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                                 UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549



                                   FORM 11-K


      (Mark One)

                [X]  ANNUAL REPORT PURSUANT TO SECTION 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

FOR THE FISCAL YEAR ENDED DECEMBER 31, 2009

                                       OR

                [ ]  TRANSITION REPORT PURSUANT TO SECTION 15(d)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

FOR THE TRANSITION PERIOD FROM __________ TO __________


                         COMMISSION FILE NO. 001-06702


         A. Full title of the plan and address of the plan, if different from
that of the issuer named below:

                               NEXEN SAVINGS PLAN
                        5601 Granite Parkway Suite 1400
                            Plano, Texas 75024-6654

         B. Name of issuer of the securities held pursuant to the plan and the
address of its principal executive office:

                                   NEXEN INC.
                              801 - 7th Avenue SW
                        Calgary, Alberta, Canada T2P 3P7






NEXEN SAVINGS PLAN

FINANCIAL STATEMENTS AND SUPPLEMENTAL SCHEDULE

DECEMBER 31, 2009 AND 2008






                                C O N T E N T S

                                                                           Page


REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM......................1


FINANCIAL STATEMENTS

     Statements of Net Assets Available for Benefits.........................2

     Statements of Changes in Net Assets Available for Benefits..............3

     Notes to Financial Statements...........................................4


SUPPLEMENTAL SCHEDULE *

     Schedule H, line 4i - Schedule of Assets (Held at End of Year).........19



     * Other  schedules  required by 29 CFR  2520.103-10  of the  Department of
     Labor's Rules and Regulations for Reporting and Disclosure  under Employee
     Retirement  Income Security Act of 1974 have been omitted because they are
     not applicable.





                  [LETTERHEAD OF WEAVER AND TIDWELL, L.L.P.]



                        REPORT OF INDEPENDENT REGISTERED
                             PUBLIC ACCOUNTING FIRM


To the Administrative Committee
NEXEN SAVINGS PLAN
Plano, Texas

We have  audited  the  accompanying  statements  of net  assets  available  for
benefits  of the (the Plan) as of December  31, 2009 and 2008,  and the related
statements  of changes in net assets  available for benefits for the years then
ended.  These financial  statements and the supplemental  schedule  referred to
below  are the  responsibility  of the  Plan's  Administrative  Committee.  Our
responsibility  is to  express an opinion  on these  financial  statements  and
schedule based on our audits.

We conducted our audits in accordance  with the standards of the Public Company
Accounting  Oversight Board (United  States).  Those standards  require that we
plan and perform the audits to obtain  reasonable  assurance  about whether the
financial  statements  are free of  material  misstatement.  An audit  includes
examining,  on a test basis, evidence supporting the amounts and disclosures in
the  financial  statements.  An audit also includes  assessing  the  accounting
principles  used  and  significant  estimates  made by  management,  as well as
evaluating the overall financial  statement  presentation.  We believe that our
audits provide a reasonable basis for our opinion.

In our opinion,  the financial  statements referred to above present fairly, in
all  material  respects,  the net assets  available  for  benefits of the Nexen
Savings  Plan as of  December  31,  2009 and 2008,  and the  changes in its net
assets  available  for benefits for the years then ended,  in  conformity  with
accounting principles generally accepted in the United States of America.

Our audits  were  performed  for the purpose of forming an opinion on the basic
financial  statements  taken as a whole.  The  supplemental  schedule of assets
(held at end of year) is presented for purposes of  additional  analysis and is
not a required  part of the basic  financial  statements  but is  supplementary
information  required by the  Department of Labor's Rules and  Regulations  for
Reporting and Disclosure under the Employee  Retirement  Income Security Act of
1974. The supplemental  schedule has been subjected to the auditing  procedures
applied in the audit of the basic financial  statements and, in our opinion, is
fairly  stated in all  material  respects in  relation  to the basic  financial
statements taken as a whole.


/s/ Weaver and Tidwell, L.L.P.

WEAVER AND TIDWELL, L.L.P.

Dallas, Texas
June 23, 2010






                               NEXEN SAVINGS PLAN
                STATEMENTS OF NET ASSETS AVAILABLE FOR BENEFITS
                           DECEMBER 31, 2009 AND 2008


                                                                      2009            2008
                                                               --------------  --------------
                                                                         
                                     ASSETS
     Cash                                                       $    183,602    $    197,139
     Investments, at fair value                                   74,560,448      37,692,731
     Investment trades receivable                                    124,819            -
     Accrued dividends receivable                                       -             26,221
     Participant loans                                               804,239         808,274
                                                               --------------  --------------

TOTAL ASSETS                                                      75,673,108      38,724,365
                                                               --------------  --------------

                                   LIABILITIES
     Due to broker                                                   183,942         172,448
     Other payables                                                     -                  5
                                                               --------------  --------------

TOTAL LIABILITIES                                                    183,942         172,453
                                                               --------------  --------------

NET ASSETS AVAILABLE FOR BENEFITS AT FAIR VALUE                   75,489,166      38,551,912

     Adjustment from fair value to contract value for
         fully benefit-responsive investment contracts               (68,943)        219,680
                                                               --------------  --------------

NET ASSETS AVAILABLE FOR BENEFITS                               $ 75,420,223    $ 38,771,592
                                                               ==============  ==============




The Notes to Financial Statements are
an integral part of these statements.

