EXHIBIT 4.2

                                  $150,000,000

                           ENCORE ACQUISITION COMPANY

                    8 3/8% SENIOR SUBORDINATED NOTES DUE 2012

                          REGISTRATION RIGHTS AGREEMENT

                                                                   June 19, 2002

Credit Suisse First Boston Corporation
Deutsche Bank Securities Inc.
Fleet Securities, Inc.
Goldman, Sachs & Co.
Wachovia Securities, Inc.
BNP Paribas Securities Corp.
Fortis Investment Services LLC
Comerica Securities, Inc.
Frost Securities, Inc.
c/o Credit Suisse First Boston Corporation
   Eleven Madison Avenue
   New York, New York 10010-3629

Dear Sirs:

      Encore Acquisition Company, a Delaware corporation (the "ISSUER"),
proposes to issue and sell to Credit Suisse First Boston Corporation, Deutsche
Bank Securities, Fleet Securities, Inc., Goldman, Sachs & Co., Wachovia
Securities, Inc., BNP Paribas Securities Corp., Fortis Investment Services LLC,
Comerica Securities, Inc. and Frost Securities, Inc. (collectively, the "INITIAL
PURCHASERS"), upon the terms set forth in a purchase agreement of even date
herewith (the "PURCHASE AGREEMENT"), $150,000,000 aggregate principal amount of
its 8 3/8% Senior Subordinated Notes due 2012 (the "INITIAL SECURITIES") to be
guaranteed (the "GUARANTIES") by the subsidiaries of the Company listed on the
signature pages hereto (the "GUARANTORS" and, collectively with the Issuer, the
"COMPANY"). The Initial Securities will be issued pursuant to an Indenture,
dated as of June 25, 2002 (the "Indenture"), among the Company, the Guarantors
named therein and Wells Fargo Bank, N.A, as trustee (the "TRUSTEE"). As an
inducement to the Initial Purchasers to enter into the Purchase Agreement, the
Company agrees with the Initial Purchasers, for the benefit of the Initial
Purchasers and the holders of the Securities (as defined below) (collectively
the "HOLDERS"), as follows:

      1. Registered Exchange Offer. Unless not permitted by applicable law
(after the Company has complied with the ultimate paragraph of this Section 1),
the Company shall prepare and, not later than 90 days (such 90th day being a
"FILING DEADLINE") after the date on which the Initial Purchasers purchase the
Initial Securities pursuant to the Purchase Agreement (the "CLOSING Date"), file
with the Securities and Exchange Commission (the "COMMISSION") a registration
statement (the "EXCHANGE OFFER REGISTRATION STATEMENT") on an appropriate form
under the Securities Act of 1933, as amended (the "SECURITIES ACT"), with
respect to a proposed offer (the "REGISTERED EXCHANGE OFFER") to the Holders of
Transfer Restricted Securities (as defined in Section 6 hereof), who are not
prohibited by any law or policy of the Commission from participating in the
Registered Exchange Offer, to issue and deliver to such Holders, in exchange for
the Initial Securities, a like aggregate principal amount of debt securities of
the Company issued under the Indenture, identical in all material respects to
the Initial Securities and registered under the Securities Act (the "EXCHANGE
SECURITIES"). The Company shall use its reasonable best efforts


to (i) cause such Exchange Offer Registration Statement to become effective
under the Securities Act within 180 days after the Closing Date (such 180th day
being an "EFFECTIVENESS DEADLINE") and (ii) keep the Exchange Offer Registration
Statement effective for not less than 30 days (or longer, if required by
applicable law) after the date notice of the Registered Exchange Offer is mailed
to the Holders (such period being called the "EXCHANGE OFFER REGISTRATION
PERIOD").

      If the Company commences the Registered Exchange Offer, the Company (i)
will be entitled to consummate the Registered Exchange Offer 30 days after such
commencement (provided that the Company has accepted all the Initial Securities
theretofore validly tendered in accordance with the terms of the Registered
Exchange Offer) and (ii) will be required to consummate the Registered Exchange
Offer as soon as practicable after the date on which the Exchange Offer
Registration Statement is declared effective (the "CONSUMMATION DEADLINE").

      Following the declaration of the effectiveness of the Exchange Offer
Registration Statement, the Company shall promptly commence the Registered
Exchange Offer, it being the objective of such Registered Exchange Offer to
enable each Holder of Transfer Restricted Securities electing to exchange the
Initial Securities for Exchange Securities (assuming that such Holder is not an
affiliate of the Company within the meaning of the Securities Act, acquires the
Exchange Securities in the ordinary course of such Holder's business and has no
arrangements with any person to participate in the distribution of the Exchange
Securities and is not prohibited by any law or policy of the Commission from
participating in the Registered Exchange Offer) to trade such Exchange
Securities from and after their receipt without any limitations or restrictions
under the Securities Act and without material restrictions under the securities
laws of the several states of the United States.

      The Company acknowledges that, pursuant to current interpretations by the
Commission's staff of Section 5 of the Securities Act, in the absence of an
applicable exemption therefrom, (i) each Holder which is a broker-dealer
electing to exchange Initial Securities, acquired for its own account as a
result of market making activities or other trading activities, for Exchange
Securities (an "EXCHANGING DEALER"), is required to deliver a prospectus
containing the information set forth in (a) Annex A hereto on the cover, (b)
Annex B hereto in the "Exchange Offer Procedures" section and the "Purpose of
the Exchange Offer" section, and (c) Annex C hereto in the "Plan of
Distribution" section of such prospectus in connection with a sale of any such
Exchange Securities received by such Exchanging Dealer pursuant to the
Registered Exchange Offer and (ii) an Initial Purchaser that elects to sell
Securities (as defined below) acquired in exchange for Initial Securities
constituting any portion of an unsold allotment, is required to deliver a
prospectus containing the information required by Items 507 or 508 of Regulation
S-K under the Securities Act, as applicable, in connection with such sale.

      The Company shall use its reasonable best efforts to keep the Exchange
Offer Registration Statement effective and to amend and supplement the
prospectus contained therein, in order to permit such prospectus to be lawfully
delivered by all persons subject to the prospectus delivery requirements of the
Securities Act for such period of time as such persons must comply with such
requirements in order to resell the Exchange Securities; provided, however, that
(i) in the case where such prospectus and any amendment or supplement thereto
must be delivered by an Exchanging Dealer or an Initial Purchaser, such period
shall be the lesser of 180 days and the date on which all Exchanging Dealers and
the Initial Purchasers have sold all Exchange Securities held by them (unless
such period is extended pursuant to Section 3(j) below) and (ii) the Company
shall make such prospectus and any amendment or supplement thereto available to
any broker-dealer for use in connection with any resale of any Exchange
Securities for a period of not less than 180-days after the consummation of the
Registered Exchange Offer.

