<PAGE>

                                                                    Exhibit 10.5

                              EMPLOYMENT AGREEMENT

         This Employment Agreement (this "Agreement") entered into effective as
of November 4, 2003, by and between Marshall L. Munsell (the "Executive"), and
Mission Resources Corporation, a Delaware corporation having its principal place
of business at 1331 Lamar, Suite 1455, Houston, Texas 77010-3039 (the
"Company");

                                  WITNESSETH:

         WHEREAS, The Company wishes to employ the Executive as Senior Vice
President - Land and Land Administration and to perform services incident to
such position for the Company, and the Executive wishes to be so employed by the
Company, all upon the terms and conditions hereinafter set forth:

         NOW THEREFORE, in consideration of the premises and mutual covenants
and obligations herein set forth and for other good and valuable consideration,
the receipt, sufficiency and adequacy of which is hereby acknowledged, accepted
and agreed to, the parties hereto, intending to be legally bound, hereby agree
as follows:

         1. EMPLOYMENT AND TERM. The Company hereby employs the Executive to
serve as Senior Vice President - Land and Land Administration of the Company.
The term of this Agreement (the "Term of this Agreement") shall be effective as
of the date first above written and shall terminate thirty-six (36) months from
the date hereof (the "Termination Date"), unless earlier terminated by either
party hereto in accordance with the provisions of Section 5 hereof; provided,
however, that beginning on the first anniversary date of the date hereof and on
each anniversary date of the date hereof thereafter, the Term of this Agreement
shall be automatically extended one additional year unless either party give
written notice to the other at least six months prior to such anniversary of the
date hereof that the Term of this Agreement shall cease to be so extended.
During the Term of this Agreement, the terms of employment shall be as set forth
herein unless modified by the Executive and the Company in accordance with the
provisions of Section 12 hereof. The Executive hereby agrees to accept such
employment and to perform the services specified herein, all upon the terms and
conditions hereinafter set forth.

         2. POSITION AND RESPONSIBILITIES. The Executive shall serve as Senior
Vice President - Land and Land Administration of the Company and shall report
to, and be subject to the general direction of the Chairman and Chief Executive
Officer of the Company. The Executive shall have other obligations, duties,
authority and power to do all acts and things as are customarily done by a
person holding the same or equivalent position or performing duties similar to
those to be performed by executives in corporations of similar size to the
Company and shall perform such managerial duties and responsibilities for the
Company which are not inconsistent with his position as may reasonably be
assigned to him by the Chairman and Chief Executive Officer and/or the Board of
Directors of the Company (or a committee thereof). Unless otherwise agreed to by
the Executive, the Executive shall be based at the Company's principal executive
offices located in the greater Houston, Texas metropolitan area.

         3. EXTENT OF SERVICE. The Executive shall devote his full business time
and attention to the business of the Company. During the Term of this Agreement,
Executive shall devote his best efforts and skills to the business and interests
of Company, do his utmost to


                                       1
<PAGE>

further enhance and develop Company's best interests and welfare, and endeavor
to improve his ability and knowledge of Company's business, in an effort to
increase the value of his services for the mutual benefit of the parties hereto.
During the Term of this Agreement, it shall not be a violation of this Agreement
for Executive to (i) serve on any corporate board or committee thereof with the
approval of the Board, (ii) serve on any civic or charitable boards or
committees (except for boards or committees of a competing business unless
approved by the Board), (iii) deliver lectures, fulfill teaching or speaking
engagements, (iv) testify as a witness in litigation involving a former employer
or (v) manage personal investments; provided, however, any such activities must
not materially interfere with performance of Executive's responsibilities under
this Agreement.

         4. COMPENSATION.

         (a) In consideration of the services to be rendered by the Executive to
the Company, the Company will pay the Executive a salary ("Salary") of $200,000
per year during the Term of this Agreement. Such Salary will be payable in
conformity with the Company's prevailing practice for executives' compensation
as such practice shall be established or modified from time to time. Salary
payments shall be subject to all applicable federal and state withholding,
payroll and other taxes. From time to time during the Term of this Agreement,
the amount of the Executive's Salary may be increased by, and at the sole
discretion of, the Compensation Committee of the Company's Board of Directors
(the "Compensation Committee"), which shall review the Executive's Salary no
less regularly than annually.