                                       2





                               NEXEN SAVINGS PLAN
           STATEMENTS OF CHANGES IN NET ASSETS AVAILABLE FOR BENEFITS
                 FOR THE YEARS ENDED DECEMBER 31, 2009 AND 2008


                                                                  2009              2008
                                                           ----------------------------------
                                                                         
ADDITIONS
     Investment income:
         Net appreciation (depreciation)
            in fair value of investments                     $  11,012,611     $ (20,741,133)
         Interest                                                   54,760            75,112
         Dividends                                                 616,717         1,454,258
                                                           ----------------   ---------------

                                                                11,684,088       (19,211,763)
                                                           ----------------   ---------------

     Contributions:
         Participants                                            3,280,741         2,883,061
         Employer                                                2,196,049         1,862,516
         Rollover                                                      315           109,074
                                                           ----------------   ---------------

                                                                 5,477,105         4,854,651
                                                           ----------------   ---------------

     Other income                                                    7,747              -
     Transfer into plan                                         22,313,374            64,116
                                                           ----------------   ---------------


NET ADDITIONS                                                   39,482,314       (14,292,996)
                                                           ----------------   ---------------

DEDUCTIONS

     Benefits paid to participants                               2,828,467         5,724,076
     Administrative expenses                                         5,216             4,656
                                                           ----------------   ---------------

TOTAL DEDUCTIONS                                                 2,833,683         5,728,732
                                                           ----------------   ---------------

NET INCREASE (DECREASE) IN NET
     ASSETS AVAILABLE                                           36,648,631       (20,021,728)

NET ASSETS AVAILABLE FOR BENEFITS,
     BEGINNING OF YEAR                                          38,771,592        58,793,320
                                                           ----------------   ---------------

NET ASSETS AVAILABLE FOR BENEFITS,
      END OF YEAR                                            $  75,420,223      $ 38,771,592
                                                           ================   ===============




The Notes to Financial Statements are
an integral part of these statements.

                                       3



                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 1.   DESCRIPTION OF THE PLAN

     The  following  description  of the (the  Plan) is  provided  for  general
     information purposes only. More complete information  regarding the Plan's
     provisions may be found in the Plan Document.

     GENERAL

         The Plan is a defined  contribution plan that was adopted September 1,
         1988, and amended and restated  effective  January 1, 2002, to provide
         eligible  employees of Nexen Petroleum  U.S.A.  Inc. (the Company) and
         Nexen Marketing  U.S.A.  Inc. (the  Participating  Employers),  wholly
         owned  subsidiaries  of Nexen Inc., a method to meet their  long-range
         financial  objectives  under the requirements of Section 401(k) of the
         Internal Revenue Code.

         Charles  Schwab Trust Company (the  Trustee) is the Plan trustee,  and
         the recordkeeping  function is performed by Schwab Retirement Services
         Company, formerly known as "The 401(k) Company" (the Recordkeeper).

         On December 31, 2009,  the Company  merged the Nexen Pension Plan into
         the Nexen Savings Plan. All investments were reregistered to the Nexen
         Savings  Plan from the Nexen  Pension  Plan,  and a transfer  into the
         Nexen Savings Plan in the amount of  $22,313,374  was  recognized  and
         reflected  on the  statement  of changes in net assets  available  for
         benefits.  Effective  January  1,  2010,  the Nexen  Savings  Plan was
         renamed as the Nexen 401(k) Savings and Pension Plan.

     ELIGIBILITY

         All regular employees of the Company and  Participating  Employers who
         are 18 years of age and over are eligible to  participate  in the Plan
         on the entry date  coinciding  with or following the date the employee
         attains age 18.

     CONTRIBUTIONS

         Participant  contributions  are made on a voluntary basis and directly
         withheld from the participant's eligible  compensation,  as defined in
         the Plan Document.  The Plan offers  participants the option of making
         Salary  Deferral   Contributions  and/or  Roth  401(k)  Contributions.
         Contributions may be made with: pretax dollars;  after-tax dollars; or
         a combination of pretax and after-tax dollars.  Eligible  compensation
         excludes overtime and bonuses.  Participants are immediately vested in
         their employee contribution account and actual earnings thereon.


                                       4


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 1.   DESCRIPTION OF THE PLAN - CONTINUED

     CONTRIBUTIONS - CONTIUED

         The Company and Participating Employers will match 100% of Participant
         contributions  up to 6% of the  Participant's  eligible  compensation.
         Participants  are immediately  100% vested in their employer  matching
         account.

         The Company and  Participating  Employers  will begin making a pension
         contribution to the Plan effective  January 1, 2010. The  contribution
         is equivalent  to the former  pension plan  contribution  in the Nexen
         Pension Plan which is 6% of an eligible participant's  compensation up
         to the  social  security  wage  base and  11.5%  thereafter  until the
         compensation limit is reached.

