Date for severance pay, liabilities or
                 obligations in respect of termination or severance of
                 employment;

          (iii)  any contract or agreement under which Invasion has outstanding
                 indebtedness for borrowed money or the deferred purchase price
                 of


                                      -38-


                 property in an amount which in the aggregate is in excess of
                 $100,000 or has the right or obligation to incur any such
                 indebtedness;

          (iv)   any guarantee or surety entered into by Invasion;

          (v)    any confidentiality or non-competition agreement which
                 restricts the right of Invasion to engage in any type of
                 business after the consummation of the transactions
                 contemplated by this Agreement;

          (vi)   each Futures Transaction;

          (vii)  any Take or Pay Delivery Obligations or Take or Pay Payments;

          (viii) any agreement respecting the firm transportation of Petroleum
                 Substances having a term which expires more than 91 days after
                 the Closing Date or respecting the dedication of Petroleum
                 Substances from the Lands to any Person;

          (ix)   any production sale agreements or arrangements under which
                 Invasion, or any third party acting on behalf of Invasion, is
                 obligated to sell or deliver Petroleum Substances to be
                 allocated to the Petroleum and Natural Gas Rights, other than
                 contracts which are terminable on not more than 30 days notice;

          (x)    any agreements or arrangements respecting the processing of
                 Petroleum Substances of other Persons using the Tangibles or
                 the processing of Petroleum Substances from the Lands by other
                 Persons where the amount paid or payable pursuant to such
                 individual arrangements or agreements result in fees received
                 from such Persons or paid to such Persons; and

          (xi)   all material insurance policies and surety bonds, other than
                 directors' and officers' liability policies, of Invasion or by
                 which Invasion or any of its properties or PNG Assets are
                 covered against present losses, all of which are now, and will
                 at Closing be, in full force and effect;

          Invasion is not in default of its obligations under any of the
          foregoing contracts and commitments.

     (p)  No Material Adverse Change: From March 31, 2001 to the Closing Date,
          --------------------------
          there has been no material adverse change to any of the PNG Assets
          (other than production of Petroleum Substances in the ordinary course)
          or the business, liabilities, financial condition or prospects of
          Invasion, except for matters and risks which are generally applicable
          to the oil and gas industry in Canada.

     (q)  PNG Assets:  With respect to the PNG Assets:
          ----------

          (i)    other than Permitted Encumbrances, (i) neither the Vendors,
                 Invasion nor the Manager have alienated or encumbered the PNG
                 Assets or any part or


                                      -39-

                 portion thereof, (ii) neither Invasion nor the Manager are
                 aware of having committed any act or omission whereby
                 Invasion's interest in and to the PNG Assets or any part or
                 portion thereof may be cancelled or determined, and (iii) the
                 PNG Assets are free and clear of all Burdens, conversion rights
                 and other claims of third parties;

          (ii)   all amounts due and payable to third parties prior to the
                 Effective Date and pertaining to the PNG Assets have been fully
                 paid, including, without limitation (i) any and all ad valorem
                 and property taxes including royalties and calculations of gas
                 cost allowance, (ii) any and all production, severance and
                 similar taxes, charges and assessments based upon or measured
                 by the ownership or production of Petroleum Substances or any
                 of them or the receipt of proceeds therefor, and (iii) all
                 amounts due and payable in connection with Permitted
                 Encumbrances, provided however, in the case of any and all
                 amounts due and payable prior to the time Invasion acquired an
                 interest in and to the PNG Assets to which such amounts
                 pertain, the Manager makes this representation and warranty
                 only based upon its knowledge;

          (iii)  there are no financial commitments which are due as of the
                 Effective Date or which may become due by virtue of matters
                 occurring or arising prior to the Closing Date, other than
                 usual operating expenses incurred in the normal conduct of
                 operations;

          (iv)   except for any production contracts listed in Schedule 5.1(p),
                 Invasion is not a party to and Invasion's interest in and to
                 the PNG Assets is not otherwise bound or affected by any
                 production sales contracts which are not terminable on 45 days
                 or less notice without penalty; and

          (v)    Neither Invasion nor the Manager has received:

                 (A)  any orders or directives which relate to environmental
                      matters and which require any work, repairs, construction
                      or capital expenditures with respect to the PNG Assets,
                      where such orders or directives have not been complied
                      with in all material respects; or

                 (B)  any demand or notice issued with respect to the breach of
                      any Applicable Law applicable to the PNG Assets,
                      including, without limitation, respecting the use,
                      storage, treatment, transportation or disposition of
                      environmental contaminants, which demand or notice remains
                      outstanding on the Closing Date.

     (r)  Wells:
          -----

          (i)    Each Well located on the Lands that has been drilled for the
                 purpose of producing Petroleum Substances has been drilled at a
                 location for which an off-target production penalty is not
                 applicable under Applicable Law.


                                      -40-

          (ii)   No notice has been received under the Applicable Law that a
                 Well located on the Lands has been produced in excess of
                 regulatory production allowables, and there is no pending
                 change in those production allowables, other than as may
                 generally be applicable through a change in Applicable Law.

     (s)  Area of Mutual Interest: None of the Title and Operating Documents
          -----------------------
          include an area of mutual interest that remains in effect as of the
          Closing Date.

     (t)  Offset Obligations: Invasion has not received any notice that a Lease
          ------------------
          is subject to an offset obligation, including the obligation to drill
          a well, surrender rights or pay compensatory royalties, other than
          those which have been disclosed to the Purchaser in writing and is not
          aware of any particular circumstances that has created such an offset
          obligation.

     (u)  No Fees etc.: Except as otherwise disclosed in writing to the
          ------------
          Purchaser, Invasion has not incurred any obligation or liability,
          contingent or otherwise, for brokers' or finders' fees or commissions
          with respect to the transactions herein for which the Purchaser shall
          have any obligation or liability.

5.4  Representations and Warranties of Enron
     ---------------------------------------
     Enron represents and warrants to the Purchaser as follows:

     (a)  The Enron Debt is, and will at Closing be, outstanding. Enron is, and
          will be at Closing, the owner of the Enron Debt and has the requisite
          power and authority to sell the Enron Debt to the Purchaser as
          contemplated herein.

     (b)  The Enron Royalty was as of the Effective Date outstanding. Enron is,
          and will be at the time of the sale of such royalty to Invasion, the
          owner of the Enron Royalty and has the requisite power and authority
          to sell the Enron Royalty to Invasion as contemplated herein.

     (c)  Enron has disclosed all details or provided the Purchaser with access
          to all material and relevant information and documentation with
          respect to the Enron Debt.

     (d)  Other than as is specified in the definition of Adjusted Working
          Capital, or with respect to the Enron Debt, the Enron Royalty (only as
          to the Effective Date), Futures Transactions or other contracts each
          of which is identified in Schedule 5.1(p) or disclosed in writing to
          the Purchaser, there are no debts, payments or other liabilities,
          current or otherwise, owing by Invasion to Enron.

5.5  Purchaser's Representations And Warranties
     ------------------------------------------
     The Purchaser and Wiser jointly and severally represent and warrant to the
     Vendors and Enron that:


                                      -41-

     (a)  Standing: The Purchaser is a corporation, duly organized, validly
          --------
          existing under the laws of its jurisdiction of incorporation, and duly
          registered, authorized to carry on business in and a resident of the
          Province of Nova Scotia. Wiser is a corporation duly organized,
          validly existing under the laws of its jurisdiction of incorporation,
          and duly registered, authorized to carry on business in and a resident
          of the State of Delaware.

     (b)  Requisite Authority and Enforceability: Each of the Purchaser and
          --------------------------------------
          Wiser has the requisite corporate capacity, power and authority to
          execute this Agreement and the other agreements and documents required
          to be delivered hereby and to perform the obligations to which it
          thereby becomes subject, including the purchase of the Purchased
          Shares and the Enron Debt by the Purchaser in accordance with the
          provisions of this Agreement. The Board of Directors of Wiser has
          approved the purchase of the Purchased Shares and the Enron Debt as
          contemplated herein. This Agreement has been duly executed and
          delivered by the Purchaser and Wiser, and this Agreement constitutes,
          and all other documents executed and delivered on behalf of the
          Purchaser and Wiser hereunder shall, when executed and delivered
          constitute, valid and binding obligations of the Purchaser and Wiser
          enforceable in accordance with their respective terms and conditions,
          subject to the qualification that such enforceability may be subject
          to (i) bankruptcy, insolvency, fraudulent preference, reorganization
          or other laws affecting creditors' rights generally, and (ii) general
          principles of equity (regardless of whether such enforceability is
          considered in a proceeding at equity or law).

     (c)  No Conflict: The execution and delivery of this Agreement, and the
          -----------
          other agreements and documents required to be delivered by it pursuant
          hereto, and the completion of the purchase of the Purchased Shares and
          the Enron Debt by the Purchaser in accordance with the terms of this
          Agreement are not and will not be in violation or breach of, or be in
          conflict with or require any consent, authorization or approval under:

          (i)    any term or provision of the constating documents of the
                 Purchaser;

          (ii)   any permit or authority to which the Purchaser is a party or by
                 which the Purchaser is bound; or

          (iii)  Applicable Law or any judicial order, award, judgment or decree
                 applicable to the Purchaser.