      If, upon consummation of the Registered Exchange Offer, any Initial
Purchaser holds Initial Securities acquired by it as part of its initial
distribution, the Company, simultaneously with the delivery of the Exchange
Securities pursuant to the Registered Exchange Offer, shall issue and deliver to
such Initial Purchaser upon the written request of such Initial Purchaser, in
exchange (the "PRIVATE EXCHANGE") for the Initial Securities held by such
Initial Purchaser, a like principal amount of debt securities of the Company
issued under the Indenture and identical in all material respects to the Initial
Securities (the "PRIVATE EXCHANGE SECURITIES"). The Initial Securities, the
Exchange Securities and the Private Exchange Securities are herein collectively
called the "Securities".


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      In connection with the Registered Exchange Offer, the Company shall:

            (a) mail to each Holder a copy of the prospectus forming part of the
      Exchange Offer Registration Statement, together with an appropriate letter
      of transmittal and related documents;

            (b) keep the Registered Exchange Offer open for not less than 30
      days (or longer, if required by applicable law) after the date notice
      thereof is mailed to the Holders;

            (c) utilize the services of a depositary for the Registered Exchange
      Offer with an address in the Borough of Manhattan, The City of New York,
      which may be the Trustee or an affiliate of the Trustee;

            (d) permit Holders to withdraw tendered Securities at any time prior
      to the close of business, New York time, on the last business day on which
      the Registered Exchange Offer shall remain open; and

            (e) otherwise comply with all applicable laws.

      As soon as practicable after the close of the Registered Exchange Offer or
the Private Exchange, as the case may be, the Company shall:

            (x) accept for exchange all the Securities validly tendered and not
      withdrawn pursuant to the Registered Exchange Offer and the Private
      Exchange;

            (y) deliver to the Trustee for cancellation all the Initial
      Securities so accepted for exchange; and

            (z) cause the Trustee to authenticate and deliver promptly to each
      Holder of the Initial Securities, Exchange Securities or Private Exchange
      Securities, as the case may be, equal in principal amount to the Initial
      Securities of such Holder so accepted for exchange.

      The Indenture will provide that the Exchange Securities will not be
subject to the transfer restrictions set forth in the Indenture and that all the
Securities will vote and consent together on all matters as one class and that
none of the Securities will have the right to vote or consent as a class
separate from one another on any matter.

      Interest on each Exchange Security and Private Exchange Security issued
pursuant to the Registered Exchange Offer and in the Private Exchange will
accrue from the last interest payment date on which interest was paid on the
Initial Securities surrendered in exchange therefor or, if no interest has been
paid on the Initial Securities, from the date of original issue of the Initial
Securities.

      Each Holder participating in the Registered Exchange Offer shall be
required to represent to the Company that at the time of the consummation of the
Registered Exchange Offer (i) any Exchange Securities received by such Holder
will be acquired in the ordinary course of business, (ii) such Holder will have
no arrangements or understanding with any person to participate in the
distribution of the Initial Securities or the Exchange Securities within the
meaning of the Securities Act, (iii) such Holder is not an "affiliate," as
defined in Rule 405 of the Securities Act, of the Company or if it is an
affiliate, such Holder will comply with the registration and prospectus delivery
requirements of the Securities Act to the extent applicable, (iv) if such Holder
is not a broker-dealer, that it is not engaged in, and does not intend to engage
in, the distribution of the Exchange Securities and (v) if such Holder is a
broker-dealer, that it will receive Exchange Securities for its own account in
exchange for Initial Securities that were acquired as a result of market-making
activities or other trading activities and that it will be required to
acknowledge that it will deliver a prospectus in connection with any resale of
such Exchange Securities.

      Notwithstanding any other provisions hereof, the Company will ensure that
(i) any Exchange Offer Registration Statement and any amendment thereto and any
prospectus forming part thereof and any supplement thereto complies in all
material respects with the Securities Act and the rules and regulations
thereunder, (ii) any Exchange Offer Registration Statement and any amendment
thereto does not, when it becomes effective, contain an untrue statement of a
material fact or omit to state a material fact required to be stated therein or
necessary to make the statements therein not misleading and (iii) any prospectus
forming part of any Exchange Offer Registration


                                       3


Statement, and any supplement to such prospectus, does not include an untrue
statement of a material fact or omit to state a material fact required to be
stated therein or necessary in order to make the statements therein, in the
light of the circumstances under which they were made, not misleading.

      If following the date hereof there has been announced a change in
Commission policy with respect to exchange offers that in the reasonable opinion
of counsel to the Company raises a substantial question as to whether the
Registered Exchange Offer is permitted by applicable federal law, the Company
will seek a no-action letter or other favorable decision from the Commission
allowing the Company to consummate the Registered Exchange Offer. The Company
will pursue the issuance of such a decision to the Commission staff level. In
connection with the foregoing, the Company will take all such other actions as
may be requested by the Commission or otherwise required in connection with the
issuance of such decision, including without limitation (i) participating in
telephonic conferences with the Commission, (ii) delivering to the Commission
staff an analysis prepared by counsel to the Company setting forth the legal
bases, if any, upon which such counsel has concluded that the Registered
Exchange Offer should be permitted and (iii) diligently pursuing a resolution
(which need not be favorable) by the Commission staff.

      2. Shelf Registration. If, (i) because of any change in law or in
applicable interpretations thereof by the staff of the Commission, the Company
is not permitted to effect a Registered Exchange Offer, as contemplated by
Section 1 hereof, (ii) the Registered Exchange Offer is not consummated by the
220th day after the Closing Date, (iii) any Initial Purchaser so requests with
respect to the Initial Securities (or the Private Exchange Securities) not
eligible to be exchanged for Exchange Securities in the Registered Exchange
Offer and held by it following consummation of the Registered Exchange Offer or
(iv) any Holder (other than an Exchanging Dealer) is not eligible to participate
in the Registered Exchange Offer or, in the case of any Holder (other than an
Exchanging Dealer) that participates in the Registered Exchange Offer, such
Holder does not receive freely tradeable Exchange Securities on the date of the
exchange and any such Holder so requests, the Company shall take the following
actions (the date on which any of the conditions described in the foregoing
clauses (i) through (iv) occur, including in the case of clauses (iii) or (iv)
the receipt of the required notice, being a "TRIGGER DATE"):

            (a) The Company shall promptly (but in no event more than 75 days
      after the Trigger Date (such 75th day being a "SHELF FILING DEADLINE"))
      file with the Commission and thereafter use its reasonable best efforts to
      cause to be declared effective (x) in the case of clause (i) above, no
      later than 180 days after the Closing Date and (y) otherwise no later than
      75 days after the Shelf Filing Deadline (such 180th day or 75th day being
      an "EFFECTIVENESS DEADLINE") a registration statement (the "SHELF
      REGISTRATION STATEMENT" and, together with the Exchange Offer Registration
      Statement, a "REGISTRATION STATEMENT") on an appropriate form under the
      Securities Act relating to the offer and sale of the Transfer Restricted
      Securities by the Holders thereof from time to time in accordance with the
      methods of distribution set forth in the Shelf Registration Statement and
      Rule 415 under the Securities Act (hereinafter, the "SHELF Registration");
      provided, however, that no Holder (other than an Initial Purchaser) shall
      be entitled to have the Securities held by it covered by such Shelf
      Registration Statement unless such Holder agrees in writing to be bound by
      all the provisions of this Agreement applicable to such Holder.