         (b) The Company has granted the Executive on November 4, 2003 an option
to purchase 125,000 shares of common stock of the Company at an exercise price
per share of $2.61 ("Option"). Such Option shall vest 33.4% on the date of grant
and 33.3% on each of the first and second anniversary date of grant. The term of
the Option shall be ten years from the date of grant subject to the provisions
of paragraphs 5(f)(i) and 5(g) hereof. Additional grants of options will be
considered by the Compensation Committee on an annual basis based on a review of
the Executive's performance.

         (c) The Executive will be considered for an annual cash and/or stock
bonus based on an evaluation of his performance by the Compensation Committee.
Any such bonus will be at the sole discretion of the Compensation Committee.

         (d) During the term of this Agreement, the Company shall pay or
reimburse the Executive for all reasonable out-of-pocket expenses for travel,
meals, hotel accommodations, entertainment and the like incurred by him in
connection with the business of the Company upon submission by him and approval
of an appropriate statement documenting such expenses as required by the
Company's policy and the Internal Revenue Code of 1986, as amended (the "Code").
In addition, the Audit Committee of the Board of Directors shall review all such
expense reports on a quarterly basis.

         (e) The Executive shall be entitled to four (4) weeks of paid vacation
during each calendar year during the term of this Agreement. Vacation shall
accrue on the first day of each calendar year. The use of such vacation shall be
governed by and administered in accordance with the Company's vacation policy as
in effect from time to time.



                                       2
<PAGE>

         (f) During the term of this Agreement, the Executive shall be entitled
to participate in and to receive all rights and benefits under any life,
disability, medical and dental, health and accident and profit sharing or
deferred compensation plans and such other plan or plans as may be implemented
by the Company during the term of this Agreement. The Executive shall also be
entitled to participate in and to receive all rights and benefits under any plan
or program adopted by the Company for any other or group of other executive
employees of the Company, including without limitation, the rights and benefits
under the directors' and officers' liability insurance in place from time to
time under the Company's insurance program for the directors and officers of the
Company.

         (g) During the term of this agreement, the Executive shall be entitled
to receive a car allowance of $500.00 per month, and one parking space shall be
provided to the Executive by the Company.

         (h) The Company shall pay one club initiation fee of up to $25,000.00
and the base monthly dues applicable thereto, not to exceed $400.00 per month.

         5. TERMINATION.

         (a) Termination by Company; Discharge for Cause. The Company shall be
entitled to terminate this Agreement and the Executive's employment with the
Company at any time and for whatever reason; or at any time for "Cause" (as
defined below) by written notice to the Executive. Termination of the
Executive's employment by the Company shall constitute a termination for "Cause"
if such termination is for one or more of the following reasons: (i) the willful
failure or refusal of the Executive to render services to the Company in
accordance with his obligations under this Agreement, including, without
limitation, the willful failure or refusal of the Executive to comply with the
work rules, policies, procedures, and directives as established by the Chairman
and Chief Executive Officer and the Board of Directors and consistent with this
Agreement; such failure or refusal to be uncured and continuing for a period of
not less than fifteen (15) days after notice outlining the situation is given by
the Company to the Executive; (ii) the commission by the Executive of an act of
fraud or embezzlement; (iii) the commission by the Executive of any other action
with the intent to injure the Company; (iv) the Executive having been convicted
of a felony or a crime involving moral turpitude; (v) the Executive having
misappropriated the property of the Company; (vi) the Executive having engaged
in personal misconduct which materially injures the Company; or (vii) the
Executive having willfully violated any law or regulation relating to the
business of the Company which results in material injury to the Company. In the
event of the Executive's termination by the Company for Cause hereunder, the
Executive shall be entitled to no severance or other termination benefits except
for any unpaid Salary accrued through the date of termination. A termination of
this Agreement by the Company without Cause pursuant to this Section 5(a) (which
shall include the decision by the Company to not renew the Term of this
Agreement for any additional one year periods as provided in Section 1 above)
shall entitle the Executive to the Severance Payment and other benefits
specified in Section 5(f) or (g), hereof, as the case may be.