     (d)  No Lawsuits or Claims: There are no actions, suits or proceedings
          pending or, to the knowledge of the Purchaser or Wiser, threatened
          against the Purchaser seeking relief which would prevent or materially
          hinder the consummation of the transactions contemplated by this
          Agreement.

     (e)  No Fees etc.: Neither the Purchaser nor Wiser has incurred any
          ------------
          obligation or liability, contingent or otherwise, for brokers' or
          finders' fees or commissions with


                                      -42-


          respect to the transactions herein for which the Vendors, Enron,
          Invasion or Skybird (in the case of a purchase pursuant to Section
          7.4) shall have any obligation or liability.

5.6  Survival Of Representations And Warranties
     ------------------------------------------

     Each Party acknowledges that the other may, subject to Article 8, rely on
     the representations and warranties made by such Party pursuant to Sections
     5.1, 5.2, 5.3, 5.4 or 5.5, as the case may be.  The representations and
     warranties in Sections 5.1, 5.2, 5.3, 5.4 and 5.5 shall be true on the
     Effective Date and on the Closing Date, and such representations and
     warranties shall continue in full force and effect and shall survive the
     Closing Date for the Survival Period applicable thereto for the benefit of
     the Party for which such representations and warranties were made.

5.7  No Additional Representations or Warranties
     --------------------------------------------

     Except as and to the extent set forth in Sections 5.1, 5.2 or 5.3, the
     Vendors and the Manager make no representations or warranties whatsoever,
     and disclaim all liability and responsibility for any representation,
     warranty, statement or information made or communicated (orally or in
     writing) to the Purchaser (including any opinion, information or advice
     which may have been provided to the Purchaser by any officer, shareholder,
     director, employee, agent, consultant or representative of Invasion, the
     Manager, the Vendors, Affiliates of the Vendors, Vendors' Counsel or any
     other agent, consultant, representative or Person, collectively referred to
     as the "Vendors' Representatives").  Without limiting the generality of the
     foregoing, the Vendors and, except as and to the extent, if any, set forth
     in Section 5.3, the Manager make no representations or warranties as to:

     (a)  title to any of Invasion's interests in any properties or assets,
          including the PNG Assets;

     (b)  the quantity, quality or recoverability of Petroleum Substances
          respecting the Lands;

     (c)  any estimates of the value of the PNG Assets or the revenues
          applicable to future production from the Lands;

     (d)  any engineering, geological, environmental or other interpretations or
          economic evaluations respecting the PNG Assets;

     (e)  the rates of production of Petroleum Substances from the Lands;

     (f)  the quality, condition or serviceability of the PNG Assets;

     (g)  the suitability of any of the PNG Assets for use for any purpose;

     (h)  any information provided or made available to the Purchaser by the
          Vendors, the Manager, Invasion or the Vendors' Representatives
          including the Title and


                                      -43-


          Operating Documents, the Financial Statements, any engineering report
          or update, books, accounts, records, minute books, Tax Returns and
          filings and other information and documents of each of Invasion, the
          Manager and the Vendors; or

     (i)  any information provided and made available to the Purchaser by the
          Skybird Vendors with respect to the business, operations, assets,
          liabilities, capitalization or any other information relating to
          Skybird.

5.8  No Merger
     ---------

     The representations and warranties in Sections 5.1, 5.2, 5.3, 5.4 and 5.5
     shall be deemed to apply to all transfers, assignments and other documents
     conveying any of the Purchased Shares from the Vendors to the Purchaser.
     Until the end of the Survival Period applicable thereto, there shall not be
     any merger of any of such representations or warranties in such
     assignments, transfers or other documents, notwithstanding any rule of law,
     equity or statute to the contrary, and all such rules are hereby waived.

                                   ARTICLE 6
                             CONDITIONS TO CLOSING

6.1  Conditions to the Obligations of the Purchaser to Close
     -------------------------------------------------------

     The obligation of the Purchaser to complete the purchase of the Purchased
     Shares and the Enron Debt from the Vendors and Enron, as applicable,
     pursuant to this Agreement are subject to the fulfilment, on or prior to
     the Closing Date, of the following conditions precedent:

     (a)  Representations and Warranties of the Vendors: All representations and
          ---------------------------------------------
          warranties of the Vendors (except those made by the Skybird Vendors in
          Section 5.2 and Enron in Section 5.4) contained in this Agreement
          shall be true at and as of the Effective Date and the Closing Date as
          if made then in each case, except for inaccuracies which are not in
          the aggregate material, and a Certificate to that effect from the
          Requisite Shareholders (on behalf of the Vendors) shall have been
          delivered to the Purchaser.

     (b)  Representations and Warranties of the Skybird Vendors: All
          -----------------------------------------------------
          representations and warranties of the Skybird Vendors (except those
          made by the Skybird Vendors in Section 5.1) contained in this
          Agreement shall be true at and as of the Effective Date and the
          Closing Date as if made then in each case, except for inaccuracies
          which are not in the aggregate material, and a Certificate to that
          effect from Yellowbird and C2Sky (on behalf of the Skybird Vendors)
          shall have been delivered to the Purchaser.

     (c)  Representations and Warranties of Enron:  All representations and
          ---------------------------------------
          warranties of Enron (except those covered by (a) above) contained in
          this Agreement shall be true at and as of the Effective Date and the
          Closing Date as if made then in each


                                      -44-


          case, except for inaccuracies which are not in the aggregate material,
          and a Certificate to that effect from Enron shall have been delivered
          to the Purchaser.

     (d)  Representations and Warranties of the Manager: All representations and
          ---------------------------------------------
          warranties of the Manager contained in this Agreement shall be true at
          and as of the Effective Date and the Closing Date as if made then in
          each case, except for inaccuracies which are not in the aggregate
          material, and a Certificate to that effect from the Manager shall have
          been delivered to the Purchaser.

     (e)  Covenants and Agreements - Invasion Vendors: The Invasion Vendors
          -------------------------------------------
          shall have complied with and performed in all material respects all
          covenants and agreements required by this Agreement to be complied
          with and performed by the Invasion Vendors at or prior to the Closing
          Date and a Certificate to that effect from the Requisite Shareholders
          (on behalf of the Invasion Vendors) shall have been delivered to the
          Purchaser.

     (f)  Covenants and Agreements - Skybird Vendors: The Skybird Vendors shall
          ------------------------------------------
          have complied with and performed in all material respects all
          covenants and agreements required by this Agreement to be complied
          with and performed by the Skybird Vendors at or prior to the Closing
          Date and a Certificate to that effect from Yellowbird and C2Sky (on
          behalf of the Skybird Vendors) shall have been delivered to the
          Purchaser.

     (g)  Covenants and Agreements - the Manager: The Manager shall have
          --------------------------------------
          complied with and performed in all material respects all covenants and
          agreements required by this Agreement to be complied with and
          performed by the Manager at or prior to the Closing Date and a
          Certificate to that effect from the Manager shall have been delivered
          to the Purchaser.

     (h)  Invasion Minority Shareholders: The Requisite Shareholders shall have
          ------------------------------
          provided written notice to the Invasion Minority Shareholders
          requiring such Invasion Minority Shareholders to sell their Invasion
          Shares to the Purchaser hereunder in accordance with Section 3.3(a)(A)
          of the Invasion Shareholder Agreement.

     (i)  Skybird Minority Shareholders: The Majority Shareholders shall have
          -----------------------------
          provided written notice to the Skybird Minority Shareholders requiring
          such Skybird Minority Shareholders to sell their Skybird Shares to the
          Purchaser hereunder in accordance with Section 4.3 of the Skybird
          Shareholder Agreement.

     (j)  Invasion Tendered Shares:  The Total Invasion Shares tendered to the
          ------------------------
          Purchaser directly or indirectly hereunder on Closing shall equal at
          least 90% of the Total Invasion Shares.

     (k)  Skybird Tendered Shares: The Skybird Vendors shall tender at least 90%
          -----------------------
          of the Skybird Shares to the Purchaser hereunder on Closing.


                                      -45-

     (l)  Release of Security: The Vendors shall obtain an Encumbrance Discharge
          -------------------
          in respect of all Security Interests to the extent such security
          encumbers the PNG Assets (except to the extent that such Security
          Interests are Permitted Encumbrances) and/or the Invasion Shares
          and/or the Skybird Invasion Shares.

     (m)  Release of Security:  The Skybird Vendors shall obtain an Encumbrance
          -------------------
          Discharge in respect of all Security Interests to the extent such
          security encumbers the Skybird Shares.