            (b) The Company shall use its reasonable best efforts to keep the
      Shelf Registration Statement continuously effective in order to permit the
      prospectus included therein to be lawfully delivered by the Holders of the
      relevant Securities, for a period of two years (or for such longer period
      if extended pursuant to Section 3(j) below) from the date of its
      effectiveness or such shorter period that will terminate when all the
      Securities covered by the Shelf Registration Statement (i) have been sold
      pursuant thereto or (ii) are no longer subject to restrictions on resale
      pursuant to Rule 144 under the Securities Act, or any successor rule
      thereof. The Company shall be deemed not to have used its reasonable best
      efforts to keep the Shelf Registration Statement effective during the
      requisite period if it voluntarily takes any action that would result in
      Holders of Securities covered thereby not being able to offer and sell
      such Securities during that period, unless such action is required by
      applicable law.

            (c) Notwithstanding any other provisions of this Agreement to the
      contrary, the Company shall cause the Shelf Registration Statement and the
      related prospectus and any amendment or supplement thereto, as of the
      effective date of the Shelf Registration Statement, amendment or
      supplement, (i) to comply in all material respects with the applicable
      requirements of the Securities Act and the rules and


                                       4


      regulations of the Commission and (ii) not to contain any untrue statement
      of a material fact or omit to state a material fact required to be stated
      therein or necessary in order to make the statements therein, in light of
      the circumstances under which they were made, not misleading.

      3. Registration Procedures. In connection with any Shelf Registration
contemplated by Section 2 hereof and, to the extent applicable, any Registered
Exchange Offer contemplated by Section 1 hereof, the following provisions shall
apply:

            (a) The Company shall (i) furnish to each Initial Purchaser, prior
      to the filing thereof with the Commission, a copy of the Registration
      Statement and each amendment thereof and each supplement, if any, to the
      prospectus included therein and, in the event that an Initial Purchaser
      (with respect to any portion of an unsold allotment from the original
      offering) is participating in the Registered Exchange Offer or the Shelf
      Registration Statement, the Company shall use its reasonable best efforts
      to reflect in each such document, when so filed with the Commission, such
      comments as such Initial Purchaser reasonably may propose; (ii) include
      the information set forth in Annex A hereto on the cover, in Annex B
      hereto in the "Exchange Offer Procedures" section and the "Purpose of the
      Exchange Offer" section and in Annex C hereto in the "Plan of
      Distribution" section of the prospectus forming a part of the Exchange
      Offer Registration Statement and include the information set forth in
      Annex D hereto in the Letter of Transmittal delivered pursuant to the
      Registered Exchange Offer; (iii) if requested by an Initial Purchaser,
      include the information required by Items 507 or 508 of Regulation S-K
      under the Securities Act, as applicable, in the prospectus forming a part
      of the Exchange Offer Registration Statement; (iv) include within the
      prospectus contained in the Exchange Offer Registration Statement a
      section entitled "Plan of Distribution," reasonably acceptable to the
      Initial Purchasers, which shall contain a summary statement of the
      positions taken or policies made by the staff of the Commission with
      respect to the potential "underwriter" status of any broker-dealer that is
      the beneficial owner (as defined in Rule 13d-3 under the Securities
      Exchange Act of 1934, as amended (the "EXCHANGE ACT")) of Exchange
      Securities received by such broker-dealer in the Registered Exchange Offer
      (a "PARTICIPATING BROKER-DEALER"), whether such positions or policies have
      been publicly disseminated by the staff of the Commission or such
      positions or policies, in the reasonable judgment of the Initial
      Purchasers based upon advice of counsel (which may be in-house counsel),
      represent the prevailing views of the staff of the Commission; and (v) in
      the case of a Shelf Registration Statement, include the names of the
      Holders who propose to sell Securities pursuant to the Shelf Registration
      Statement as selling securityholders.

            (b) The Company shall give written notice to the Initial Purchasers,
      the Holders of the Securities and any Participating Broker-Dealer from
      whom the Company has received prior written notice that it will be a
      Participating Broker-Dealer in the Registered Exchange Offer (which notice
      pursuant to clauses (ii)-(v) hereof shall be accompanied by an instruction
      to suspend the use of the prospectus until the requisite changes have been
      made):

                  (i) when the Registration Statement or any amendment thereto
            has been filed with the Commission and when the Registration
            Statement or any post-effective amendment thereto has become
            effective;

                  (ii) of any request by the Commission for amendments or
            supplements to the Registration Statement or the prospectus included
            therein or for additional information;

                  (iii) of the issuance by the Commission of any stop order
            suspending the effectiveness of the Registration Statement or the
            initiation of any proceedings for that purpose;

                  (iv) of the receipt by the Company or its legal counsel of any
            notification with respect to the suspension of the qualification of
            the Securities for sale in any jurisdiction or the initiation or
            threatening of any proceeding for such purpose; and

                  (v) of the happening of any event that requires the Company to
            make changes in the Registration Statement or the prospectus in
            order that the Registration Statement or the prospectus do not
            contain an untrue statement of a material fact nor omit to state a
            material fact required to be


                                       5


            stated therein or necessary to make the statements therein (in the
            case of the prospectus, in light of the circumstances under which
            they were made) not misleading.

            (c) The Company shall make every reasonable effort to obtain the
      withdrawal at the earliest possible time, of any order suspending the
      effectiveness of the Registration Statement.

            (d) The Company shall furnish to each Holder of Securities included
      within the coverage of the Shelf Registration, without charge, at least
      one copy of the Shelf Registration Statement and any post-effective
      amendment thereto, including financial statements and schedules, and, if
      the Holder so requests in writing, all exhibits thereto (including those,
      if any, incorporated by reference).

            (e) The Company shall deliver to each Exchanging Dealer and each
      Initial Purchaser, and to any other Holder who so requests, without
      charge, at least one copy of the Exchange Offer Registration Statement and
      any post-effective amendment thereto, including financial statements and
      schedules, and, if any Initial Purchaser or any such Holder requests, all
      exhibits thereto (including those incorporated by reference).

            (f) The Company shall, during the Shelf Registration Period, deliver
      to each Holder of Securities included within the coverage of the Shelf
      Registration, without charge, as many copies of the prospectus (including
      each preliminary prospectus) included in the Shelf Registration Statement
      and any amendment or supplement thereto as such person may reasonably
      request. The Company consents, subject to the provisions of this
      Agreement, to the use of the prospectus or any amendment or supplement
      thereto by each of the selling Holders of the Securities in connection
      with the offering and sale of the Securities covered by the prospectus, or
      any amendment or supplement thereto, included in the Shelf Registration
      Statement.

