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                                                                    EXHIBIT 10.1
                                PROMISSORY NOTE


$170,600.00                     Houston, Texas                      July 1, 1997


         1.      FOR VALUE RECEIVED, the undersigned, Frank A. Pici, an
individual residing at 6306 Wagner Way, Sugar Land, Texas  77479 ("Maker"),
hereby promises to pay to the order of Mariner Energy, Inc., a Delaware
corporation (the "Payee"), in Houston, Harris County, Texas, at 580 Westlake
Boulevard, Suite 1300, Houston, Texas  77079, on or before July 1, 2002 (the
"Maturity Date"), in lawful money of the United States of America, the
principal amount of ONE HUNDRED SEVENTY THOUSAND SIX HUNDRED AND NO/100 DOLLARS
($170,600.00), together with interest on the unpaid balance of said principal
amount from time to time remaining outstanding, from the date hereof until
maturity (howsoever such maturity shall occur), in like money, at said office,
at a rate per annum equal to the lesser of (a) the Note Rate, and (b) the
Maximum Rate.

         2.      All past due principal of and interest on this Note shall bear
interest from the due date thereof (whether by acceleration or otherwise) until
paid at a per annum rate equal to the Maximum Rate.

         3.      Accrued unpaid interest on the outstanding principal balance
hereof shall be due and payable quarterly by Maker to Payee on the last
Business Day (as hereinafter defined) of each calendar quarter, commencing
September 30, 1997.  The outstanding principal balance of this Note shall be
due and payable on the Maturity Date, upon which day all outstanding principal
shall be immediately due and payable.  The foregoing notwithstanding, all
unpaid accrued interest on this Note, and the outstanding unpaid principal
balance hereof, shall be immediately due and payable in full upon the maturity
of the principal of this Note, whether by acceleration or otherwise.

         4.      Maker shall have the right and privilege of prepaying this
Note, in whole or in part, at any time or from time to time without premium or
penalty or notice to the holder hereof.  All amounts prepaid shall be applied
first to earned, accrued and unpaid interest and the balance, if any, shall be
applied to the payment of the principal installments in inverse order of
maturity.

         5.      The terms set forth below shall have the meanings assigned to
such terms as used in this Note:

                 "Applicable Law" shall mean the law in effect from time to
         time and applicable to the transactions between Payee and Maker
         pursuant to this Note which lawfully permits the charging and
         collection of the highest permissible lawful non-usurious rate of
         interest on such transactions,





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         including laws of the State of Texas, and to the extent controlling
         and providing for a higher lawful rate of interest, laws of the United
         States of America.  It is intended that Article 1.04, Title 79,
         Revised Civil Statutes of Texas, 1925, as amended, shall be included
         in the laws of the State of Texas in determining Applicable Law; and
         for the purpose of applying said Article 1.04, the interest ceiling
         applicable to such transactions under said Article 1.04 shall be the
         indicated (weekly) rate ceiling from time to time in effect.

                 "Business Day" shall mean any day on which banks are open for
         general banking business in the State of Texas, other than on
         Saturday, Sunday, a legal holiday or any other day on which banks in
         the State of Texas are required or authorized by law or executive
         order to close.

                 "Maximum Rate" shall mean the maximum lawful non-usurious rate
         of interest, if any, which under Applicable Law Payee is permitted to
         charge Maker on the loan evidenced by this Note from time to time.
         If, however, during any period interest accruing on this Note is not
         limited to any maximum lawful non-usurious rate of interest under
         Applicable Law, then during each such period the "Maximum Rate" shall
         be equal to a per annum rate of 10% plus the Note Rate.

                 "Note Rate" shall mean, for each calendar quarter during the
         term of this Note, a per annum rate of interest equal to one and
         one-quarter percent (1 1/4%) plus the London Interbank Offered Rate
         ("LIBOR") for the last month of such calendar quarter as reported in
         the Wall Street Journal on the first Business Day of such calendar
         quarter.

         6.      If any one of the following events shall occur and be
continuing (an "Event of Default"):

                 (a)      Maker shall fail to pay timely when due, the
         principal of, or accrued unpaid interest on, this Note or any other of
         the obligations hereunder; or

                 (b)      Maker shall breach any representation or warranty
         made by Maker in any statement furnished concurrently herewith or
         hereafter to Payee by or on behalf of Maker; or

                 (c)(i)   Default shall be made in the due observance or
         performance of, or compliance with, any of the covenants or agreements
         contained herein or (ii) the occurrence of any event or circumstance
         which constitutes an "event of default" under any security agreement
         or other instrument securing payment hereof; or