     (n)  No Material Adverse Changes: The Purchaser shall be satisfied that
          ---------------------------
          there has been no material adverse change since March 31, 2001 to the
          Closing Date to any of the PNG Assets (other than production of
          Petroleum Substances in the ordinary course) or the business,
          liabilities, financial condition or prospects of Invasion, except for
          matters and risks which are generally applicable to the oil and gas
          industry in Canada and a Certificate to that effect from the Manager
          (on behalf of the Vendors) shall have been delivered to the Purchaser.

     (o)  Closing Deliveries:  The Purchaser shall have received delivery of all
          ------------------
          documents required to be delivered by Enron and the Vendors pursuant
          to Sections 3.3(a) and 3.3(b).

     (p)  Bank Accounts: All bank accounts and safety deposit boxes maintained
          -------------
          by Invasion and Skybird shall have been identified and all rights to
          draw thereon or to have access thereto shall have been assigned to the
          Purchaser. In the event that the Purchaser is obligated to acquire the
          Skybird Invasion Shares pursuant to Section 7.4, this Clause shall be
          amended to delete the reference to the Skybird bank accounts and
          safety deposit boxes.

     (q)  Outside Date: The Closing shall have occurred not later than May 25,
          ------------
          2001.

     (r)  Enron Royalty: Invasion shall have purchased immediately prior to
          -------------
          Closing the Enron Royalty for an amount equal to 4.81% of the Purchase
          Price as calculated at the Closing Date.

6.2  Conditions to Obligations of Enron and Vendors to Close
     -------------------------------------------------------

     The obligation of Enron and the Vendors to complete the sale of the
     Purchased Shares, and the Enron Debt to the Purchaser, pursuant to this
     Agreement is subject to the satisfaction at or prior to the Closing Date of
     the following conditions precedent:

     (a)  Representations and Warranties: All representations and warranties of
          ------------------------------
          the Purchaser and Wiser contained in this Agreement shall be true at
          the Effective Date and the Closing Date as if made then in each case,
          except for inaccuracies which are not in the aggregate material, and a
          Certificate from the Purchaser to that effect shall have been
          delivered to Enron and the Vendors.


                                      -46-

     (b)  Covenants and Agreements:  The Purchaser shall have complied with and
          ------------------------
          performed in all material respects all covenants and agreements
          required by this Agreement to be complied with and performed by the
          Purchaser at or prior to the Closing Date and a Certificate to that
          effect from the Purchaser shall have been delivered to Enron and the
          Vendors.

     (c)  Closing Deliveries: Enron and the Vendors shall have received delivery
          ------------------
          of the Purchase Price and all documents required to be delivered by
          the Purchaser pursuant to Section 3.3(c).

     (d)  Outside Date: The Closing shall have occurred not later than May 25,
          ------------
          2001.

6.3  Parties To Exercise Diligence With Respect To Conditions, etc.
     --------------------------------------------------------------

     Each Party shall proceed diligently, honestly and in good faith and use all
     reasonable efforts with respect to all matters within its control to
     satisfy the conditions referred to in Sections 6.1 and 6.2.  In particular:

     (a)  The Vendors and the Purchaser shall each use all of their respective
          reasonable efforts, and shall cooperate with each other, to obtain all
          governmental and regulatory filings, approvals and consents as may be
          or become necessary for or in connection with the consummation of the
          transactions contemplated by this Agreement, including the Purchaser
          and the Vendors shall cooperate to make reasonable efforts to respond
          to any governmental request or inquiry with respect thereto, but none
          of the Purchaser or the Vendors, or any of their Affiliates, shall be
          required to make any payment (other than for reasonable legal fees)
          that it is not presently contractually required to make, divest any
          assets, make any change in the conduct of its business, accept any
          limitation on the future conduct of its business, enter into any other
          agreement or arrangement with any Person that it is not presently
          contractually required to enter into, accept any significant
          modification in any existing agreement or arrangement, or agree to any
          of the foregoing, or to litigate or participate in administrative
          actions regarding such filings.

     (b)  The Purchaser will, at the request of the Vendors, from time to time
          during the Interim Period, provide the Vendors and their
          representatives with copies of all applications, filings,
          notifications, submissions and other correspondence or documents
          (including drafts thereof) related to the satisfaction of the
          conditions to Closing together with such written advice and
          information with respect to the status of the Purchaser's efforts to
          obtain the satisfaction of the conditions to Closing as the Vendors
          may reasonably request.

6.4  Waiver of Conditions
     --------------------

     The conditions in Section 6.1 are for the sole benefit of the Purchaser and
     the conditions in Section 6.2 are for the sole benefit of Enron and the
     Vendors.  The Requisite


                                      -47-


     Shareholders, in the case of Section 6.2, and the Purchaser, in the case of
     Section 6.1, may waive any of them, in whole or in part, by written notice
     to the other Parties.

6.5  Failure To Satisfy Conditions
     -----------------------------

     If any of the conditions in Sections 6.1 or 6.2 has not been satisfied at
     or before the Closing Date and such condition has not been waived by the
     Purchaser, in the case of Section 6.1 or the Requisite Shareholders, in the
     case of Section 6.2, the Requisite Shareholders or the Purchasers, as
     applicable, may terminate this Agreement pursuant to Section 7.1 by written
     notice to the other Parties prior to the Closing.

                                   ARTICLE 7
                                  TERMINATION

7.1  Grounds for Termination
     -----------------------

     This Agreement may be terminated prior to the Closing Date:

     (a)  by the mutual written agreement of the Requisite Shareholders and the
          Purchaser;

     (b)  in accordance with Section 6.5 by the Party and in the circumstances
          contemplated thereby; or

     (c)  by the Requisite Shareholders or the Purchaser if the consummation of
          such transactions would violate any non-appealable final order, decree
          or judgment of any court or governmental body having competent
          jurisdiction;

     provided that, notwithstanding anything to the contrary express or implied
     herein, a Party shall not be allowed to exercise any right of termination
     pursuant to this Section 7.1 if the event giving rise to such right is due
     to a Purchase Agreement Default by such Party.

7.2  Effect of Termination
     ---------------------

     If this Agreement is terminated by a Party as permitted under Section 7.1
     hereof:

     (a)  except as provided under Section 7.3, such termination shall be
          without liability of any Party to any other Party to this Agreement,
          or to any of their shareholders, directors, officers, employees,
          agents, consultants or representatives, and the Parties shall be
          released from all of their obligations under this Agreement; and

     (b)  the Purchaser shall promptly destroy or return to Enron, the Vendors
          or Skybird, all materials delivered to the Purchaser by Enron, the
          Vendors or Skybird hereunder, together with all copies of them that
          may have been made by or for the Purchaser.


                                      -48-

7.3  Entitlement to Deposit on Termination
     -------------------------------------

     (a)  If this Agreement is terminated pursuant to Section 7.1 due to a
          Purchase Agreement Default by the Purchaser, the Deposit together with
          all interest earned thereon shall be forfeited to and retained by the
          Vendors for their own account absolutely (to be allocated to the
          Vendors in accordance with the allocation set forth in Section 2.2(b))
          as a genuine pre-estimate by the Vendors and the Purchaser of all
          damages, costs, losses and expenses suffered or incurred by the
          Vendors as a consequence of such termination.

     (b)  If this Agreement is terminated for any reason or circumstance other
          than those described in Section 7.3(a), the Deposit together with all
          interest earned thereon shall be returned within 1 Business Day to the
          Purchaser for its account absolutely.

     (c)  The Parties agree and acknowledge that return or retention (as
          applicable) of the Deposit pursuant to Sections 7.3(a) or (b) shall be
          the sole remedy for termination of the Agreement under Section 7.1 and
          that, in no event, shall any Party be entitled to recover any damages,
          costs, costs or expenses in excess of the amount of the Deposit for
          such termination.

7.4  Remedy for Failure to Tender
     ----------------------------

     Notwithstanding anything else contained in this Agreement or any documents
     provided pursuant hereto, if the Purchaser is unable to complete the
     acquisition of the Skybird Shares due to a failure of the Skybird Vendors
     to meet the conditions precedent set forth in Sections 6.1(a), 6.1(b),
     6.1(f), 6.1(i), 6.1(k), 6.1(m), 6.1(o) with respect to Section 3.3(b)
     and/or 6.1(p), the sole and exclusive remedy available to the Purchaser in
     such circumstance shall be to purchase the Skybird Invasion Shares from
     Skybird pursuant to the terms of this Agreement and, in such circumstance,
     the Purchaser agrees to purchase and Skybird agrees to sell all of the
     Skybird Invasion Shares upon the same terms and conditions applicable to
     all Invasion Vendors under this Agreement and Skybird shall be deemed to
     be, for all purposes, an Invasion Vendor and Schedule 1.2(b) shall be
     amended accordingly and for certainty, Skybird shall be bound pursuant to
     the terms hereof as if it had initially executed this Agreement as an
     Invasion Vendor.