            (g) The Company shall deliver to each Initial Purchaser, any
      Exchanging Dealer, any Participating Broker-Dealer and such other persons
      required to deliver a prospectus following the Registered Exchange Offer,
      without charge, as many copies of the final prospectus included in the
      Exchange Offer Registration Statement and any amendment or supplement
      thereto as such persons may reasonably request. The Company consents,
      subject to the provisions of this Agreement, to the use of the prospectus
      or any amendment or supplement thereto by any Initial Purchaser, if
      necessary, any Participating Broker-Dealer and such other persons required
      to deliver a prospectus following the Registered Exchange Offer in
      connection with the offering and sale of the Exchange Securities covered
      by the prospectus, or any amendment or supplement thereto, included in
      such Exchange Offer Registration Statement.

            (h) Prior to any public offering of the Securities pursuant to any
      Registration Statement the Company shall register or qualify or cooperate
      with the Holders of the Securities included therein and their respective
      counsel in connection with the registration or qualification of the
      Securities for offer and sale under the securities or "blue sky" laws of
      such states of the United States as any Holder of the Securities
      reasonably requests in writing and do any and all other acts or things
      necessary or advisable to enable the offer and sale in such jurisdictions
      of the Securities covered by such Registration Statement; provided,
      however, that the Company shall not be required to (i) qualify generally
      to do business in any jurisdiction where it is not then so qualified or
      (ii) take any action which would subject it to general service of process
      or to taxation in any jurisdiction where it is not then so subject.

            (i) The Company shall cooperate with the Holders of the Securities
      to facilitate the timely preparation and delivery of certificates
      representing the Securities to be sold pursuant to any Registration
      Statement free of any restrictive legends and in such denominations and
      registered in such names as the Holders may request a reasonable period of
      time prior to sales of the Securities pursuant to such Registration
      Statement.

            (j) Upon the occurrence of any event contemplated by paragraphs (ii)
      through (v) of Section 3(b) above during the period for which the Company
      is required to maintain an effective Registration Statement, the Company
      shall promptly prepare and file a post-effective amendment to the
      Registration Statement or a supplement to the related prospectus and any
      other required document so that, as thereafter delivered to


                                       6


      Holders of the Securities or purchasers of Securities, the prospectus will
      not contain an untrue statement of a material fact or omit to state any
      material fact required to be stated therein or necessary to make the
      statements therein, in light of the circumstances under which they were
      made, not misleading. If the Company notifies the Initial Purchasers, the
      Holders of the Securities and any known Participating Broker-Dealer in
      accordance with paragraphs (ii) through (v) of Section 3(b) above to
      suspend the use of the prospectus until the requisite changes to the
      prospectus have been made, then the Initial Purchasers, the Holders of the
      Securities and any such Participating Broker-Dealers shall suspend use of
      such prospectus, and the period of effectiveness of the Shelf Registration
      Statement provided for in Section 2(b) above and the Exchange Offer
      Registration Statement provided for in Section 1 above shall each be
      extended by the number of days from and including the date of the giving
      of such notice to and including the date when the Initial Purchasers, the
      Holders of the Securities and any known Participating Broker-Dealer shall
      have received such amended or supplemented prospectus pursuant to this
      Section 3(j).

            (k) Not later than the effective date of the applicable Registration
      Statement, the Company will provide a CUSIP number for the Initial
      Securities, the Exchange Securities or the Private Exchange Securities, as
      the case may be, and provide the applicable trustee with printed
      certificates for the Initial Securities, the Exchange Securities or the
      Private Exchange Securities, as the case may be, in a form eligible for
      deposit with The Depository Trust Company.

            (l) The Company will comply with all rules and regulations of the
      Commission to the extent and so long as they are applicable to the
      Registered Exchange Offer or the Shelf Registration and will make
      generally available to its security holders (or otherwise provide in
      accordance with Section 11(a) of the Securities Act) an earnings statement
      satisfying the provisions of Section 11(a) of the Securities Act, no later
      than 45 days after the end of a 12-month period (or 90 days, if such
      period is a fiscal year) beginning with the first month of the Company's
      first fiscal quarter commencing after the effective date of the
      Registration Statement, which statement shall cover such 12-month period.

            (m) The Company shall cause the Indenture to be qualified under the
      Trust Indenture Act of 1939, as amended, in a timely manner and containing
      such changes, if any, as shall be necessary for such qualification. In the
      event that such qualification would require the appointment of a new
      trustee under the Indenture, the Company shall appoint a new trustee
      thereunder pursuant to the applicable provisions of the Indenture.

            (n) The Company may require each Holder of Securities to be sold
      pursuant to the Shelf Registration Statement to furnish to the Company
      such information regarding the Holder and the distribution of the
      Securities as the Company may from time to time reasonably require for
      inclusion in the Shelf Registration Statement, and the Company may exclude
      from such registration the Securities of any Holder that unreasonably
      fails to furnish such information within a reasonable time after receiving
      such request.

            (o) The Company shall enter into such customary agreements
      (including, if requested, an underwriting agreement in customary form) and
      take all such other action, if any, as any Holder of the Securities shall
      reasonably request in order to facilitate the disposition of the
      Securities pursuant to any Shelf Registration.

            (p) In the case of any Shelf Registration, the Company shall (i)
      make reasonably available for inspection by the Holders of the Securities,
      any underwriter participating in any disposition pursuant to the Shelf
      Registration Statement and any attorney, accountant or other agent
      retained by the Holders of the Securities or any such underwriter all
      relevant financial and other records, pertinent corporate documents and
      properties of the Company and (ii) cause the Company's officers,
      directors, employees, accountants and auditors to supply all relevant
      information reasonably requested by the Holders of the Securities or any
      such underwriter, attorney, accountant or agent in connection with the
      Shelf Registration Statement, in each case, as shall be reasonably
      necessary to enable such persons, to conduct a reasonable investigation
      within the meaning of Section 11 of the Securities Act; provided, however,
      that the foregoing inspection and information gathering shall be
      coordinated on behalf of the Initial Purchasers by you and on behalf of
      the


                                       7


      other parties, by one counsel designated by and on behalf of such other
      parties as described in Section 4 hereof.