         (b) Death. If the Executive dies during the term of this Agreement and
while in the employ of the Company, this Agreement shall automatically terminate
and the Company shall have no further obligation to the Executive or his estate
except that the Company shall pay to the



                                       3
<PAGE>

Executive's estate that portion of his Salary and benefits accrued through the
date of death. All such payments to the Executive's estate shall be made in the
same manner and at the same time as the Executive's Salary.

         (c) Disability. If during the term of this Agreement, the Executive
shall be prevented from performing his duties hereunder for a period of 90 days
by reason of disability, then the Company, on 30 days' prior notice to the
Executive, may terminate this Agreement. For purposes of this Agreement, the
Executive shall be deemed to have become disabled when the Board of Directors of
the Company, upon verification by a physician designated by the Company, shall
have determined that the Executive has become physically or mentally unable
(excluding infrequent and temporary absences due to ordinary illness) to perform
the essential functions of his duties under this Agreement with reasonable
accommodation. In the event of a termination pursuant to this paragraph (c), the
Company shall be relieved of all its obligations under this Agreement, except
that the Company shall pay to the Executive or his estate in the event of his
subsequent death, that portion of the Executive's Salary and benefits accrued
through the date of such termination. All such payments to the Executive or his
estate shall be made in the same manner and at the same time as his Salary would
have been paid to him had he not become disabled.

         (d) Termination for Good Reason. The Executive shall be entitled to
terminate this Agreement and his employment with the Company at any time upon
thirty (30) days written notice to the Company for "Good Reason" (as defined
below). The Executive's termination of employment shall be for "Good Reason" if
such termination is a result of any of the following events:

                  (i) The Executive is assigned any responsibilities or duties
         materially inconsistent with his position, duties, responsibilities and
         status with the Company as in effect at the date of this Agreement or
         as may be assigned to the Executive pursuant to Section 2 hereof; or
         his title or offices as in effect at the date of this Agreement or as
         the Executive may be appointed or elected to in accordance with Section
         2 are changed; or the Executive is required to report to or be directed
         by any person other than the Chairman and Chief Executive Officer and
         the Board of Directors of the Company;

                  (ii) there is a reduction in the Salary (as such Salary shall
         have been increased from time to time) payable to the Executive
         pursuant to Section 4(a) hereof unless such reduction is applicable to
         all senior executives of the Company;

                  (iii) failure by the Company or any successor to the Company
         or its assets to continue to provide to the Executive any material
         benefit, bonus, profit sharing, incentive, remuneration or compensation
         plan, stock ownership or purchase plan, stock option plan, life
         insurance, disability plan, pension plan or retirement plan in which
         the Executive was entitled to participate in as at the date of this
         Agreement or subsequent thereto, or the taking by the Company of any
         action that materially and adversely affects the Executive's
         participation in or materially reduces his rights or benefits under or
         pursuant to any such plan or the failure by the Company to increase or
         improve such rights or benefits on a basis consistent with practices in
         effect prior to the date of this Agreement or with practices
         implemented and subsequent to the date of this Agreement with respect
         to the


                                       4
<PAGE>

         executive employees of the Company generally, which ever is more
         favorable to the Executive, but excluding such action that is required
         by law;

                  (iv) without Executive's consent, the Company requires the
         executive to relocate to any city or community other than one within a
         fifty (50) mile radius of the greater Houston, Texas metropolitan area,
         except for required travel on the Company's business to an extent
         substantially consistent with the Executive's business obligations
         under this Agreement; or

                  (v) there is any material breach by the Company of any
         provision of this Agreement.

                  (vi) Upon the Executive's termination of this Agreement for
         Good Reason, the Executive shall be entitled to the Severance Payment
         and other benefits specified in Section 5(f) hereof.