     VESTING

         Vesting in the Plan is based on the following schedule:

                                             Vested Percentage
                                  --------------------------------------------

           Years of Credited        401(k) Matching          Employer Pension
               Service                 Account                  Account
         --------------------     --------------------------------------------
         Less than 2                      100%                       0%
         2 or more                        100%                      100%


     FORFEITURES

         At December 31, 2009,  forfeited  amounts  totaling $69,457 related to
         the Nexen Pension Plan were  transferred  into the Nexen Savings Plan.
         Forfeitures  from the Nexen Pension Plan which were  transferred  into
         the Nexen  Savings Plan related to  non-vested  interest in terminated
         employees  pension  accounts  which are to be used to: (a) restore any
         prior forfeited  amounts in an employee's  account whom was previously
         terminated,  rehired,  and meets the  requirements  to  receive  their
         original  nonvested portion which had been forfeited,  (b) used to pay
         any reasonable and necessary  expenses incurred in connection with the
         administration  of the  Plan as the  Plan's  Administrative  Committee
         directs, or (c) applied to reduce the amount of matching contributions
         and employee pension  contributions  the employer would otherwise make
         under  the  terms  of the  Plan.  As of  December  31,  2009  and 2008
         unallocated forfeitures totaled $69,457 and $72,264, respectively.


                                       5


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 1.   DESCRIPTION OF THE PLAN - CONTINUED

     INVESTMENTS

         The Plan's  investment  options are: (1) Charles  Schwab  Stable Value
         Fund,  Select Unit Class (2) Vanguard  Total Bond Market Index Signal,
         (3) American  Century  Real Estate  Investment  Fund,  (4) Royce Value
         Service  Fund,  (5) DWS Equity 500 Index S Fund,  (6)  American  Funds
         Growth  Fund of  America  A,  (7)  First  Eagle  Overseas  Fund A, (8)
         American Funds  EuroPacific Gr A, (9) American Funds Washington Mutual
         A, (10) Oppenheimer Developing Markets Fund A, (11) Third Avenue Value
         Insti  Cl,  (12)  American  Beacon  Small Cp Val Inv,  (13)  Federated
         Capital  Reserves,  and (14) Nexen Inc.  Stock  Fund.  All Company and
         Participating Employers' contributions are invested in accordance with
         the investment choices selected by each respective Participant.

     PAYMENTS OF BENEFITS

         Distribution  of a  Participant's  entire account becomes due in three
         ways:  (1)  upon   termination  of  employment,   (2)  death,  or  (3)
         disability,  as  defined  in the Plan  Document.  At the option of the
         Participant or beneficiary,  such account  balances may be distributed
         in  a  lump-sum  payment  or  via  periodic  installment  payments  as
         described in the Plan Document.

         Withdrawals  from the Plan by active  Participants  are  permitted for
         specific  instances of financial  hardship and age 59 1/2 withdrawals,
         which  can be made  once  every  six  months.  Once per Plan  year,  a
         Participant  may withdraw a portion or all of his or her after-tax and
         rollover account, subject to a $250 minimum.

     BASIS OF ACCOUNTING

         The  financial  statements  of the Plan are  presented  on the accrual
         basis of accounting in accordance with accounting principles generally
         accepted in the United States of America.  Current year contributions,
         expenses,   and  investment   income,   including  both  interest  and
         dividends,  which are not received or paid until the subsequent  year,
         are accrued in the current year. Benefits are recorded when paid.

     USE OF ESTIMATES

         The preparation of financial  statements in conformity with accounting
         principles generally accepted in the United States of America requires
         management to make estimates and assumptions  that affect the reported
         amounts  of net  assets  available  for  benefits  and  disclosure  of
         contingent  assets  and  liabilities  at the  date  of  the  financial
         statements  and the reported  amounts of  additions to and  deductions
         from net assets  available for benefits  during the reporting  period.
         Actual results could differ from those estimates.


                                       6


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 2.   SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

     INVESTMENTS

         Investments  are stated at fair value based on quoted market prices at
         the Plan's year end.  Purchases and sales of investments  are recorded
         on a trade date basis. Participants may direct their contributions and
         any related earnings into many distinct investment options,  including
         the Nexen Inc.  Stock  Fund.  Interest  is  allocated  to  Participant
         accounts on a pro-rata basis  depending on the  Participants'  account
         balance.  Dividends are  allocated  based on the number of shares in a
         Participant's account.

     NATURE OF INVESTMENT CONTRACTS

         The Plan's Charles Schwab Stable Value Class S Fund (the Fund) invests
         primarily in wrap contracts (also known as synthetic  GICs). In a wrap
         contract, the underlying investments are owned by the Fund and held in
         trust for plan  participants.  The Fund  purchases wrap contracts from
         high-quality  insurance companies or banks that serve to substantially
         offset the price fluctuations in the underlying  investments caused by
         movements  in  interest  rates.  Each  wrap  contract   obligates  the
         principal  amounts  invested  in  the  underlying  investments,   plus
         interest accrued at a crediting rate  established  under the contract,
         less  any  adjustments  for  withdrawals  (as  specified  in the  wrap
         agreement).  Under the terms of the wrap  contract,  the  realized and
         unrealized  gains and losses on the  underlying  investments  are,  in
         effect,  amortized  over the duration of the  underlying  investments,
         through  adjustments to the future  contract  interest  crediting rate
         (which  is the  rate  earned  by  participants  in the  Fund  for  the
         underlying   investments).   The  wrap  contract   provides  that  the
         adjustments  to the  interest  crediting  will not  result in a future
         interest  crediting  rate that is less than zero.  This  ensures  that
         participants' principal and accrued interest will be protected.