            (q) In the case of any Shelf Registration, the Company, if requested
      by any Holder of Securities covered thereby, shall cause (i) its counsel
      to deliver an opinion and updates thereof relating to the Securities in
      customary form addressed to such Holders and the managing underwriters, if
      any, thereof and dated, in the case of the initial opinion, the effective
      date of such Shelf Registration Statement (it being agreed that the
      matters to be covered by such opinion shall include, without limitation,
      the incorporation or organization and good standing of the Company and its
      subsidiaries; the qualification of the Company and its subsidiaries to
      transact business as foreign corporations or limited partnerships; the due
      authorization, execution and delivery of the relevant agreement of the
      type referred to in Section 3(o) hereof; the due authorization, execution,
      authentication and issuance, and the validity and enforceability, of the
      applicable Securities; the absence of material legal or governmental
      proceedings involving the Company and its subsidiaries; the absence of
      governmental approvals required to be obtained in connection with the
      Shelf Registration Statement, the offering and sale of the applicable
      Securities, or any agreement of the type referred to in Section 3(o)
      hereof; the compliance as to form of such Shelf Registration Statement and
      any documents incorporated by reference therein and of the Indenture with
      the requirements of the Securities Act and the Trust Indenture Act,
      respectively; and, as of the date of the opinion and as of the effective
      date of the Shelf Registration Statement or most recent post-effective
      amendment thereto, as the case may be, the absence from such Shelf
      Registration Statement and the prospectus included therein, as then
      amended or supplemented, and from any documents incorporated by reference
      therein of an untrue statement of a material fact or the omission to state
      therein a material fact required to be stated therein or necessary to make
      the statements therein not misleading (in the case of any such documents,
      in the light of the circumstances existing at the time that such documents
      were filed with the Commission under the Exchange Act); (ii) its officers
      to execute and deliver all customary documents and certificates and
      updates thereof requested by any underwriters of the applicable Securities
      and (iii) its independent public accountants and the independent public
      accountants with respect to any other entity for which financial
      information is provided in the Shelf Registration Statement to provide to
      the selling Holders of the applicable Securities and any underwriter
      therefor a comfort letter in customary form and covering matters of the
      type customarily covered in comfort letters in connection with primary
      underwritten offerings, subject to receipt of appropriate documentation as
      contemplated, and only if permitted, by Statement of Auditing Standards
      No. 72.

            (r) In the case of the Registered Exchange Offer, if requested by
      any Initial Purchaser or any known Participating Broker-Dealer, the
      Company shall cause (i) its counsel to deliver to such Initial Purchaser
      or such Participating Broker-Dealer a signed opinion in the form set forth
      in Section 6(c) of the Purchase Agreement with such changes as are
      customary in connection with the preparation of a Registration Statement
      and (ii) its independent public accountants and the independent public
      accountants with respect to any other entity for which financial
      information is provided in the Registration Statement to deliver to such
      Initial Purchaser or such Participating Broker-Dealer a comfort letter, in
      customary form, meeting the requirements as to the substance thereof as
      set forth in Section 6(a) of the Purchase Agreement, with appropriate date
      changes.

            (s) If a Registered Exchange Offer or a Private Exchange is to be
      consummated, upon delivery of the Initial Securities by Holders to the
      Company (or to such other Person as directed by the Company) in exchange
      for the Exchange Securities or the Private Exchange Securities, as the
      case may be, the Company shall mark, or caused to be marked, on the
      Initial Securities so exchanged that such Initial Securities are being
      canceled in exchange for the Exchange Securities or the Private Exchange
      Securities, as the case may be; in no event shall the Initial Securities
      be marked as paid or otherwise satisfied.

            (t) The Company will use its reasonable best efforts to (a) if the
      Initial Securities have been rated prior to the initial sale of such
      Initial Securities, confirm such ratings will apply to the Securities
      covered by a Registration Statement, or (b) if the Initial Securities were
      not previously rated, cause the Securities covered by a Registration
      Statement to be rated with the appropriate rating agencies, if so
      requested by Holders of a majority in aggregate principal amount of
      Securities covered by such Registration Statement, or by the managing
      underwriters, if any.


                                       8


            (u) In the event that any broker-dealer registered under the
      Exchange Act shall underwrite any Securities or participate as a member of
      an underwriting syndicate or selling group or "assist in the distribution"
      (within the meaning of the Conduct Rules (the "RULES") of the National
      Association of Securities Dealers, Inc. ("NASD")) thereof, whether as a
      Holder of such Securities or as an underwriter, a placement or sales agent
      or a broker or dealer in respect thereof, or otherwise, the Company will
      assist such broker-dealer in complying with the requirements of such
      Rules, including, without limitation, by (i) if such Rules, including Rule
      2720, shall so require, engaging a "qualified independent underwriter" (as
      defined in Rule 2720) to participate in the preparation of the
      Registration Statement relating to such Securities, to exercise usual
      standards of due diligence in respect thereto and, if any portion of the
      offering contemplated by such Registration Statement is an underwritten
      offering or is made through a placement or sales agent, to recommend the
      yield of such Securities, (ii) indemnifying any such qualified independent
      underwriter to the extent of the indemnification of underwriters provided
      in Section 5 hereof and (iii) providing such information to such
      broker-dealer as may be required in order for such broker-dealer to comply
      with the requirements of the Rules.

            (v) The Company shall use its reasonable best efforts to take all
      other steps necessary to effect the registration of the Securities covered
      by a Registration Statement contemplated hereby.

      4. Registration Expenses.

            (a) All expenses incident to the Company's performance of and
      compliance with this Agreement will be borne by the Company, regardless of
      whether a Registration Statement is ever filed or becomes effective,
      including without limitation;

                  (i) all registration and filing fees and expenses;

                  (ii) all fees and expenses of compliance with federal
            securities and state "blue sky" or securities laws;

                  (iii) all expenses of printing (including printing
            certificates for the Securities to be issued in the Registered
            Exchange Offer and the Private Exchange and printing of
            Prospectuses), messenger and delivery services and telephone;

                  (iv) all fees and disbursements of counsel for the Company;
            and

                  (v) all fees and disbursements of independent certified public
            accountants of the Company (including the expenses of any special
            audit and comfort letters required by or incident to such
            performance).

The Company will bear its internal expenses (including, without limitation, all
salaries and expenses of its officers and employees performing legal or
accounting duties), the expenses of any annual audit and the fees and expenses
of any person, including special experts, retained by the Company.

            (b) In connection with any Registration Statement required by this
      Agreement, the Company will reimburse the Initial Purchasers and the
      Holders of Transfer Restricted Securities who are tendering Initial
      Securities in the Registered Exchange Offer and/or selling or reselling
      Securities pursuant to the "Plan of Distribution" contained in the
      Exchange Offer Registration Statement or the Shelf Registration Statement,
      as applicable, for the reasonable fees and disbursements of not more than
      one counsel, who shall be Cravath, Swaine & Moore unless another firm
      shall be chosen by the Holders of a majority in principal amount of the
      Transfer Restricted Securities for whose benefit such Registration
      Statement is being prepared.