     If, pursuant to the operation of this Section 7.4, the Purchaser purchases
     and Skybird sells to the Purchaser the Skybird Invasion Shares, each of
     Kanovsky and Paulson hereby severally guarantees the payment of any amount
     owed by Skybird, in its capacity as an Invasion Vendor, to the Purchaser
     and its Additional Indemnitees under Article 8, provided that the Purchaser
     and its Additional Indemnitees shall only be entitled to request payment
     from Kanovsky and Paulson pursuant hereto if Skybird fails to pay any
     amounts owed by it under Article 8 within 60 days of receiving a Notice of
     Claim unless such claim is being contested in good faith by the Invasion
     Vendors.  For certainty, if the Purchaser purchases the Skybird Invasion
     Shares pursuant to this Section 7.4, the liability of the Skybird Vendors
     under Article 8 shall terminate and Skybird or Kanovsky and


                                      -49-


     Paulson, as applicable, shall become liable under Article 8 as an Invasion
     Vendor. Provided that in, for certainty, any liability of Paulson and
     Kanovsky under this guarantee shall be allocated equally.

                                   ARTICLE 8
                         LIABILITY AND INDEMNIFICATION
                         -----------------------------

8.1  Defined Terms
     -------------

     In this Article 8:

     "Additional Indemnitees" means, with respect to any Person to which an
     indemnity is granted pursuant to this Article 8, its Affiliates and the
     respective directors, officers, servants, agents, advisors and employees of
     that Person and its Affiliates.

     "Indemnified Losses" means all losses, costs, damages, expenses, charges,
     fines, penalties, assessments or other liabilities whatsoever, but does not
     include consequential, incidental, economic or punitive losses, damages or
     claims.

     "Notice of Claim" means a notice by a Vendor or the Purchaser, as
     applicable, on behalf of itself or one or more Additional Indemnities (if
     applicable) of a claim for Indemnified Losses pursuant to Section 8.2, 8.3,
     8.4 or 8.5, as applicable, together with detailed particulars as to the
     nature and amount of the claim, the basis which it is sought and the
     provisions of this Agreement applicable to such claim.

8.2  Responsibility of Vendors
     -------------------------

     Subject to the limitations set forth herein, the Vendors shall:

     (a)  be liable to the Purchaser and its Additional Indemnities for all
          Indemnified Losses which any one or more of them may suffer, sustain,
          pay or incur; and

     (b)  indemnify and save harmless the Purchaser and its Additional
          Indemnities from and against all Indemnified Losses which may be
          brought against or suffered by any one or more of them or which any
          one or more of them may sustain, pay or incur;

     as a direct result of any breach by (i) the Vendors of, or any inaccuracy
     of, any representation or warranty contained in Section 5.1, or (ii)
     notwithstanding any breach of 5.3(a) and 5.3(b), the Manager of, or any
     inaccuracy of, any representation or warranty of the Manager contained in
     Section 5.3 (except those representations in Section 5.3(a) and 5.3(b) for
     which the Vendors shall have no liability).

8.3  Responsibility of Skybird Vendors
     ---------------------------------

     Subject to the limitations set forth herein, the Skybird Vendors shall:


                                      -50-

     (a)  be liable to the Purchaser and its Additional Indemnities for all
          Indemnified Losses which any one or more of them may suffer, sustain,
          pay or incur; and

     (b)  indemnify and save harmless the Purchaser and its Additional
          Indemnities from and against all Indemnified Losses which may be
          brought against or suffered by any one or more of them or which any
          one or more of them may sustain, pay or incur;

     as a direct result of any breach by the Skybird Vendors of, or any
     inaccuracy of, any representation or warranty of the Skybird Vendors
     contained in Section 5.2.

8.4  Responsibility of Enron
     -----------------------

     Subject to the limitations set forth herein, Enron shall:

     (a)  be liable to the Purchaser and its Additional Indemnities for all
          Indemnified Losses which any one or more of them may suffer, sustain,
          pay or incur; and

     (b)  indemnify and save harmless the Purchaser and its Additional
          Indemnities from and against all Indemnified Losses which may be
          brought against or suffered by any one or more of them or which any
          one or more of them may sustain, pay or incur;

     as a direct result of any breach by Enron of, or any inaccuracy of, any
     representation or warranty of Enron contained in Section 5.4.

8.5  Responsibility of Purchaser
     ---------------------------

     Subject to the limitations set forth herein, the Purchaser and Wiser,
     jointly and severally, shall:

     (a)  be liable to the Vendors and their Additional Indemnities for all
          Indemnified Losses which any one or more of them may suffer, sustain,
          pay or incur; and

     (b)  indemnify and save harmless the Vendors and their Additional
          Indemnities from and against all Indemnified Losses which may be
          brought against or suffered by any one or more of them or which any
          one or more of them may sustain, pay or incur;

     as a direct result of:

     (c)  any breach by the Purchaser of, or any inaccuracy of, any
          representation or warranty of the Purchaser contained in Section 5.5;

     (d)  any act, omission, circumstance or other matter arising out of,
          resulting from, attributable to or connected with (whether before, on
          or after the Closing Date) the PNG Assets, Skybird or Invasion,
          including all Abandonment and Reclamation Obligations and
          Environmental Damage, except to the extent the


                                      -51-


          Vendors are liable to indemnify the Purchaser and its Additional
          Indemnitees, pursuant to Section 8.2 and 8.4 and the Skybird Vendors
          are liable to indemnify the Purchaser and its Additional Indemnitees
          pursuant to Section 8.3.

8.6  Limit on Vendors' Responsibility
     --------------------------------

     The Vendors' obligations and liability under Section 8.2 of this Agreement
     shall be subject to the following limitations:

     (a)  The obligations and liabilities of the Vendors pursuant to this
          Agreement are several and not joint, nor joint and several. Any
          liability shall be apportioned to the Vendors pro rata in accordance
          with the formula set forth in Section 2.2(b) provided that the
          aggregate liability of the Vendors under Sections 8.2 shall not, in
          any event, exceed $7,000,000.

     (b)  The Purchaser and its Additional Indemnitees shall have no remedy or
          cause of action pursuant to this Agreement in respect of any
          circumstance or other matter disclosed to or actually known to the
          Purchaser or its Affiliates or their respective directors, officers,
          servants, agents or employees as at the Closing Date.

     (c)  No Vendor shall have liability in connection with Indemnified Losses
          unless the Purchaser shall, prior to the expiry of the Survival
          Period, have provided such Vendor with a Notice of Claim.

     The above limitations and the limitation in Section 8.11(c) shall not limit
     the recourse against a Vendor with respect to a breach of Section 5.1(f)
     hereof by such Vendor.

8.7  Limit on Skybird Vendors' Responsibility
     ----------------------------------------

     The Skybird Vendors' obligations and liability under Section 8.3 of this
     Agreement shall be subject to the following limitations:

     (a)  The obligations and liabilities of the Skybird Vendors pursuant to
          this Agreement are several and not joint, nor joint and several. Each
          Skybird Vendor shall bear all obligations and liabilities of the
          Skybird Vendors in proportion to the percentage set opposite their
          name in Schedule 1.2(d), provided that the aggregate liability of the
          Skybird Vendors shall not, in any event, exceed the portion of the
          Share Consideration allocated to the Skybird Shares in accordance
          herewith.

     (b)  The Purchaser and its Additional Indemnitees shall have no remedy or
          cause of action pursuant to this Agreement in respect of any
          circumstance or other matter disclosed to or actually known to the
          Purchaser or its Affiliates or their respective directors, officers,
          servants, agents or employees as at the Closing Date.

     (c)  No Skybird Vendor shall have liability in connection with Indemnified
          Losses unless the Purchaser shall, prior to the expiry of the Survival
          Period, have provided such Skybird Vendor with a Notice of Claim.


                                      -52-

     The above limitations and the limitation in Section 8.11(c) shall not limit
     the recourse against a Skybird Vendor with respect to a breach by such
     Skybird Vendor of Section 5.2(q).

8.8  Limit on Enron's Responsibility
     --------------------------------

     Enron's obligations and liability under Section 8.4 of this Agreement shall
     be subject to the following limitations:

     (a)  the aggregate liability of Enron shall not, in any event, exceed the
          amount paid to Enron pursuant to Section 2.2(a)(ii);

     (b)  the Purchaser and its Additional Indemnitees shall have no remedy or
          cause of action pursuant to this Agreement in respect of any
          circumstance or other matter disclosed to or actually known to the
          Purchaser or its Affiliates or their respective directors, officers,
          servants, agents or employees as at the Closing Date; and

     (c)  Enron shall have no liability in connection with Indemnified Losses
          unless the Purchaser shall, prior to the expiry of the Survival
          Period, have provided Enron with a Notice of Claim.

8.9  Responsibility Extends To Legal Costs and Settlements
     -----------------------------------------------------

     Notwithstanding any provision to the contrary contained in this Article 8,
     references to costs in the liability and indemnification obligations
     prescribed by Sections 8.2, 8.3, 8.4 and 8.5 shall be deemed to include
     legal (on a solicitor-client basis) and other professional fees and
     disbursements on a full indemnity basis, and shall extend to settlements,
     satisfactions or other compromises with respect to claims by third Persons
     for Indemnified Losses.