         (e) Voluntary Termination. Notwithstanding anything to the contrary
herein, the Executive shall be entitled to voluntarily terminate this Agreement
and his employment with the Company at his pleasure upon sixty (60) days written
notice to such effect. In such event, the Executive shall not be entitled to any
further compensation other than any unpaid Salary and benefits accrued through
the date of termination. At the Company's option, the Company may pay to the
Executive the salary and benefits that the Executive would have received during
such sixty (60) day period in lieu of requiring the Executive to remain in the
employment of the Company for such sixty (60) day period.

         (f) Termination Benefits Upon Involuntary Termination or Termination
for Good Reason. In the event that (i) the Company terminates this Agreement and
the Executive's employment with the Company for any reason other than for Cause
(as defined in Section 5(a) hereof) or the death or disability (as defined in
Section 5(c) hereof) of the Executive, or (ii) the Executive terminates this
Agreement and his employment with the Company for Good Reason (as set forth in
Section 5(d) hereof), then the Company shall pay the Executive, within thirty
(30) days after the date of termination, an amount (the "Severance Payment")
equal to (x) two (2) times the Executive's highest annual Salary in existence at
any time during the last two (2) years of employment immediately preceding the
date of termination, and (y) a prorata portion (based on the portion of the
calendar year that the Executive served hereunder prior to such termination) of
the annual bonus which would have been paid to the Executive for the full year
during which such termination occurred, minus applicable withholding and
authorized salary reductions (the "Severance Payment"). In addition, following
other such termination, the Executive shall be entitled to the following
benefits (collectively, the "Additional Benefits");

                  (i) immediate vesting of any of the Executive's outstanding
         options to purchase securities of the Company which were not vested by
         their own terms on the date of termination and the extension of the
         Executive's right to exercise all the Executive's options to purchase
         securities of the Company for a period equal to the lesser of (A) one
         (1) year following the date of termination or (B) the remaining term of
         the applicable option;


                                       5
<PAGE>

                  (ii) continued coverage, at the Company's cost, under the
         Company's group health plan for the applicable coverage period under
         the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended
         ("COBRA") but only if Executive elects such COBRA continuation in
         accordance with the time limits and in the applicable COBRA
         regulations; and

                  (iii) an amount, in cash, equal to the sum of (A) any
         unreimbursed expenses incurred by the Executive in the performance of
         his duties hereunder and in compliance with Company policy through the
         date of termination, plus (B) any accrued and unused vacation time or
         other unpaid benefits as of the date of termination; and

                  (iv) Company shall cause Executive to be covered by any policy
         or contract of insurance obtained by it to insure its directors and
         officers against personal liability for acts or omissions in connection
         with service as an officer or director of Company or service in other
         capacities at the request of the company. The coverage provided to
         Executive pursuant to this paragraph shall be of a scope and on terms
         and conditions at least as favorable as the most favorable coverage
         provided to any other officer or director of Company (or any
         successor). In addition, the Company agrees that the Indemnification
         Agreement entered into by and between the Company and the Executive, as
         well as all other rights to which Executive is entitled with regard to
         indemnification and advancement of expenses, whether by virtue of the
         Company's certificate of incorporation, bylaws or otherwise, will
         remain in full force and effect, in accordance with its terms.

         The parties agree that, because there can be no exact measure of the
damages which would occur to the Executive as a result of termination of
employment, such payments contemplated in this Section 5(f) shall be deemed to
constitute liquidated damages and not a penalty and the Company agrees that the
Executive shall not be required to mitigate his damages. The termination
compensation in this Section 5(f) shall be paid only if the Executive executes a
termination agreement releasing all legally waivable claims arising from the
Executive's employment.

         (g) Termination and Benefits upon a Change in Control. In the event of
a Change in Control, as defined in this Section 5(g), then in lieu of the
Severance Payment contained in Section 5(f) hereof, if the Executive is
terminated without Cause or the Executive terminates his employment for Good
Reason within the twelve (12) month period immediately following a Change in
Control the Company shall pay to the Executive a lump sum amount equal to: (x)
two (2) times the Executive's highest annual salary paid during the last two (2)
years immediately preceding the date of termination, and (y) a prorata portion
(based on the portion of the calendar year that the Executive served hereunder
prior to such termination) of the annual bonus which would have been paid to the
Executive for the full year during which such termination occurred, which in no
event will be less than one-half of the Executive's then current Salary, minus
applicable withholding and authorized salary reductions (the "Payment"). In the
event that the excise tax relating to "parachute payments" under Section 280G of
the Code applies to the Payment, then the Company shall pay the Executive an
additional payment in an amount such that, after payment of federal income taxes
(but not the excise tax) on such additional payment, the Executive receives an
additional amount equal to the excise tax originally imposed on the