      5. Indemnification.


                                       9


            (a) The Company agrees to indemnify and hold harmless each Holder of
      the Securities, any Participating Broker-Dealer and each person, if any,
      who controls such Holder or such Participating Broker-Dealer within the
      meaning of the Securities Act or the Exchange Act (each Holder, any
      Participating Broker-Dealer and such controlling persons are referred to
      collectively as the "INDEMNIFIED PARTIES") from and against any losses,
      claims, damages or liabilities, joint or several, or any actions in
      respect thereof (including, but not limited to, any losses, claims,
      damages, liabilities or actions relating to purchases and sales of the
      Securities) to which each Indemnified Party may become subject under the
      Securities Act, the Exchange Act or otherwise, insofar as such losses,
      claims, damages, liabilities or actions arise out of or are based upon any
      untrue statement or alleged untrue statement of a material fact contained
      in a Registration Statement or prospectus or in any amendment or
      supplement thereto or in any preliminary prospectus relating to a Shelf
      Registration, or arise out of, or are based upon, the omission or alleged
      omission to state therein a material fact required to be stated therein or
      necessary to make the statements therein not misleading, and shall
      reimburse, as incurred, the Indemnified Parties for any legal or other
      expenses reasonably incurred by them in connection with investigating or
      defending any such loss, claim, damage, liability or action in respect
      thereof; provided, however, that (i) the Company shall not be liable in
      any such case to the extent that such loss, claim, damage or liability
      arises out of or is based upon any untrue statement or alleged untrue
      statement or omission or alleged omission made in a Registration Statement
      or prospectus or in any amendment or supplement thereto or in any
      preliminary prospectus relating to a Shelf Registration in reliance upon
      and in conformity with written information pertaining to such Holder and
      furnished to the Company by or on behalf of such Holder specifically for
      inclusion therein and (ii) with respect to any untrue statement or
      omission or alleged untrue statement or omission made in any preliminary
      prospectus relating to a Shelf Registration Statement, the indemnity
      agreement contained in this subsection (a) shall not inure to the benefit
      of any Holder or Participating Broker-Dealer from whom the person
      asserting any such losses, claims, damages or liabilities purchased the
      Securities concerned, to the extent that a prospectus relating to such
      Securities was required to be delivered by such Holder or Participating
      Broker-Dealer under the Securities Act in connection with such purchase
      and any such loss, claim, damage or liability of such Holder or
      Participating Broker-Dealer results from the fact that there was not sent
      or given to such person, at or prior to the written confirmation of the
      sale of such Securities to such person, a copy of the final prospectus if
      the Company had previously furnished copies thereof to such Holder or
      Participating Broker-Dealer; provided further, however, that this
      indemnity agreement will be in addition to any liability which the Company
      may otherwise have to such Indemnified Party. The Company shall also
      indemnify underwriters, their officers and directors and each person who
      controls such underwriters within the meaning of the Securities Act or the
      Exchange Act to the same extent as provided above with respect to the
      indemnification of the Holders of the Securities if requested by such
      Holders.

            (b) Each Holder of the Securities, severally and not jointly, will
      indemnify and hold harmless the Company and each person, if any, who
      controls the Company within the meaning of the Securities Act or the
      Exchange Act from and against any losses, claims, damages or liabilities
      or any actions in respect thereof, to which the Company or any such
      controlling person may become subject under the Securities Act, the
      Exchange Act or otherwise, insofar as such losses, claims, damages,
      liabilities or actions arise out of or are based upon any untrue statement
      or alleged untrue statement of a material fact contained in a Registration
      Statement or prospectus or in any amendment or supplement thereto or in
      any preliminary prospectus relating to a Shelf Registration, or arise out
      of or are based upon the omission or alleged omission to state therein a
      material fact necessary to make the statements therein not misleading, but
      in each case only to the extent that the untrue statement or omission or
      alleged untrue statement or omission was made in reliance upon and in
      conformity with written information pertaining to such Holder and
      furnished to the Company by or on behalf of such Holder specifically for
      inclusion therein; and, subject to the limitation set forth immediately
      preceding this clause, shall reimburse, as incurred, the Company for any
      legal or other expenses reasonably incurred by the Company or any such
      controlling person in connection with investigating or defending any loss,
      claim, damage, liability or action in respect thereof. This indemnity
      agreement will be in addition to any liability which such Holder may
      otherwise have to the Company or any of its controlling persons.

            (c) Promptly after receipt by an indemnified party under this
      Section 5 of notice of the commencement of any action or proceeding
      (including a governmental investigation), such indemnified party will, if
      a claim in respect thereof is to be made against the indemnifying party
      under this Section 5,


                                       10


      notify the indemnifying party of the commencement thereof; but the
      omission so to notify the indemnifying party will not, in any event,
      relieve the indemnifying party from any obligations to any indemnified
      party other than the indemnification obligation provided in paragraph (a)
      or (b) above. In case any such action is brought against any indemnified
      party, and it notifies the indemnifying party of the commencement thereof,
      the indemnifying party will be entitled to participate therein and, to the
      extent that it may wish, jointly with any other indemnifying party
      similarly notified, to assume the defense thereof, with counsel reasonably
      satisfactory to such indemnified party (who shall not, except with the
      consent of the indemnified party, be counsel to the indemnifying party),
      and after notice from the indemnifying party to such indemnified party of
      its election so to assume the defense thereof the indemnifying party will
      not be liable to such indemnified party under this Section 5 for any legal
      or other expenses, other than reasonable costs of investigation,
      subsequently incurred by such indemnified party in connection with the
      defense thereof. No indemnifying party shall, without the prior written
      consent of the indemnified party, effect any settlement of any pending or
      threatened action in respect of which any indemnified party is or could
      have been a party and indemnity could have been sought hereunder by such
      indemnified party unless such settlement (i) includes an unconditional
      release of such indemnified party from all liability on any claims that
      are the subject matter of such action, and (ii) does not include a
      statement as to or an admission of fault, culpability or a failure to act
      by or on behalf of any indemnified party.

            (d) If the indemnification provided for in this Section 5 is
      unavailable or insufficient to hold harmless an indemnified party under
      subsections (a) or (b) above, then each indemnifying party shall
      contribute to the amount paid or payable by such indemnified party as a
      result of the losses, claims, damages or liabilities (or actions in
      respect thereof) referred to in subsection (a) or (b) above in such
      proportion as is appropriate to reflect the relative fault of the
      indemnifying party or parties on the one hand and the indemnified party on
      the other in connection with the statements or omissions that resulted in
      such losses, claims, damages or liabilities (or actions in respect
      thereof) as well as any other relevant equitable considerations. The
      relative fault of the parties shall be determined by reference to, among
      other things, whether the untrue or alleged untrue statement of a material
      fact or the omission or alleged omission to state a material fact relates
      to information supplied by the Company on the one hand or such Holder or
      such other indemnified party, as the case may be, on the other, and the
      parties' relative intent, knowledge, access to information and opportunity
      to correct or prevent such statement or omission. The amount paid by an
      indemnified party as a result of the losses, claims, damages or
      liabilities referred to in the first sentence of this subsection (d) shall
      be deemed to include any legal or other expenses reasonably incurred by
      such indemnified party in connection with investigating or defending any
      action or claim which is the subject of this subsection (d).
      Notwithstanding any other provision of this Section 5(d), the Holders of
      the Securities shall not be required to contribute any amount in excess of
      the amount by which the net proceeds received by such Holders from the
      sale of the Securities pursuant to a Registration Statement exceeds the
      amount of damages which such Holders have otherwise been required to pay
      by reason of such untrue or alleged untrue statement or omission or
      alleged omission. No person guilty of fraudulent misrepresentation (within
      the meaning of Section 11(f) of the Securities Act) shall be entitled to
      contribution from any person who was not guilty of such fraudulent
      misrepresentation. For purposes of this paragraph (d), each person, if
      any, who controls such indemnified party within the meaning of the
      Securities Act or the Exchange Act shall have the same rights to
      contribution as such indemnified party and each person, if any, who
      controls the Company within the meaning of the Securities Act or the
      Exchange Act shall have the same rights to contribution as the Company.