8.10 Limitations
     -----------
     Notwithstanding anything herein to the contrary:

     (a)  the indemnities provided in Sections 8.2, 8.3, 8.4 and 8.5 shall not
          apply to the extent that claims for Indemnified Losses are reimbursed
          to the Person to be indemnified by insurance; and

     (b)  if Indemnified Losses suffered, sustained, paid or incurred by Persons
          claiming indemnity at any time before or subsequent to the making of
          an indemnity payment are reduced by any tax benefit or recovery, the
          amount of such reduction.

8.11 Limitation on Rights or Remedies
     --------------------------------

     (a)  Other than as set forth in Sections 7.3 and 7.4, this Article 8 sets
          forth the sole rights and remedies of each Party and its Additional
          Indemnities in connection with (i) the transactions contemplated
          herein, and (ii) any act, omission,


                                      -53-


          circumstance or other matter arising out of, resulting from,
          attributable to or connected with any breach of any representation,
          warranty or covenant made by any other Party, and such first mentioned
          Party and its Additional Indemnities shall have no further right or
          remedy (whether legal, equitable, fiduciary or in tort) whatsoever,
          against such other Party, or its Affiliates or their respective
          directors, officers, servants, agents, advisors or employees.

     (b)  The Purchaser acknowledges that it shall not be entitled to any rights
          or remedies as against Invasion, the Vendors, their Affiliates or
          their respective directors, officers, servants, agents and employees
          under Applicable Law, including common law or in equity, pertaining to
          any Indemnified Losses, in respect of which it is required to
          indemnify the Vendors pursuant to Section 8.5 and that it shall not be
          entitled to name former directors, officers and employees of Invasion,
          the Vendors or their Affiliates or their respective directors,
          officers, servants, agents and employees under Section 8.5 as third
          party to any action commenced by any third Person against the
          Purchaser or Invasion, as the case may be.

     (c)  The Vendors, Enron and the Skybird Vendors shall have no liability in
          connection with Indemnified Losses under this Article 8 unless the
          aggregate liability in respect of such claims for the Indemnified
          Losses is in excess of an aggregate of $500,000 which amount shall be
          fully deductible against such claims.

8.12 Procedure - Indemnities
     -----------------------

     Any Person seeking indemnification shall give reasonably prompt notice
     thereof to the Party from whom indemnification is sought.  The Party from
     whom indemnification is sought shall have the sole right to conduct, settle
     or otherwise dispose of any legal action in respect of which
     indemnification is sought in any manner it deems appropriate without the
     consent of the other party if but only if it has agreed that the matters in
     the action are indemnified pursuant to Sections 8.2, 8.3, 8.4 or 8.5.  If
     the Party from whom indemnification is sought pays the indemnified amount
     to the other Party seeking indemnification, the paying Party shall not be
     responsible for any costs described in Section 8.9 incurred after such
     payment.

8.13 No Merger of Legal Responsibilities
     -----------------------------------

     The liabilities and indemnities created in this Article 8 shall be deemed
     to apply to, and shall not merge in, all assignments, transfer and other
     documents conveying any of the Purchased Shares to the Purchaser,
     notwithstanding the terms of such assignments, transfers and other
     documents, Applicable Law or any rule of law or equity to the contrary, and
     all such rules are hereby waived.


                                      -54-

                                   ARTICLE 9
                                  ARBITRATION

9.1  Reference to Arbitration
     ------------------------

     (a)  Insofar as the Parties are unable to agree on any matter which
          expressly may be referred to arbitration hereunder, either Party may
          serve the other Party written notice that it wishes such matter be
          referred to arbitration.

     (b)  The Parties shall meet within 7 days of the receipt of a notice issued
          pursuant to Section 9.1(a) to attempt to agree on a single arbitrator
          qualified by experience, education and training, to determine such
          matter. If the Parties are unable to agree on the selection of the
          arbitrator, the Party which issued such notice shall forthwith make
          application to a judge of the Court of Queen's Bench of the Province
          of Alberta pursuant to the Arbitration Act (Alberta) for the
          appointment of a single arbitrator, and failing such action on the
          part of the Party which issued such notice, the other Party may make
          such application.

9.2  Reference to Arbitration
     ------------------------

     (a)  The arbitrator selected pursuant to Section 9.1 shall proceed as soon
          as is practicable to hear and determine the matter in dispute, and
          shall be directed to provide a written decision respecting such matter
          within 45 days of appointment. The Parties shall provide such
          assistance and information as may be reasonably necessary to enable
          the arbitrator to determine such matter.

     (b)  Except to the extent modified in this Article, the arbitrator shall
          conduct any arbitration hereunder pursuant to the provisions of the
          Arbitration Act (Alberta).

     (c)  The liability between the Parties for the payment of the compensation
          and expenses of the arbitrator shall be determined by the arbitrator.

                                  ARTICLE 10
                         WISER GUARANTEE AND ASSIGNMENT
                         ------------------------------

10.1 Guarantee
     ---------

     Wiser hereby unconditionally and irrevocably guarantees the punctual and
     complete performance by the Purchaser of all of its obligations under this
     Agreement, provided that the liability of Wiser shall not exceed the
     liability of the Purchaser hereunder.

10.2 Assignment
     ----------

     Notwithstanding Section 11.3, upon written notice to the Vendors, the
     Purchaser may assign this Agreement to an Affiliate which is resident in
     Canada, provided that Wiser confirms and acknowledges that Section 10.1
     applies to such Affiliate.


                                      -55-

                                  ARTICLE 11
                            MISCELLANEOUS PROVISIONS

11.1 Waiver Must Be In Writing
     -------------------------

     No waiver by any Party of any breach (whether actual or anticipated) of any
     of the terms, conditions, representations or warranties contained herein
     shall take effect or be binding upon that Party unless the waiver is
     expressed in writing under the authority of that Party. Any waiver so given
     shall extend only to the particular breach so waived and shall not limit or
     affect any rights with respect to any other or future breach.

11.2 Amendment
     ---------

     (a)  This Agreement may be amended only by written instrument executed by
          the Vendors and the Purchaser.

     (b)  The Parties hereto acknowledge that each of the Invasion Minority
          Shareholders and the Skybird Minority Shareholders may become Parties
          hereto by executing a signature page to this Agreement.

11.3 Assignments Before Closing
     --------------------------

     Prior to Closing, no Party may assign its interest in or under this
     Agreement without the prior written consent of the other Parties.

11.4 Service Of Notice
     -----------------

     Notwithstanding anything to the contrary contained herein, all notices
     required or permitted hereunder shall be in writing.  Any notice to be
     given hereunder shall be deemed to be served properly if served in any of
     the following modes:

     (a)  personally, by delivering the notice to the Party on which it is to be
          served at that Party's address for service. Personally served notices
          shall be deemed to be received by the addressee when actually
          delivered as aforesaid, provided that such delivery shall be during
          normal business hours on any Business Day. If a notice is not
          delivered on a Business Day or is delivered after the addressee's
          normal business hours, such notice shall be deemed to have been
          received by such Party at the commencement of the addressee's first
          Business Day next following the time of the delivery; or

     (b)  by facsimile (or by any other like method by which a written message
          may be sent) directed to the Party on which it is to be served at that
          Party's address for service. A notice so served shall be deemed to be
          received by the addressee when actually received by it, if received
          within normal business hours on any Business Day or at the
          commencement of the next ensuing Business Day following transmission
          if such notice is not received during business hours.


                                      -56-



11.5 Addresses For Notices
     ---------------------

     The address for service of notices hereunder of each of the Parties shall
     be as follows:

     ENRON CANADA CORP.:                3500 Canterra Tower
                                        400 - 3rd Avenue S.W.
                                        Calgary, Alberta
                                        T2P 4H2
                                        Attention:  Assistant General Counsel
                                        Fax:  (403) 974-6707
                                        Telephone:  (403) 974-6700

     SKYBIRD ENERGY INC.:               3000, 400 - 3rd Avenue S.W.
                                        Calgary, Alberta
                                        T2P 4H2
                                        Attention:  President
                                        Fax:  (403) 213-8277
                                        Telephone:  (403) 213-8260

     JAMES E. PAULSON:                  c/o Skybird Energy Inc.
                                        1050, 340 - 12th Avenue S.W.
                                        Calgary, Alberta  T2R 1L5
                                        Fax: (403) 266-6570
                                        Telephone: (403) 266-6794:

     MICHAEL KANOVSKY:                  c/o C2Sky Inc.
                                        3000, 400 - 3rd Avenue S.W.
                                        Calgary, Alberta
                                        T2P 4H2
                                        Fax:  (403) 213-8277
                                        Telephone:  (403) 213-8260

     INVASION MINORITY SHAREHOLDERS:    c/o Enron Canada Corp.
                                        3500 Canterra Tower
                                        400 - 3rd Avenue S.W.
                                        Calgary, Alberta
                                        T2P 4H2
                                        Attention:  Assistant General Counsel
                                        Fax:  (403) 974-6707
                                        Telephone:  (403) 974-6700