                                       6
<PAGE>


Payment. The Executive shall also be entitled to receive the Additional
Benefits. "Change of Control" means or shall be deemed to have occurred if and
when: (i) any "person" or "group" (as such terms are used in Section 13(d) and
14(d) of the Exchange Act) is or becomes the "beneficial owner" (as defined in
Rule 13d-3 under the Exchange Act), directly or indirectly, of more than 50% of
the total voting power of the outstanding voting stock of the Company; (ii) the
Company is merged with or into or consolidated with another Person and,
immediately after giving effect to the merger or consolidation, (a) less than
50% of the total voting power of the outstanding voting stock of the surviving
or resulting Person is then "beneficially owned" (within the meaning of Rule
13d-3 under the Exchange Act) in the aggregate by the stockholders of the
Company immediately prior to such merger or consolidation, and (b) any "person"
or "group" (as defined in Section 13(d)(3) or 14(d)(2) of the Exchange Act) has
become the direct or indirect "beneficial owner" (as defined in Rule 13d-3 under
the Exchange Act) of more than 50% of the total voting power of the voting stock
of the surviving or resulting Person; (iii) the Company sells, assigns, conveys,
transfers, leases or otherwise disposes of all or substantially all of the
Company assets (either in one transaction or a series of related transactions);
(iv) the liquidation or dissolution of the Company; or (v) during any
consecutive two-year period individuals who at the beginning of such period
constituted the Board of Directors of the Company (together with any new
directors whose election by such Board of Directors or whose nomination by the
Board of Directors for election by the stockholders of the Company was approved
by a vote of a majority of the directors then still in office who were either
directors at the beginning of such period or whose election or nomination for
election was previously so approved) cease for any reason to constitute a
majority of the Board of Directors of the Company then in office.

         (h) Survival. Notwithstanding the termination of this Agreement under
this Section 5, the provisions of Sections 7 and 8 of this Agreement, and all
other provisions hereof which by their terms are to be performed following the
termination hereof shall survive such termination and be continuing obligations.

         6. CONSENT AND WAIVER BY THIRD PARTIES. The Executive hereby represents
and warrants that he has obtained all necessary waivers and/or consents from
third parties as to enable him to accept employment with the Company on the
terms and conditions set forth herein and to execute and perform this Agreement
without being in conflict with any other agreement, obligations or understanding
with any such third party.

         7. CONFIDENTIAL INFORMATION. The Executive acknowledges that in the
course of his employment with the Company, he has received and will receive
access to confidential information of a special and unique value concerning the
Company and its business, including, without limitation, trade secrets,
know-how, lists of customers, employee records, books and records relating to
operations, costs or providing service and equipment, operating and maintenance
costs, pricing criteria and other confidential information and knowledge
concerning the business of the Company and its affiliates (hereinafter
collectively referred to as "information") which the Company desires to protect.
The Executive acknowledges that such information is confidential and the
protection of such confidential information against unauthorized use or
disclosure is of critical importance to the Company. The Executive agrees that
he will not reveal such information to any one outside the Company. The
Executive further agrees that during the term of this Agreement and thereafter
he will not use or disclose such



                                       7
<PAGE>

information. Upon termination of his employment hereunder, the Executive shall
surrender to the Company all papers, documents, writings and other property
produced by him or coming into his possession by or through his employment
hereunder and relating to the information referred to in this Section 7, and the
Executive agrees that all such materials will at all times remain the property
of the Company. The obligation of confidentiality, non-use and non-disclosure
of know-how set forth in this Section 7 shall not extend to know-how (i) which
was in the public domain prior to disclosure by the disclosing party, (ii) which
comes into the public domain other than through a breach of this Agreement,
(iii) which is disclosed to the Executive after the termination of this
Agreement by a third party having legitimate possession thereof and the
unrestricted right to make such disclosure, or (iv) which is necessarily
disclosed in the course of the Executive's performance of his duties to the
Company as contemplated in this Agreement. The agreements in this Section 7
shall survive the termination of this Agreement.