            (e) The agreements contained in this Section 5 shall survive the
      sale of the Securities pursuant to a Registration Statement and shall
      remain in full force and effect, regardless of any termination or
      cancellation of this Agreement or any investigation made by or on behalf
      of any indemnified party.


                                       11


      6. Additional Interest Under Certain Circumstances.

            (a) Additional interest (the "ADDITIONAL INTEREST") with respect to
      the Securities shall be assessed as follows if any of the following events
      occur (each such event in clauses (i) through (iv) below being herein
      called a "REGISTRATION DEFAULT"):

                  (i) any Registration Statement required by this Agreement is
            not filed with the Commission on or prior to the Filing Deadline or
            Shelf Filing Deadline, as applicable;

                  (ii) any Registration Statement required by this Agreement is
            not declared effective by the Commission on or prior to the
            applicable Effectiveness Deadline;

                  (iii) the Registered Exchange Offer has not been consummated
            on or prior to the Consummation Deadline; or

                  (iv) any Registration Statement required by this Agreement has
            been declared effective by the Commission but (A) such Registration
            Statement thereafter ceases to be effective or (B) such Registration
            Statement or the related prospectus ceases to be usable in
            connection with resales of Transfer Restricted Securities during the
            periods specified herein because either (1) any event occurs as a
            result of which the related prospectus forming part of such
            Registration Statement would include any untrue statement of a
            material fact or omit to state any material fact necessary to make
            the statements therein in the light of the circumstances under which
            they were made not misleading, or (2) it shall be necessary to amend
            such Registration Statement or supplement the related prospectus, to
            comply with the Securities Act or the Exchange Act or the respective
            rules thereunder.

Each of the foregoing will constitute a Registration Default whatever the reason
for any such event and whether it is voluntary or involuntary or is beyond the
control of the Company or pursuant to operation of law or as a result of any
action or inaction by the Commission .

Additional Interest shall accrue on the Securities over and above the interest
set forth in the title of the Securities from and including the date on which
any such Registration Default shall occur to but excluding the date on which all
such Registration Defaults have been cured, at a rate of 0.50% per annum (the
"ADDITIONAL INTEREST RATE") for the first 90-day period immediately following
the occurrence of such Registration Default. The Additional Interest Rate shall
increase by an additional 0.50% per annum with respect to each subsequent 90-day
period until all Registration Defaults have been cured, up to a maximum
Additional Interest Rate of 2.0% per annum.

      (b) A Registration Default referred to in Section 6(a)(iv) hereof shall be
deemed not to have occurred and be continuing in relation to a Shelf
Registration Statement or the related prospectus if (i) such Registration
Default has occurred solely as a result of (x) the filing of a post-effective
amendment to such Shelf Registration Statement to incorporate annual audited
financial information with respect to the Company where such post-effective
amendment is not yet effective and needs to be declared effective to permit
Holders to use the related prospectus or (y) other material events, with respect
to the Company that would need to be described in such Shelf Registration
Statement or the related prospectus and (ii) in the case of clause (y), the
Company is proceeding promptly and in good faith to amend or supplement such
Shelf Registration Statement and related prospectus to describe such events;
provided, however, that in any case if such Registration Default occurs for a
continuous period in excess of 30 days, Additional Interest shall be payable in
accordance with the above paragraph from the day such Registration Default
occurs until such Registration Default is cured.

      (c) Any amounts of Additional Interest due pursuant to Section 6(a) will
be payable in cash on the regular interest payment dates with respect to the
Securities. The amount of Additional Interest will be determined by multiplying
the applicable Additional Interest Rate by the principal amount of the
Securities and further multiplied by a fraction, the numerator of which is the
number of days such Additional Interest Rate was applicable during such period
(determined on the basis of a 360-day year comprised of twelve 30-day months),
and the denominator of which is 360.


                                       12


      (d) "TRANSFER RESTRICTED SECURITIES" means each Security until (i) the
date on which such Security has been exchanged by a person other than a
broker-dealer for a freely transferable Exchange Security in the Registered
Exchange Offer, (ii) following the exchange by a broker-dealer in the Registered
Exchange Offer of an Initial Security for an Exchange Security, the date on
which such Exchange Security is sold to a purchaser who receives from such
broker-dealer on or prior to the date of such sale a copy of the prospectus
contained in the Exchange Offer Registration Statement, (iii) the date on which
such Security has been effectively registered under the Securities Act and
disposed of in accordance with the Shelf Registration Statement or (iv) the date
on which such Security is distributed to the public pursuant to Rule 144 under
the Securities Act or is saleable pursuant to Rule 144(k) under the Securities
Act.

      7. Rules 144 and 144A. The Company shall use its best efforts to file the
reports required to be filed by it under the Securities Act and the Exchange Act
in a timely manner and, if at any time the Company is not required to file such
reports, it will, upon the request of any Holder of Securities, make publicly
available other information so long as necessary to permit sales of their
securities pursuant to Rules 144 and 144A. The Company covenants that it will
take such further action as any Holder of Securities may reasonably request, all
to the extent required from time to time to enable such Holder to sell
Securities without registration under the Securities Act within the limitation
of the exemptions provided by Rules 144 and 144A (including the requirements of
Rule 144A(d)(4)). The Company will provide a copy of this Agreement to
prospective purchasers of Initial Securities identified to the Company by the
Initial Purchasers upon request. Upon the request of any Holder of Initial
Securities, the Company shall deliver to such Holder a written statement as to
whether it has complied with such requirements. Notwithstanding the foregoing,
nothing in this Section 7 shall be deemed to require the Company to register any
of its securities pursuant to the Exchange Act.

      8. Underwritten Registrations. If any of the Transfer Restricted
Securities covered by any Shelf Registration are to be sold in an underwritten
offering, the investment banker or investment bankers and manager or managers
that will administer the offering ("MANAGING UNDERWRITERS") will be selected,
with the reasonable approval of the Company, by the Holders of a majority in
aggregate principal amount of such Transfer Restricted Securities to be included
in such offering.

      No person may participate in any underwritten registration hereunder
unless such person (i) agrees to sell such person's Transfer Restricted
Securities on the basis reasonably provided in any underwriting arrangements
approved by the persons entitled hereunder to approve such arrangements and (ii)
completes and executes all questionnaires, powers of attorney, indemnities,
underwriting agreements and other documents reasonably required under the terms
of such underwriting arrangements.