                                      -57-

     SKYBIRD MINORITY SHAREHOLDERS:      c/o Skybird Energy Inc.
                                         3000, 400 - 3rd Avenue S.W.
                                         Calgary Alberta  T2P 4H2
                                         Attention:  President
                                         Fax:  (403) 213-8277
                                         Telephone:  (403) 213-8260

     PURCHASER:                          The Wiser Oil Company of Canada
                                         2500, 645 - 7th Avenue S.W.
                                         Calgary, Alberta
                                         T2P 4G8
                                         Fax:  (403) 269-6976
                                         Telephone:  (403) 237-9550

     WISER:                              The Wiser Oil Company
                                         8115 Preston Road, Suite 400
                                         Dallas, Texas  75225
                                         Attention:  President
                                         Fax:  (214) 373-3610
                                         Telephone:  (214) 265-0080

     YELLOWBIRD:                         1050, 340 - 12th Avenue S.W.
                                         Calgary, Alberta
                                         T2R 1L5
                                         Attention: President
                                         Fax: (403) 266-6570
                                         Telephone: (403) 266-6794

     C2SKY:                              3000, 400 - 3rd Avenue S.W.
                                         Calgary, Alberta
                                         T2P 4H2
                                         Attention:  President
                                         Fax:  (403) 213-8277
                                         Telephone:  (403) 213-8260


     A Party may change its address for service by notice to the other Party,
     and such changed address for service thereafter shall be effective for all
     purposes of this Agreement.

11.6 Costs and Expenses
     ------------------

     Except as specifically provided herein, all legal and other costs and
     expenses in connection with this Agreement and the transactions
     contemplated hereby shall be paid by the Party which incurred the same.
     Notwithstanding the foregoing, the Vendors acknowledge and agree that the
     Share Consideration and any adjustment payment under Section 2.3(j) will be
     reduced by the total costs and expenses, including legal, accounting


                                      -58-

     and tax consulting fees and expenses, incurred by the Requisite
     Shareholders on behalf of the Vendors in connection with this Agreement.

11.7 Further Assurances
     ------------------

     At the Closing Date and thereafter as may be necessary, the Parties shall
     execute, acknowledge and deliver such instruments and take such other
     actions as may be reasonably necessary to fulfil their respective
     obligations under this Agreement, including with respect to Enron, on
     request of the Purchaser, the execution of any transfers or discharges of
     the Security Interests with respect to the Enron Debt.

11.8 Governing Law; Attornment; Etc.
     -------------------------------

     (a)  This Agreement and all such documents executed in connection with this
          agreement and the transactions contemplated hereby shall be governed
          by, and construed and enforced in accordance with the applicable laws,
          other than conflict of laws rules, prevailing in the Province of
          Alberta.

     (b)  The Parties irrevocably:

          (i)    submit and attorn to the non-exclusive jurisdiction of the
                 Courts of the Province of Alberta for all matters arising out
                 of or relating to this Agreement, or any of the transactions
                 contemplated hereby except that the Parties irrevocably submit
                 and attorn to the non-exclusive jurisdiction of the Courts of
                 the Province of Alberta for such matters arising out of or
                 relating to documentation specifically made to be governed by
                 the terms of the applicable laws of the Province of Alberta
                 pursuant to Section 11.8(a);

          (ii)   waive all right to object to jurisdiction of such Courts in any
                 legal action or proceeding relative to this Agreement or the
                 transactions contemplated hereby or execution of any judgment,
                 order or decree issued in or as a result of any such action,
                 suit or proceeding which they may now or hereafter have by
                 reason of domicile or otherwise;

          (iii)  waive any objection to the laying of venue in such Courts of
                 any of the aforesaid actions, suits or proceedings arising out
                 of or in connection with this Agreement or the transactions
                 contemplated hereby;

          (iv)   waive and agree not to plead or claim that any action, suit or
                 proceeding in such Courts has been brought in an inconvenient
                 forum; and

          (v)    waive any right they may have to, or to apply for, trial by
                 jury in connection with any matter, action, proceeding, claim
                 or counterclaim arising out of or relating to this Agreement or
                 any of the transactions contemplated hereby.


                                      -59-

11.9  Invalidity of Provisions
      ------------------------

      If any of the provisions of this Agreement are determined to be invalid,
      illegal or unenforceable in any respect, the validity, legality or
      enforceability of the remaining provisions shall not in any way be
      affected or impaired thereby.

11.10 Time
      ----

      Time shall be of the essence in this Agreement.

11.11 Supersedes Earlier Agreements
      -----------------------------

      Other than the Confidentiality Agreement, this Agreement constitutes the
      entire agreement between the Parties relating to the subject-matter
      hereof; and there are no collateral or other statements, understandings,
      covenants, agreements, representations or warranties, written or oral,
      relating to the subject-matter hereof. This Agreement supersedes all prior
      agreements, understandings, negotiations and discussions, whether oral or
      written, between the Parties or their predecessors relating to the
      subject-matter of this Agreement, including the Letter Agreement.


                                      -60-


11.12 Enurement
      ---------

      This Agreement shall be binding upon and enure to the benefit of the
      Parties and their respective successors and permitted assigns.

11.13 Counterpart Execution
      ---------------------

      This Agreement and any document or instrument to be executed and delivered
      by the Parties hereunder or in connection herewith may be executed and
      delivered in separate counterparts and delivered by one Party to the other
      by facsimile, each of which when so executed and delivered shall be deemed
      an original and all such executed counterparts shall together constitute
      one and the same agreement. If this Agreement or any such document or
      instrument is delivered by facsimile, the Party so delivering this
      Agreement or such document or instrument shall within a reasonable time
      after such delivery deliver an original executed copy to the other.

      IN WITNESS WHEREOF the Parties have duly executed this Agreement.


                                         ENRON CANADA CORP.


                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:

                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:


                                         SKYBIRD ENERGY INC.



                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:

                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:


                                      -61-

                                         C2SKY INC.


                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:

                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:




   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -62-

- -----------------------------           -------------------------------
Witness                                 JAMES E. PAULSON





   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -63-

- -----------------------------           -------------------------------
Witness                                 MICHAEL KANOVSKY





   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -64-

                                             EVOLVE MANAGEMENT INC.


                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:

                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:



   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -65-

                                         YELLOWBIRD PRODUCTS LIMITED


                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:

                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:



   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -66-



                                         THE WISER OIL COMPANY



                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:

                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:



                                         THE WISER OIL COMPANY OF CANADA



                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:

                                         PER:
                                             -------------------------------
                                             Name:
                                             Title:


   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -67-

                 Minority Shareholders of Invasion and Skybird
                 ---------------------------------------------



- -----------------------------           -------------------------------
Witness                                 CAROLINE BANKS




- -----------------------------           -------------------------------
Witness                                 RICHARD BROWN




- -----------------------------           -------------------------------
Witness                                 ROBIN CHAN




- -----------------------------           -------------------------------
Witness                                 DARRELL DENNEY




- -----------------------------           -------------------------------
Witness                                 CHRISTOPHER DINGLE




- -----------------------------           -------------------------------
Witness                                 DANIEL FOURNIER




- -----------------------------           -------------------------------
Witness                                 WALLACE SHAW




- -----------------------------           -------------------------------
Witness                                 JAMES BANNISTER


   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -68-

           Minority Shareholders of Invasion and Skybird (Continued)
           ---------------------------------------------------------




- -----------------------------           -------------------------------
Witness                                 GERALD DEYELL




- -----------------------------           -------------------------------
Witness                                 JONI PAULUS




- -----------------------------           -------------------------------
Witness                                 MUNGO HARDWICKE-BROWN




- -----------------------------           -------------------------------
Witness                                 BRAD HURTUBISE




- -----------------------------           -------------------------------
Witness                                 WILLIAM JAMES




- -----------------------------           -------------------------------
Witness                                 DONNA KANOVSKY




- -----------------------------           -------------------------------
Witness                                 JOE LADOUCEUR




- -----------------------------           -------------------------------
Witness                                 MADELYN LANG


   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -69-

           Minority Shareholders of Invasion and Skybird (Continued)
           ---------------------------------------------------------




- -----------------------------           -------------------------------
Witness                                 MICHAEL LANG



- -----------------------------           -------------------------------
Witness                                 ANGELA LAU



- -----------------------------           -------------------------------
Witness                                 BILL MACDONALD



- -----------------------------           -------------------------------
Witness                                 RICCARDO NARDELLI



- -----------------------------           -------------------------------
Witness                                 PETER PAULSON



- -----------------------------           -------------------------------
Witness                                 HERB PINDER



- -----------------------------           -------------------------------
Witness                                 MADELEINE PINDER



- -----------------------------           -------------------------------
Witness                                 ROBERT ROONEY



   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -70-

           Minority Shareholders of Invasion and Skybird (Continued)
           ---------------------------------------------------------




- -----------------------------           -------------------------------
Witness                                 CARL SCHNARE




- -----------------------------           -------------------------------
Witness                                 PAUL SPARKS


B.D.A. INVESTMENT CORP.                 DRS RESOURCES


PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:

PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:




DRS RESOURCE INVESTMENT LTD.            KANOVSKY CHILDREN FAMILY TRUST



PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:

PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:



   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -71-

           Minority Shareholders of Invasion and Skybird (Continued)
           ---------------------------------------------------------

NBC TECHNOLOGIES INC.                   NOVA BANCORP INVESTMENTS LTD.


PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:

PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:


ROCKHILL RESOURCES                      RUNNYMEDE RESOURCES CORPORATION


PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:

PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:


RWFT HOLDINGS LTD.                      SIREN CAPITAL CORP.



PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:

PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:


   This is an execution page to a share purchase agreement dated May 4, 2001


                                      -72-

           Minority Shareholders of Invasion and Skybird (Continued)
           ---------------------------------------------------------


SKY ENERGY CORPORATION                  CULSHAW PETROLEUM SERVICES INC.



PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:

PER:                                    PER:
    -------------------------------         -------------------------------
    Name:                                   Name:
    Title:                                  Title:



   This is an execution page to a share purchase agreement dated May 4, 2001


                                SCHEDULE 1.2(a)

                                 LAND SCHEDULE
                                 -------------


Available upon request from Invasion Energy Inc.


                                SCHEDULE 1.2(b)

                             LIST OF SHAREHOLDERS
                             --------------------

Class B Invasion Shares
- -----------------------




                                                              Percentage of Total         Allocation
Name                                Total Class B Shares         Class B Shares           Percentage
- -----------------------------------------------------------------------------------------------------
                                                                               
Enron Canada Corp.                         6,291,380                   48.93%                  71.857%
- -----------------------------------------------------------------------------------------------------
Skybird Energy Inc.                        4,102,504                   31.91%                       0%
- -----------------------------------------------------------------------------------------------------
Yellowbird Products Limited                  404,818                    3.15%                   4.624%
- -----------------------------------------------------------------------------------------------------
Sky Energy Corporation                       296,895                    2.31%                   3.391%
- -----------------------------------------------------------------------------------------------------
Richard Brown                                227,227                    1.77%                   2.595%
- -----------------------------------------------------------------------------------------------------
Siren Capital Corp.                          183,743                    1.43%                   2.098%
- -----------------------------------------------------------------------------------------------------
Caroline Banks                               175,000                    1.36%                   1.999%
- -----------------------------------------------------------------------------------------------------
Daniel Fournier                              110,097                    0.86%                   1.257%
- -----------------------------------------------------------------------------------------------------
Wallace Shaw                                  17,669                    0.14%                   0.202%
- -----------------------------------------------------------------------------------------------------
James Bannister                               10,097                    0.08%                   0.115%
- -----------------------------------------------------------------------------------------------------
Gerald Deyell                                  5,048                    0.04%                   0.058%
- -----------------------------------------------------------------------------------------------------
Joni Paulus                                    5,048                    0.04%                   0.058%
- -----------------------------------------------------------------------------------------------------
Mungo Hardwicke-Brown                          2,524                    0.02%                   0.029%
- -----------------------------------------------------------------------------------------------------
Robert Rooney                                150,000                    1.17%                   1.713%
- -----------------------------------------------------------------------------------------------------
C2 Sky Inc.                                  148,593                    1.16%                   1.697%
- -----------------------------------------------------------------------------------------------------
Rockhill Resources                           147,227                    1.15%                   1.682%
- -----------------------------------------------------------------------------------------------------
DRS Resources                                105,383                    0.82%                   1.204%
- -----------------------------------------------------------------------------------------------------
Michael Lang                                 100,000                    0.78%                   1.142%
- -----------------------------------------------------------------------------------------------------
Darrell Denney (RRSP)                        100,000                    0.76%                   1.142%
- -----------------------------------------------------------------------------------------------------
Bill Macdonald                                50,000                    0.39%                   0.571%
- -----------------------------------------------------------------------------------------------------
Brad Hurtubise                                48,000                    0.37%                   0.548%
- -----------------------------------------------------------------------------------------------------
Madelyn Lang                                  47,227                    0.37%                   0.539%
- -----------------------------------------------------------------------------------------------------
Christopher Dingle                            40,670                    0.32%                   0.465%
- -----------------------------------------------------------------------------------------------------
NBC Technologies Inc.                         32,227                    0.25%                   0.368%
- -----------------------------------------------------------------------------------------------------
Joe Ladouceur (RRSP)                          20,095                    0.16%                   0.230%
- -----------------------------------------------------------------------------------------------------
Culshaw Petroleum Services Inc.               15,000                    0.12%                   0.171%
- -----------------------------------------------------------------------------------------------------
Angela Lau                                    10,064                    0.08%                   0.115%
- -----------------------------------------------------------------------------------------------------
Paul Sparks                                    9,446                    0.07%                   0.108%
- -----------------------------------------------------------------------------------------------------
Robin Chan                                     1,890                    0.01%                   0.022%
- -----------------------------------------------------------------------------------------------------
TOTAL                                     12,857,872                  100.00%                 100.000%
- -----------------------------------------------------------------------------------------------------




                                SCHEDULE 1.2(c)

Class C Invasion Shares
- -----------------------



Name                              Total Class C Shares         Allocation Percentage
- ------------------------------------------------------------------------------------
                                                        
Richard Brown                              99                                  58.93%
- ------------------------------------------------------------------------------------
Darrell Denney                             33                                  19.64%
- ------------------------------------------------------------------------------------
Joe Ladouceur                              21                                  12.50%
- ------------------------------------------------------------------------------------
Carl Schnare                               12                                   7.14%
- ------------------------------------------------------------------------------------
Robin Chan                                  3                                   1.79%
- ------------------------------------------------------------------------------------
TOTAL                                     168                                 100.00%
- ------------------------------------------------------------------------------------




                                SCHEDULE 1.2(d)

Skybird Common Shares
- ---------------------


Name                                       Total Common Shares     Allocation Amount
- ------------------------------------------------------------------------------------
                                                             
Jamie Paulson                                      741                         17.61%
- ------------------------------------------------------------------------------------
Peter Paulson                                      741                         17.61%
- ------------------------------------------------------------------------------------
C2Sky Inc.                                         729                         17.33%
- ------------------------------------------------------------------------------------
DRS Resource Investment Ltd.                       423                         10.05%
- ------------------------------------------------------------------------------------
Donna Kanovsky                                     403                          9.57%
- ------------------------------------------------------------------------------------
Kanovsky Children Family Trust                     350                          8.32%
- ------------------------------------------------------------------------------------
Riccardo Nardelli                                  250                          5.94%
- ------------------------------------------------------------------------------------
Runnymede Resources Corporation                    200                          4.75%
- ------------------------------------------------------------------------------------
Nova Bancorp Investments Ltd.                       50                          1.19%
- ------------------------------------------------------------------------------------
Nova Bancorp Securities Ltd.                        50                          1.19%
- ------------------------------------------------------------------------------------
RWFT Holdings Ltd.                                 100                          2.38%
- ------------------------------------------------------------------------------------
Madeleine Pinder                                    75                          1.78%
- ------------------------------------------------------------------------------------
Angela Lau                                          60                          1.45%
- ------------------------------------------------------------------------------------
Bill James                                          35                          0.83%
- ------------------------------------------------------------------------------------
TOTAL                                            4,207                           100%
- ------------------------------------------------------------------------------------


Skybird Preferred Shares
- ------------------------


Name                                          Total Preferred Shares      Allocation Amount
- --------------------------------------------------------------------------------------------
                                                                   
Yellowbird Products Limited                          1,481,887                    $1,481,887
- --------------------------------------------------------------------------------------------
Michael Kanovsky                                       729,387                    $  729,387
- --------------------------------------------------------------------------------------------
DRS Resource Investment Ltd.                           422,926                    $  422,926
- --------------------------------------------------------------------------------------------
Donna Kanovsky                                         402,500                    $  402,500
- --------------------------------------------------------------------------------------------
Kanovsky Children Family Trust                         350,000                    $  350,000
- --------------------------------------------------------------------------------------------
B.D.A. Investment Corp.                                250,000                    $  250,000
- --------------------------------------------------------------------------------------------
Runnymede Resources Corporation                        200,000                    $  200,000
- --------------------------------------------------------------------------------------------
Nova Bancorp Investments Ltd.                           50,000                    $   50,000
- --------------------------------------------------------------------------------------------
Nova Bancorp Securities Ltd.                            50,000                    $   50,000
- --------------------------------------------------------------------------------------------
RWFT Holdings Ltd.                                     100,000                    $  100,000
- --------------------------------------------------------------------------------------------
Angela Lau                                              60,803                    $   60,803
- --------------------------------------------------------------------------------------------
Madeleine Pinder                                        52,500                    $   52,500
- --------------------------------------------------------------------------------------------
Bill James                                              35,000                    $   35,000
- --------------------------------------------------------------------------------------------
Herb Pinder                                             22,500                    $   22,500
- --------------------------------------------------------------------------------------------
TOTAL                                                4,207,503                    $4,207,503
- --------------------------------------------------------------------------------------------


The Skybird Vendors acknowledge and agree that after the allocation to the
Skybird Preferred Shares, any remaining amount shall be allocated to the Skybird
Common Shares in accordance with the above allocation.  For certainty, if some
of the Skybird Preferred Shares are redeemed as permitted under Section 4.3, the
allocation amounts for the Skybird Preferred Shares above shall be adjusted for
such redemption on the basis of $1 per Skybird Preferred Share redeemed.