         In general,  if the contract value of the wrap  agreement  exceeds the
         market  value  of  the  underlying   investments   (including  accrued
         interest), the wrap issuer becomes obligated to pay that difference to
         the Fund in the event that shareholder  redemptions  result in a total
         liquidation.   In  the  event  that  there  are  partial   shareholder
         redemptions  that would otherwise cause the contract's  crediting rate
         to fall below zero percent, the wrap issuer is obligated to contribute
         to the Fund an amount  necessary to maintain the contract's  crediting
         rate at least zero percent.  The circumstance under which payments are
         made and the timing of  payments  between the Fund and the wrap issuer
         may vary based on the terms of the wrap contract.


                                       7


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 2.   SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - CONTINUED

     NATURE OF INVESTMENT CONTRACTS - CONTINUED

         In certain circumstances,  the amount withdrawn from the wrap contract
         would be payable at fair value  rather than at contract  value.  These
         events include  termination of the Plan, a material  adverse change to
         the  provisions  of the Plan,  the employer  elects to withdraw from a
         wrap contract in order to switch to a different  investment  provider,
         or if the terms of a successor  plan (in the event of the  spin-off or
         sale  of  a  division)  do  not  meet  the  wrap   contract   issuer's
         underwriting criteria for issuance of a clone wrap contract.

         While it is possible that some of the plans  participating in the Fund
         may experience  plan  terminations  or other events that would trigger
         fair value  payouts under the Fund's wrap  agreements,  based on prior
         experience,  management  of the Fund  believes it is not probable that
         such events would be of  sufficient  magnitude to limit the ability of
         the Fund to transact at contract  value with the  participants  in the
         Fund.  Given that such  events  are  beyond  the  control of the Plan,
         however, there can be no guarantee that this will be the case.

         Average yields for Charles Schwab Stable Value Fund

                                                                  Year ended
                                                                 December 31,
                                                               ---------------
                                                                2009     2008
                                                               ------   ------
           Based on actual earnings (at fair value)             2.65%    5.25%
           Based on interest rate credited to
                participants (at fair value)                    3.06%    3.72%

         The Plan follows  current  guidance on investment  contracts held by a
         defined-contribution plan which requires these types of investments to
         be reported at fair value.  However,  contract  value is the  relevant
         measurement attribute for that portion of the net assets available for
         benefits  of  a  defined   contribution  plan  attributable  to  fully
         benefit-responsive  investment contracts because contract value is the
         amount  participants  would receive if they were to initiate permitted
         transactions under the terms of the plan. As required,  the Statements
         of Net Assets  Available  for  Benefits  present the fair value of the
         investment   contracts  as  well  as  the   adjustment  of  the  fully
         benefit-responsive  investment  contracts  from fair value to contract
         value.  The Statements of Changes in Net Assets Available for Benefits
         are prepared on a contract value basis.


                                       8


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 2.   SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - CONTINUED

     MARKET AND CREDIT RISKS

         The Plan invests in a variety of investments.  Investments are exposed
         to various risks,  such as interest rate, market and credit risks. Due
         to the level of risk  associated  with certain  investments,  it is at
         least  reasonably  possible  that the  changes  in the  values  of the
         investments  will occur in the near term and that such  changes  could
         materially  affect the amount reported in the Plan's  statement of net
         assets available for benefits.

     ADMINISTRATION

         The Plan is administered  by the  Administrative  Committee,  which is
         composed  of  members  who are either  officers  or  employees  of the
         Company.  Investment  options for the Plan are selected by the Benefit
         Plan Design Committee from funds available  through the  Recordkeeper.
         Some of the fund providers  charge 12b-1 fees at the fund level before
         earnings are paid to investors.

         The  Recordkeeper  receives fees from these fund  providers from 12b-1
         fees charged to the funds. 12b-1 fees received by the Recordkeeper are
         based on Plan  assets  invested in each fund.  Similarly,  all Trustee
         fees for the Plan are  received  from 12b-1 fees charged to the funds.
         12b-1 fees  received  by the  Trustee  are also  based on Plan  assets
         invested in each fund.

     LOANS TO PARTICIPANTS

         Participant  loans receivable are stated at cost,  which  approximates
         fair value. A Participant may borrow up to the lesser of 50% of his or
         her vested  account  balance or $50,000  with a minimum loan amount of
         $1,000.  The vested account balance for loans does not include pension
         sources.  Loans are repayable through payroll  deductions over periods
         ranging up to 60 months.  Participants  are  charged a $50 loan set-up
         fee with a $2 monthly  maintenance fee per loan. The loans are secured
         by a lien on the  borrower's  vested  account  balance in the Plan and
         bear interest at rates based on prevailing market conditions. Interest
         rates on outstanding  loans ranged from 4.43% to 9.13% at December 31,
         2009.


                                       9


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 2.   SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - CONTINUED

     PLAN TERMINATION

         Although it has not  expressed any intention to do so, the Company has
         the right to terminate the Plan  pursuant to  provisions  set forth by
         the Plan Document and subject to the provisions of ERISA. In the event
         of Plan  termination,  each  Participant's  account shall become fully
         vested and  Participants  will be entitled to  distributions  of their
         entire accounts.