      9. Miscellaneous.

      (a) Remedies. The Company acknowledges and agrees that any failure by the
Company to comply with its obligations under Section 1 and 2 hereof may result
in material irreparable injury to the Initial Purchasers or the Holders for
which there is no adequate remedy at law, that it will not be possible to
measure damages for such injuries precisely and that, in the event of any such
failure, the Initial Purchasers or any Holder may obtain such relief as may be
required to specifically enforce the Company's obligations under Sections 1 and
2 hereof. The Company further agrees to waive the defense in any action for
specific performance that a remedy at law would be adequate.

      (b) No Inconsistent Agreements. The Company will not on or after the date
of this Agreement enter into any agreement with respect to its securities that
is inconsistent with the rights granted to the Holders in this Agreement or
otherwise conflicts with the provisions hereof. The rights granted to the
Holders hereunder do not in any way conflict with and are not inconsistent with
the rights granted to the holders of the Company's securities under any
agreement in effect on the date hereof.

      (c) Amendments and Waivers. The provisions of this Agreement may not be
amended, modified or supplemented, and waivers or consents to departures from
the provisions hereof may not be given, except by the Company and the written
consent of the Holders of a majority in principal amount of the Securities
affected by such amendment, modification, supplement, waiver or consent. Without
the consent of the Holder of each Security, however, no modification may change
the provisions relating to the payment of Additional Interest.


                                       13


      (d) Notices. All notices and other communications provided for or
permitted hereunder shall be made in writing by hand delivery, first-class mail,
facsimile transmission, or air courier which guarantees overnight delivery:

            (1) if to a Holder of the Securities, at the most current address
      given by such Holder to the Company.

            (2) if to the Initial Purchasers:

            Credit Suisse First Boston Corporation
            Eleven Madison Avenue
            New York, NY 10010-3629
            Fax No.: (212) 325-8278
            Attention: Transactions Advisory Group

      with a copy to:

            Cravath, Swaine & Moore
            Worldwide Plaza
            825 Eighth Avenue
            New York, New York 10019
            Fax No.: (212) 474-3700
            Attention: Stephen L. Burns

            (3) if to the Issuer or any Guarantor, at the Issuer's address as
      follows:

            Encore Acquisition Company
            777 Main Street
            Suite 1400
            Fort Worth, TX  76102
            Fax No.: (817) 877-0859
            Attention: John H. Karnes

      with a copy to:

            Kelly, Hart & Hallman, P.C.
            201 Main Street
            Suite 2500
            Fort Worth, TX  76102
            Fax No.: (817) 878-9280
            Attention: F. Richard Bernasek

      All such notices and communications shall be deemed to have been duly
given: at the time delivered by hand, if personally delivered; three business
days after being deposited in the mail, postage prepaid, if mailed; when receipt
is acknowledged by recipient's facsimile machine operator, if sent by facsimile
transmission; and on the day delivered, if sent by overnight air courier
guaranteeing next day delivery.

      (e) Third Party Beneficiaries. The Holders shall be third party
beneficiaries to the agreements made hereunder between the Company, on the one
hand, and the Initial Purchasers, on the other hand, and shall have the right to
enforce such agreements directly to the extent they may deem such enforcement
necessary or advisable to protect their rights or the rights of Holders
hereunder.

      (f) Successors and Assigns. This Agreement shall be binding upon the
Company and its successors and assigns.


                                       14


      (g) Counterparts. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

      (h) Headings. The headings in this Agreement are for convenience of
reference only and shall not limit or otherwise affect the meaning hereof.

      (i) Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO PRINCIPLES
OF CONFLICTS OF LAWS.

      (j) Severability. If any one or more of the provisions contained herein,
or the application thereof in any circumstance, is held invalid, illegal or
unenforceable, the validity, legality and enforceability of any such provision
in every other respect and of the remaining provisions contained herein shall
not be affected or impaired thereby.

      (k) Securities Held by the Company. Whenever the consent or approval of
Holders of a specified percentage of principal amount of Securities is required
hereunder, Securities held by the Company or its affiliates (other than
subsequent Holders of Securities if such subsequent Holders are deemed to be
affiliates solely by reason of their holdings of such Securities) shall not be
counted in determining whether such consent or approval was given by the Holders
of such required percentage.

      (l) Agent for Service; Submission to Jurisdiction; Waiver of Immunities.
By the execution and delivery of this Agreement, each of the Issuer and each
Guarantor submits to the nonexclusive jurisdiction of the Federal and state
courts in the Borough of Manhattan in the City of New York in any suit or
proceeding arising out of or relating to this Agreement or the transactions
contemplated hereby.

      If the foregoing is in accordance with your understanding of our
agreement, please sign and return to the Issuer a counterpart hereof, whereupon
this instrument, along with all counterparts, will become a binding agreement
among the several Initial Purchasers, the Issuer and the Guarantors in
accordance with its terms.

                                        Very truly yours,

                                        ENCORE ACQUISITION COMPANY

                                        by
                                            ____________________________________
                                            Name:  Morris B. Smith
                                            Title: Executive Vice President &
                                                     Chief Financial Officer


                                        EAP ENERGY, INC.

                                        by
                                            ____________________________________
                                            Name:  Morris B. Smith
                                            Title: Executive Vice President &
                                                     Chief Financial Officer


                                       15


                                        EAP ENERGY SERVICES, L.P.

                                             by EAP Energy, Inc.,
                                                its general partner

                                        by
                                            ____________________________________
                                            Name:  Morris B. Smith
                                            Title: Executive Vice President &
                                                     Chief Financial Officer


                                        EAP OPERATING, INC.

                                        by
                                            ____________________________________
                                            Name:  Morris B. Smith
                                            Title: Executive Vice President &
                                                     Chief Financial Officer


                                        EAP PROPERTIES, INC.

                                        by
                                            ____________________________________
                                            Name:  Morris B. Smith
                                            Title: Vice President


                                        ENCORE OPERATING, L.P.

                                             by EAP Operating, Inc.,
                                                its general partner

                                        by
                                            ____________________________________
                                            Name:  Morris B. Smith
                                            Title: Executive Vice President &
                                                     Chief Financial Officer


                                       16


The foregoing Registration Rights Agreement is hereby confirmed and accepted as
of the date first above written.

CREDIT SUISSE FIRST BOSTON CORPORATION

DEUTSCHE BANK SECURITIES INC.
FLEET SECURITIES, INC.
GOLDMAN, SACHS & CO.
WACHOVIA SECURITIES, INC.
BNP PARIBAS SECURITIES CORP.
FORTIS INVESTMENT SERVICES LLC
COMERICA SECURITIES, INC.
FROST SECURITIES, INC.

By: CREDIT SUISSE FIRST BOSTON CORPORATION


by
   ________________________________
   Name:
   Title:


                                       17