                                SCHEDULE 1.2(e)

                         EFFECTIVE DATE BALANCE SHEET
                         ----------------------------



                                SCHEDULE 1.2(f)

                         INVASION FINANCIAL STATEMENTS
                         -----------------------------



                                SCHEDULE 1.2(g)

                         SKYBIRD FINANCIAL STATEMENTS
                         ----------------------------



                                SCHEDULE 5.1(p)

                   DISCLOSURE RE: CONTRACTS AND COMMITMENTS
                   ----------------------------------------

1.   Contract Operating Agreement dated August 29, 2000 between Invasion Energy
     Inc. and Accutech Oilfield Services
2.   Equipment Rental Agreement dated December 11, 2000 between Invasion Energy
     Inc. and Energy Industries Inc.
3.   Equipment Rental Agreement dated December 30, 1999 between Invasion Energy
     Inc. and Collicutt Hanover Compression Co.
4.   Equipment Rental Agreement dated December 30, 1999 between Invasion Energy
     Inc. and Collicutt Hanover Compression Co.
5.   Gas Management Services Agreement dated November 1, 2000 between Invasion
     Energy Inc. and Enron Canada Corp.
6.   Notification of Gas Services Agreement dated October 26, 1999 between
     Invasion Energy Inc. and Enron Canada Corp.
7.   Firm Gas Purchase/Sale Agreement dated November 2, 1999 between Invasion
     Energy Inc. and Enron Canada Corp.
8.   Schedule "A" to the Firm Gas Purchase/Sale Agreement dated April 27, 2001
     between Invasion Energy Inc. and Enron Canada Corp.
9.   Sale & Purchase of Natural Gas Agreement (#QU5599.1) dated March 1, 2001
     between Invasion Energy Inc. and Enron Canada Corp.
10.  Amendment to Sale & Purchase of Natural Gas Agreement (#QU5599.1) dated
     March 28, 2001 between Invasion Energy Inc. and Enron Canada Corp.
11.  Amendment to Sale & Purchase of Natural Gas Agreement (#QU5599.1/2/3) dated
     April 2, 2001 between Invasion Energy Inc. and Enron Canada Corp.
12.  Amendment to Sale & Purchase of Natural Gas Agreement (#QU5599.1/2/3/4/5)
     dated May 3, 2001 between Invasion Energy Inc. and Enron Canada Corp.
13.  Sale & Purchase of Natural Gas Agreement (#QU5884.1) dated March 5, 2001
     between Invasion Energy Inc. and Enron Canada Corp.
14.  Sale & Purchase of Natural Gas Agreement (#QU5884.2) dated March 5, 2001
     between Invasion Energy Inc. and Enron Canada Corp.
15.  Sale & Purchase of Natural Gas Agreement (#QQ0778.1) dated February 8, 2001
     between Invasion Energy Inc. and Enron Canada Corp.
16.  Sale & Purchase of Natural Gas Agreement (#QQ0778.2) dated February 8, 2001
     between Invasion Energy Inc. and Enron Canada Corp.
17.  Multi-Energy Insurance Package - Policy No. MEP1145 effective September 15,
     2000 for a one-year term through Aon Reed Stenhouse Inc.


                                      -2-

18.  Non-Owned Aircraft Liability Insurance - Policy No. ALN009051 effective
     September 15, 2000 for a one-year term through Aon Reed Stenhouse Inc.
19.  Master Agreement for the Assignment of Service dated October 26, 1999
     between Invasion Energy Inc. and Nova Gas Transmission Ltd.


                               TABLE OF CONTENTS



                                                                                      Page
                                                                                    
ARTICLE 1 DEFINITIONS AND SCHEDULES...................................................   3
     1.1       Definitions............................................................   3
     1.2       Schedules..............................................................  14
     1.3       References and Headings................................................  14
     1.4       Singular/Plural; Derivatives...........................................  15
     1.5       Statutory References...................................................  15
     1.6       Conflicts..............................................................  15
     1.7       Accounting References..................................................  15
     1.8       Vendor's Knowledge.....................................................  15
ARTICLE 2 PURCHASE AND SALE...........................................................  16
     2.1       Purchase and Sale......................................................  16
     2.2       Payment of Purchase Price..............................................  16
     2.3       Adjustments to Portion of Purchase Price Allocated to Invasion Shares..  17
     2.4       Deposit................................................................  20
     2.5       Payment of Purchase Price..............................................  20
     2.6       Withholding Tax........................................................  20
     2.7       Manner of Payment......................................................  20
ARTICLE 3 CLOSING.....................................................................  20
     3.1       Place and Closing Date.................................................  20
     3.2       Effective Date of Transfer.............................................  21
     3.3       Deliveries at Closing..................................................  21
ARTICLE 4 INTERIM PERIOD..............................................................  24
     4.1       Access.................................................................  24
     4.2       Maintenance of Business and PNG Assets.................................  25
     4.3       Certain Changes Restricted.............................................  25
     4.4       Dealings or Operations re PNG Assets...................................  27
     4.5       Proposals for Dealings or Operations re PNG Assets.....................  27
     4.6       Prohibited Negotiations................................................  29
     4.7       Pre-Closing Events.....................................................  29
     4.8       Insurance..............................................................  29
ARTICLE 5 REPRESENTATIONS AND WARRANTIES OF PARTIES...................................  30
     5.1       Vendors' Representations and Warranties................................  30
     5.2       Skybird Vendors' Representations and Warranties........................  32
     5.3       Representations and Warranties of Manager..............................  34
     5.4       Representations and Warranties of Enron................................  40
     5.5       Purchaser's Representations And Warranties.............................  40
     5.6       Survival Of Representations And Warranties.............................  42
     5.7       No Additional Representations or Warranties............................  42
     5.8       No Merger..............................................................  43



                                     -ii-


                                                                                    
ARTICLE 6 CONDITIONS TO CLOSING.......................................................  43
     6.1       Conditions to the Obligations of the Purchaser to Close................  43
     6.2       Conditions to Obligations of Enron and Vendors to Close................  45
     6.3       Parties To Exercise Diligence With Respect To Conditions, etc..........  46
     6.4       Waiver of Conditions...................................................  46
     6.5       Failure To Satisfy Conditions..........................................  47
ARTICLE 7 TERMINATION.................................................................  47
     7.1       Grounds for Termination................................................  47
     7.2       Effect of Termination..................................................  47
     7.3       Entitlement to Deposit on Termination..................................  48
     7.4       Remedy for Failure to Tender...........................................  48
ARTICLE 8 LIABILITY AND INDEMNIFICATION...............................................  49
     8.1       Defined Terms..........................................................  49
     8.2       Responsibility of Vendors..............................................  49
     8.3       Responsibility of Skybird Vendors......................................  49
     8.4       Responsibility of Enron................................................  50
     8.5       Responsibility of Purchaser............................................  50
     8.6       Limit on Vendors' Responsibility.......................................  51
     8.7       Limit on Skybird Vendors' Responsibility...............................  51
     8.8       Limit on Enron's Responsibility........................................  52
     8.9       Responsibility Extends To Legal Costs and Settlements..................  52
     8.10      Limitations............................................................  52
     8.11      Limitation on Rights or Remedies.......................................  52
     8.12      Procedure - Indemnities................................................  53
     8.13      No Merger of Legal Responsibilities....................................  53
ARTICLE 9 ARBITRATION.................................................................  54
     9.1       Reference to Arbitration...............................................  54
     9.2       Reference to Arbitration...............................................  54
ARTICLE 10 WISER GUARANTEE AND ASSIGNMENT.............................................  54
     10.1      Guarantee..............................................................  54
     10.2      Assignment.............................................................  54
ARTICLE 11 MISCELLANEOUS PROVISIONS...................................................  55
     11.1      Waiver Must Be In Writing..............................................  55
     11.2      Amendment..............................................................  55
     11.3      Assignments Before Closing.............................................  55
     11.4      Service Of Notice......................................................  55
     11.5      Addresses For Notices..................................................  56
     11.6      Costs and Expenses.....................................................  57
     11.7      Further Assurances.....................................................  58
     11.8      Governing Law; Attornment; Etc.........................................  58
     11.9      Invalidity of Provisions...............................................  59



                                     -iii-


                                                                                    
     11.10     Time...................................................................  59
     11.11     Supersedes Earlier Agreements..........................................  59
     11.12     Enurement..............................................................  60
     11.13     Counterpart Execution..................................................  60