     NEW ACCOUNTING PRONOUNCEMENTS

         In April 2009, the FASB issued  guidance under ASC 820 for determining
         fair  value when the  volume  and level of  activity  for the asset or
         liability have  significantly  decreased and identifying  transactions
         that are not orderly. This standard incorporates a two-step process to
         determine  whether a market is not  active  and a  transaction  is not
         distressed. The Plan adopted guidance under this standard for the Plan
         year ended  December 31, 2009.  The effects of adopting  this standard
         did not have a material impact on the Plan's financial statements.

         In June 2009, the FASB issued  guidance  which  requires  companies to
         recognize in the financial statements the effects of subsequent events
         that provide additional  evidence about conditions that existed at the
         date of the Statement of Net Assets Available for Benefits,  including
         the  estimates   inherent  in  the  process  of  preparing   financial
         statements. Companies are not permitted to recognize subsequent events
         that provide  evidence about conditions that did not exist at the date
         of the Statement of Net Assets  Available for Benefits but arose after
         the  Statement of Net Assets  Available  for Benefits  date and before
         financial statements are issued. Some non-recognized subsequent events
         must  be  disclosed  to  keep  the  financial  statements  from  being
         misleading.  For such events a company must disclose the nature of the
         event, an estimate of its financial  effect,  or a statement that such
         an estimate cannot be made. This guidance  applies  prospectively  for
         interim or annual  financial  periods  ending after June 15, 2009. The
         adoption of this  guidance did not affect the  financial  condition or
         income and  changes in Plan net  assets.  The Plan has  evaluated  its
         subsequent  events  through  June 23,  2010,  the  date the  financial
         statements are available to be issued.


                                      10


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 2.   SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - CONTINUED

     NEW ACCOUNTING PRONOUNCEMENTS - CONTINUED

         In June 2009,  the FASB issued  guidance which  established  the "FASB
         Accounting Standards Codification" (Codification) as the single source
         of authoritative  nongovernmental U.S. GAAP which was launched on July
         1, 2009.  The  Codification  does not change current U.S. GAAP, but is
         intended to simplify  user access to all  authoritative  U.S.  GAAP by
         providing  all the  authoritative  literature  related to a particular
         topic in one place. All existing accounting standard documents will be
         superseded  and all other  accounting  literature  not included in the
         Codification   will  be   considered   non-authoritative.   Rules  and
         interpretive  releases of the Securities and Exchange Commission (SEC)
         under  authority  of  federal  securities  laws  are also  sources  of
         authoritative GAAP for SEC registrants.  The Codification is effective
         for interim and annual periods ending after September 15, 2009 and did
         not have an impact on the Plan's financial statements.


NOTE 3.   INVESTMENT PROGRAMS

     As  of  December  31,  2009,  the  investment   alternatives  include  the
     following:

         NEXEN  INC.  STOCK FUND - provides  ownership  interest  in Nexen Inc.
         common stock. Quarterly blackout periods apply to this fund and during
         such  blackout  periods,  participants  are unable to purchase or sell
         shares of Nexen Inc. common stock.

         CHARLES  SCHWAB  STABLE  VALUE  FUND,  SELECT UNIT CLASS - The Charles
         Schwab  Stable Value Fund is a collective  investment  trust fund that
         allows  participants to invest in stable value assets.  The fund seeks
         to provide  investors  with a stable rate of return  while  preserving
         principal and maintaining liquidity.

         AMERICAN  BEACON  SMALL CP VAL INV - is a small  value fund that seeks
         long-term  capital  appreciation  and current income by investing over
         80% of its assets in equity  securities of companies within the United
         States.

         VANGUARD  TOTAL  BOND  MARKET  INDEX  SIGNAL - is a fund that seeks to
         track the performance of a broad, market-weighted bond index.

         AMERICAN CENTURY REAL ESTATE INVESTMENT FUND - seeks long-term capital
         appreciation;  current income is a secondary  consideration.  The fund
         invests at least 80% of assets in equities  issued by companies in the
         real estate industry.

         ROYCE VALUE SERVICE FUND - is a small growth fund that seeks long-term
         capital  appreciation  by  investing  at least 80% of assets in equity
         securities.


                                      11


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 3.   INVESTMENT PROGRAMS - CONTINUED

         DWS  EQUITY  500 INDEX S FUND - is a large  company  growth and income
         fund that invests primarily in equity securities of companies included
         in the S&P 500.

         AMERICAN  FUNDS GROWTH FUND OF AMERICA A - is a large growth fund that
         seeks capital growth by investing primarily in common stocks. The fund
         may  invest up to 15% of assets in  securities  of  issuers  domiciled
         outside of the United States and Canada.

         FIRST  EAGLE  OVERSEAS  FUND A - is a foreign  stock  fund that  seeks
         long-term  capital growth by investing  primarily in equities of small
         and mid-sized foreign companies in developed and emerging markets.

         AMERICAN  FUNDS  EUROPACIFIC  GR A - is a large company  foreign stock
         fund  that  seeks  long-term  capital  appreciation  by  investing  in
         companies domiciled in developed countries outside the United States.

         AMERICAN FUNDS WASHINGTON MUTUAL A - is a large company value-oriented
         growth and income fund.

         OPPENHEIMER  DEVELOPING  MARKETS FUND A - is an emerging markets stock
         fund that seeks  long-term  growth by  investing in stock of issues in
         countries with developing markets.

         THIRD  AVENUE  VALUE  INSTI  CL - is a small  value  fund  that  seeks
         long-term  capital  appreciation  by  investing  in equity  securities
         issued by companies  that are believed to be  undervalued  and to have
         strong financial positions and responsible management.