         8. NO SOLICITATION. To support the agreements contained in Section 7
hereof, from the date hereof and for a period twelve (12) months after the
Executive's employment with the Company is terminated for any reason, the
Executive shall not, either directly or indirectly, through any person, firm,
association or corporation with which the Executive is now or may hereafter
become associated, (i) solicit any then current employee of the Company or its
affiliates (except through ads or notices offering employment that are published
or otherwise made publicly available), or (ii) use in any competition,
solicitation or marketing effort any information as to which the Executive has a
duty of confidential treatment under paragraph 7 above.

         9. NOTICES. All notices, requests, consents and other communications
under this Agreement shall be in writing and shall be deemed to have been
delivered on the date personally delivered or on the date mailed, postage
prepaid, by certified mail, return receipt requested, or telegraphed and
confirmed if addressed to the respective parties as follows:

                If to the Executive:     Marshall L. Munsell
                                         c/o Mission Resources Corporation
                                         1331 Lamar, Suite 1455
                                         Houston, Texas 77010-3039

                If to the Company:       Mission Resources Corporation
                                         1331 Lamar, Suite 1455
                                         Houston, Texas 77010-3039
                                         Attn: Chairman, Compensation Committee

Either party hereto may designate a different address by providing written
notice of such new address to the other party hereto.

         10. SPECIFIC PERFORMANCE. The Executive acknowledges that a remedy at
law for any breach or attempted breach of Section 7 or 8 of this Agreement will
be inadequate, agrees that the Company shall be entitled to specific performance
and injunctive and other equitable relief in case of any such a breach or
attempted breach, and further agrees to waive any requirement of the securing or
posting of any bond in connection with the obtaining of any such injunctive or
any other equitable relief.


                                       8
<PAGE>

         11. WAIVERS AND MODIFICATIONS. This Agreement may be modified, and the
rights and remedies of any provision hereof may be waived, only in accordance
with this Section 11. No modifications or waiver by the Company shall be
effective without the consent of at least a majority of the Compensation
Committee of the Board of Directors then in office at the time of such
modification or waiver. No waiver by either party of any breach by the other or
any provision hereof shall be deemed to be a waiver of any later or other breach
thereof or as a waiver of any other provision of this Agreement. This Agreement
sets forth all the terms of the understandings between the parties with
reference to the subject matter set forth herein and may not be waived, changed,
discharged or terminated orally or by any course of dealing between the parties,
but only by an instrument in writing signed by the party against whom any
waiver, change, discharge or termination is sought.

         12. GOVERNING LAW. This Agreement shall be construed in accordance with
the laws of the State of Texas.

         13. SEVERABILITY. In case of one or more of the provisions contained in
this Agreement for any reason shall be held to be invalid, illegal or
unenforceable in any respect, such invalidity, illegality or unenforceability
shall not affect any other provision of this Agreement, but this Agreement shall
be construed as if such invalid, illegal or unenforceable provisions had
never contained herein.

         14. ARBITRATION. In the event that a dispute or controversy should
arise between the Executive and the Company as to the meaning or application of
any provision, term or condition of this Agreement, such dispute or controversy
shall be settled by binding arbitration in Houston, Texas and for said purpose
each of the parties hereto hereby expressly consents to such arbitration in such
place. Such arbitration shall be conducted in accordance with the existing rules
and regulations of the American Arbitration Association governing commercial
transactions. The expense of the arbitrator shall be borne by the Company.

         IN WITNESS WHEREOF, each of the parties hereto has executed this
Agreement as of the date and year first above written.


                             COMPANY:

                             MISSION RESOURCES CORPORATION



                             By:
                                -----------------------------------------------

                             Name:
                                  ---------------------------------------------

                             Title:
                                   --------------------------------------------



                             EXECUTIVE:

                             --------------------------------------------------
                                 Marshall L. Munsell



                                       9