         FEDERATED  CAPITAL RESERVES - Seeks to provide  investors with current
         income consistent with stability of principle and liquidity.  The fund
         pursues  its  objective  by  investing  primarily  in a  portfolio  of
         short-term,  high-quality,  fixed-income  securities  issued by banks,
         corporations, and the U.S. government.


                                      12


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 4.   TAX STATUS

     The Plan  received a  favorable  determination  letter  from the  Internal
     Revenue  Service  dated  April  5,  2002,  stating  that  the Plan and its
     amendments are qualified under Section 401(a) of the Internal Revenue Code
     of 1986,  as amended  (the Code),  and the trust is exempt  from  taxation
     under Section 501(a) of the Code. The trust  established under the Plan to
     hold the Plan's assets is intended to qualify  pursuant to the appropriate
     section of the Internal  Revenue Code as a  tax-exempt  organization.  The
     Plan has been amended since receiving the determination  letter.  However,
     the Company and the Plan's tax counsel believe that the trust continues to
     qualify and operate as designed.


NOTE 5.   INVESTMENTS

     Investments that represent 5% or more of the net assets available for Plan
     benefits at December 31, 2009 and 2008 are as follows:



                                                                   December 31,    December 31,
                                                                       2009            2008
                                                                    Fair Value      Fair Value
                                                                 --------------  --------------
                                                                           
         Bond Fund of America A                                   $                $ 2,886,524
         EuroPacific Growth Fund A                                   6,476,852       2,633,576
         Nexen Inc. Stock Fund                                      16,405,315      11,126,459
         Schwab Stable Value Class S                                 9,995,303       4,528,717
         Vanguard Total Bond Market                                  5,669,546
         Washington Mutual Investors Fund A                          7,297,581       3,598,463
         Oppenheimer Developing Markets Fund A                       4,843,033
         Growth Fund of America A                                    5,857,423       2,410,347
         DWS Equity 500 Index S                                      4,831,307       2,012,263


     During 2009 and 2008, the Plan's  investments  (including gains and losses
     on investments bought and sold, as well as held during the year) increased
     (decreased) in value by $11,684,088 and  $(19,211,763),  respectively,  as
     follows:



                                             2009                                     2008
                                -------------------------------   -------------------------------
                                                  Realized and                      Realized and
                                 Interest and      Unrealized      Interest and      Unrealized
                                   Dividends     Gains (losses)      Dividends     Gains (losses)
                                --------------  ---------------   --------------  ---------------
                                                                      
         Mutual funds               $ 534,367      $ 6,583,643       $1,390,669     $(13,024,048)
         Stock funds                   82,350        4,428,968           76,163       (7,717,085)
         Loans to Participants         54,760                            62,538



                                      13


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 6.   PLAN AMENDMENTS

     On November 19, 2008, the Twelfth  Amendment to the Nexen Savings Plan was
     executed and  adopted.  The purpose of the  amendment  was to exclude from
     participation  in the Plan  employees  whose  base  salary  is paid on the
     payroll  of a foreign  Affiliate,  regardless  of whether a portion of the
     Employee's compensation or wages is also paid or provided by an Employer.

     On December 18, 2008, the  Thirteenth  Amendment to the Nexen Savings Plan
     was executed and adopted.  The purpose of the  amendment  was to 1) update
     the  employer's  address to the  location at 5601 Granite  Parkway,  Suite
     1400, in Plano, Texas 75024, and 2) to bring the Plan into compliance with
     the gap period income provisions of the Pension Protection Act of 2006 and
     Code section 415 final regulations adopted by the Internal Revenue Service
     on April 5, 2007.

     On November 30, 2009, the  Fourteenth  Amendment to the Nexen Savings Plan
     was executed and adopted. The purpose of this amendment was to restate the
     Income  Allocable to Excess  Deferrals  section of the Plan Document.  For
     plan years beginning on or after January 1, 2008, the income  allocable to
     excess deferrals is equal to the sum of the allocable gain or loss for the
     taxable year of the individual and does not include gap period income.

NOTE 7.   FAIR VALUE MEASUREMENT

     In  accordance  with  current  guidance  on fair  value  measurements  and
     disclosures,  the Plan  defines  fair  value as the  price  that  would be
     received  from  selling  an asset or paid to  transfer a  liability  in an
     orderly  transaction  between market participants at the measurement date.
     When  determining the fair value  measurements  for assets and liabilities
     which are required to be recorded at fair value,  the Plan  considers  the
     principal or most advantageous market in which the Plan would transact and
     the market-based risk measurements or assumptions that market participants
     would  use in  pricing  the asset or  liability,  such as  inherent  risk,
     transfer restrictions and credit risk.

     The Plan applies the following fair value hierarchy, which prioritizes the
     inputs  used to  measure  fair  value  into  three  levels,  and bases the
     categorization within the hierarchy upon the lowest level of input that is
     available and significant to the fair value measurement:

         LEVEL 1 -- Quoted  prices in active  markets for  identical  assets or
         liabilities.

         LEVEL 2 -- Observable  inputs other than Level 1 prices such as quoted
         prices for similar  assets or  liabilities;  quoted  prices in markets
         that are not active;  or other  inputs that are  observable  or can be
         corroborated by observable market data for substantially the full term
         of the assets or liabilities.


                                      14


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 7.   FAIR VALUE MEASUREMENT - CONTINUED

         LEVEL 3 --  Unobservable  inputs  that are  supported  by little or no
         market  activity  and that are  significant  to the fair  value of the
         assets or liabilities.

     The following is a description  of the  valuation  methodologies  used for
     instruments measured at fair value,  including the general  classification
     of such instruments pursuant to the valuation hierarchy.

     MUTUAL FUNDS

         These investments are public investment  vehicles valued using the Net
         Asset Value (NAV) provided by the  administrator  of the fund. The NAV
         is based on the  value of the  underlying  assets  owned by the  fund,
         minus  its  liabilities,  and then  divided  by the  number  of shares
         outstanding.  The  NAV is a  quoted  price  in an  active  market  and
         classified within level 1 of the valuation hierarchy.

     COLLECTIVE INVESTMENT TRUST (STABLE VALUE FUND)

         These investments are public investment  vehicles valued using the NAV
         provided  by the  administrator  of the fund.  The NAV is based on the
         value  of  the  underlying   assets  owned  by  the  fund,  minus  its
         liabilities, and then divided by the number of shares outstanding. The
         NAV is classified  within level 2 of the valuation  hierarchy  because
         the NAV's unit price is quoted on a private market that is not active;
         however,  the unit price is based on underlying  investments which are
         traded on an active market.

     NEXEN INC. COMMON STOCK

         Nexen Inc common stock is valued at the closing price  reported on the
         New York Stock  Exchange  Composite  Listing and is classified  within
         Level 1 of the valuation hierarchy.

     LOANS TO PARTICIPANTS

         Loans to Plan  participants are valued at cost plus accrued  interest,
         which approximates fair value and are classified within Level 3 of the
         valuation hierarchy.


                                      15


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 7.   FAIR VALUE MEASUREMENT - CONTINUED

     Below are the  Plan's  financial  instruments  carried  at fair value on a
     recurring basis by the fair value hierarchy levels described above:



                                                                    As of December 31, 2009
                                           ---------------------------------------------------------------

                                             Quoted Prices
                                               in Active       Significant   Significant
                                              Markets for       Observable   Unobservable
                                           Identical Assets       Inputs        Inputs           Total
                                               (Level 1)        (Level 2)     (Level 3)       Fair Value
                                           ----------------- -------------- ------------- ----------------
                                                                              
       Assets:
         Common stock - Nexen                 $ 16,405,315     $     -        $     -       $ 16,405,315
         Mutual funds
             Bond                                5,669,546           -              -          5,669,546
             Domestic equity                    25,160,337           -              -         25,160,337
             Real estate                         3,129,953           -              -          3,129,953
             International/global               14,199,994           -              -         14,199,994
         Collective investment trusts                -           9,995,303          -          9,995,303
             (Stable value fund)
         Participant loans                           -               -          804,239          804,239
                                           ----------------- -------------- ------------- ----------------
             Total assets                     $ 64,565,145     $ 9,995,303    $ 804,239     $ 75,364,687
                                           ================= ============== ============= ================


                                                                    As of December 31, 2008
                                           ---------------------------------------------------------------

                                             Quoted Prices
                                               in Active       Significant   Significant
                                              Markets for       Observable   Unobservable
                                           Identical Assets       Inputs        Inputs           Total
                                               (Level 1)        (Level 2)     (Level 3)       Fair Value
                                           ----------------- -------------- ------------- ----------------
       Assets:
         Common stock - Nexen                 $ 11,126,459     $     -        $     -       $ 11,126,459
         Mutual funds
             Bond                                2,886,524           -              -          2,886,524
             Domestic equity                    11,430,624           -              -         11,430,624
             Real estate                         1,385,697           -              -          1,385,697
             International/global                5,766,032           -              -          5,766,032
         Collective investment trusts                -           4,528,717          -          4,528,717
             (Stable value fund)
         Money market fund                           -             568,678          -            568,678
         Participant loans                           -               -          808,274          808,274
                                           ----------------  -------------- ------------- ----------------
             Total assets                     $ 32,595,336     $ 5,097,395    $ 808,274     $ 38,501,005
                                           ================  ============== ============= ================



                                      16


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 7.   FAIR VALUE MEASUREMENT - CONTINUED

     The table  below  sets forth a summary of changes in the fair value of the
     Plan's  Level 3  investment  assets and  liabilities  for the years  ended
     December 31, 2009 and 2008:

          Balance, January 1, 2008                                    $ 761,928
          Issuances, Payments, Maturities                                46,346
                                                              ------------------
          Balance, December 31, 2008                                    808,274
          Issuances, Payments, Maturities                                (4,035)
                                                              ------------------
          Balance, December 31, 2009                                  $ 804,239
                                                              ==================


NOTE 8.   DOL INQUIRY

     In 2008 the Department of Labor (DOL) conducted an audit of the Plan. In a
     letter dated May 9, 2009, the  Department of Labor noted several  possible
     violations  and requested  further  information  and comment.  The Company
     responded  to the DOL in a  letter  dated  June 4,  2009  with  additional
     information and explanation of why it believes no violations occurred.  On
     March 4, 2010, the Department of Labor replied to the Company's letter and
     noted all  possible  violations  noted during the audit would be rescinded
     and no violation  occurred based on the responses provided to the original
     findings.



                                      17


                               NEXEN SAVINGS PLAN
                         NOTES TO FINANCIAL STATEMENTS


NOTE 9.   RECONCILIATION OF FINANCIAL STATEMENTS TO SCHEDULE H OF FORM 5500

     The following is a reconciliation of net assets available for benefits and
     changes in net assets available for benefits per the financial  statements
     to Schedule H of Form 5500 as of and for the years ending:



                                                                                      2009             2008
                                                                               --------------  ---------------
                                                                                         
         Net assets available for benefits per financial statements             $ 75,420,223    $  38,771,592
         Adjustment from contract value to fair value not reported
              on Schedule H of Form 5500                                              68,943         (219,680)
                                                                               --------------  ---------------
         Net assets available for benefits per Schedule H of
              Form 5500                                                         $ 75,489,166    $  38,551,912
                                                                               ==============  ===============


         Increase (Decrease) in net assets available for benefits
              per financial statements                                          $ 36,648,631    $ (20,021,728)
         Adjustment from contract value to fair value reported
              on Schedule H of Form 5500                                             288,623         (180,086)
         Transfers of assets into the Plan included in increase
              in net assets available for benefits per financial statements
              but not included in net income per Schedule H of Form 5500         (22,313,374)         (64,116)
                                                                               --------------  ---------------


         Net gain (loss) per Schedule H of Form 5500                            $ 14,623,880    $ (20,265,930)
                                                                               ==============  ===============


     Investments in the common  collective  trust are recorded on the Form 5500
     at fair value but are adjusted to contract  value for financial  statement
     presentation.



                                      18







                             SUPPLEMENTAL SCHEDULE











                               NEXEN SAVINGS PLAN
         SCHEDULE H, LINE 4I - SCHEDULE OF ASSETS (HELD AT END OF YEAR)
                                EIN: 06-0944810
                                PLAN NUMBER 001
                               DECEMBER 31, 2009


(a)                (b)                                     (c)                               (d)         (e)
                                                 Description of Investment including
         Identity of Issuer, borrower             maturity date, rate of investment,                   Current
           lessor, or similar party               collateral, par, or maturity value        Cost #      value
- ---- --------------------------------------  --------------------------------------------- -------  -------------
                                                                                        
PARTICIPANT-DIRECTED INVESTMENTS:

     The Vanguard Group                      Vanguard Total Bond Market
                                                  Net Asset Value $10.35                              $ 5,669,546

     The American Funds Group                Washington Mutual Investors Fund A,
                                                  Net Asset Value $24.64                                7,297,581

     The American Funds Group                EuroPacific Growth Fund A,
                                                  Net Asset Value $38.34                                6,476,852

     American Beacon                         American Beacon Small Cap Value Plan
                                                  Net Asset Value $15.50                                2,493,370

     DWS Investments                         DWS Equity 500 Index Fund,
                                                  Net Asset Value $125.14                               4,831,307

     First Eagle Funds                       First Eagle Overseas Fund A,
                                                  Net Asset Value $19.46                                2,880,109

     Royce Funds                             Royce Value Service Fund,
                                                  Net Asset Value $10.13                                2,668,650

     The American Funds Group                Growth Fund of America A,
                                                  Net Asset Value $27.33                                5,857,423

     Third Avenue Funds                      Third Avenue Value Fund,
                                                  Net Asset Value $46.32                                2,012,006

     American Century Investments            American Century Real Estate Investment Fund,
                                                  Net Asset Value $14.43                                3,129,953

     Oppenheimer Funds                       Oppenheimer Developing Markets Fund A,
                                                  Net Asset Value $28.76                                4,843,033

     Schwab Funds                            Schwab Stable Value Class S,
                                                  Net Asset Value $18.82                                9,995,303

     Bank of America                         Cash                                                         183,602

*    Nexen Inc.                              Nexen Inc. Stock Fund,
                                                (Nexen Inc. Stock, no par,
                                                 Net Asset Value $23.93)                               16,405,315

*    Loans to Participants                   Interest Rates From 4.43% to 9.13%                           804,239
                                                                                                     -------------
                                                                                                     $ 75,548,289
                                                                                                     =============

*   Indicates each identified person/entity known to be party-in-interest.

#   Historical   cost   information   omitted  as  it  is  not   required   for
    participant-directed investments.

    This  supplemental  schedule lists assets held for  investment  purposes at
    December  31,  2009,  as required by the  Department  of Labor's  Rules and
    Regulations for Reporting and Disclosure.



                                       19


                                   SIGNATURES

     THE PLAN.  Pursuant to the requirements of the Securities  Exchange Act of
1934, Nexen  Petroleum  U.S.A. Inc. has  duly  caused  this annual report to be
signed on its behalf by the undersigned hereunto duly authorized.

DATED:  June 23, 2010

                                         NEXEN SAVINGS PLAN

                                         By:  Nexen Petroleum U.S.A. Inc.



                                         By:  /s/ Brian C. Reinsborough
                                              ---------------------------------
                                              Brian C. Reinsborough, President








                               INDEX TO EXHIBITS


        EXHIBIT
        NUMBER                 DESCRIPTION OF EXHIBITS

           1               Consent of Weaver & Tidwell, L.L.P.