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                 (d)      Maker shall (i) die, resign from employment by Payee,
         be disabled so as to be unable for more than three consecutive months
         to work full time in the employ of Payee, or shall no longer be
         employed by Payee for any other reason (including, without limiting
         the generality of the foregoing, termination of employment by Maker
         for cause or without cause) as an officer of Payee, or (ii) apply for
         or consent to the appointment of a receiver, trustee, custodian or
         liquidator of Maker or of all or a substantial part of Maker's
         property, or (iii) generally fail to pay Maker's debts as they come
         due in the ordinary course of business, or (iv) commence, or file an
         answer admitting the material allegations of or consenting to, or
         default in a petition filed against it in, any case, proceeding or
         other action under any existing or future law of any jurisdiction,
         domestic or foreign, relating to bankruptcy, insolvency,
         reorganization or relief of debtors, or seeking to have an order for
         relief entered with respect to Maker under the federal Bankruptcy Code
         11 USC Section 101 et. seq., or seeking reorganization, arrangement,
         adjustment, winding-up, liquidation, composition or the similar relief
         with respect to Maker or Maker's debt; or

                 (e)      A receiver, conservator, liquidator, custodian or
         trustee of Maker or any of Maker's property is appointed by the order
         or decree of any court or agency or supervisory authority having
         jurisdiction; or Maker obtains an order for relief under the federal
         Bankruptcy Code 11 USC Section 101 et. seq.; or any of the property of
         Maker is sequestered by court order; or a petition is filed or a
         proceeding is commenced against Maker under any bankruptcy,
         reorganization, arrangement, insolvency, readjustment of debt or
         liquidation law of any jurisdiction, whether now or hereafter in
         effect; or

                 (f)(i)   Any event or condition occurs which results in, or
         permits the forfeiture by Maker of Maker's material rights, benefits
         or privileges under any indenture, mortgage, deed of trust, promissory
         note, loan agreement, note agreement or any other material agreement
         or undertaking, which continues unremedied for any applicable cure
         period; or (ii) the occurrence of any event, circumstance, or
         condition which, after any applicable cure or notice period or lapse
         of time, or both, would constitute a default under any material
         agreement, contract, promissory note, loan agreement, indenture, lien
         instrument or the like to which Maker is a party or by which any of
         Maker's property is subject, which continues unremedied for any
         applicable cure period, whether or not a party thereto exercises any
         of its rights and remedies with respect to such default; or

                 (g)      The levy or execution of any attachment, execution or
         other process against any material part of the collateral (if any)
         securing this Note or any other material property or interest in
         property of Maker,




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         which is not timely and completely stayed by appropriate proceedings
         and/or bonding requirements; or

                 (h)      Any court shall find or rule, or Maker shall assert
         or claim, (i) that Payee does not have a valid, perfected, enforceable
         lien and security interest in the collateral (if any) securing this
         Note, or (ii) that this Agreement or any of the loan documents
         executed in connection herewith does not or will not constitute the
         legal, valid, binding and enforceable obligations of the party or
         parties (as applicable) thereto, or (iii) that any person has a
         conflicting or adverse lien, claim or right in, or with respect to,
         the collateral (if any) securing this Note or any material portion
         thereof; or

                 (i)      The rendering of any judgment or judgments against
         Maker for the payment of money in excess of $10,000, in the aggregate,
         which remains unsatisfied and in effect for any period of 10
         consecutive days without a stay of execution; or

                 (j)      Maker shall have concealed, removed, or permitted to
         be concealed or removed, any part of Maker's property, with intent to
         hinder, delay or defraud Maker's creditors or any of them, or made or
         suffered a transfer of any of Maker's property which may be fraudulent
         under any bankruptcy, fraudulent conveyance or similar law; or shall
         have made any transfer of Maker's property to or for the benefit of a
         creditor at a time when other creditors similarly situated have not
         been paid; or shall have suffered or permitted, while insolvent, any
         creditor to obtain a lien upon any of Maker's property through legal
         proceedings or distraint or other process which is not vacated within
         10 days from the date thereof; or

                 (k)      Any material adverse change shall occur in the
         business, assets or condition (financial or otherwise) of Maker; or

                 (l)      Payee at any time shall, in Payee's sole and absolute
         discretion, consider the payment of this Note to be insecure or any
         part of the collateral (if any) securing this Note to be unsafe,
         insecure or insufficient and Maker shall not upon demand by Payee
         furnish other collateral or make payment, satisfactory to Payee;

then the Payee, at its option, may declare the unpaid principal portion of this
Note to be forthwith due and payable, whereupon the said portion of this Note
and all accrued, earned and unpaid interest shall become immediately due and
payable by Maker without demand, presentment for payment, notice of
non-payment, protest, notice of protest, notice of intent to accelerate
maturity, notice of acceleration of maturity or any other notice of any kind to
Maker, or any other person liable hereon or with respect hereto, all of which
are hereby expressly waived by Maker and each other person liable hereon or
with respect hereto, anything contained herein or in any other documents or




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instruments to the contrary notwithstanding; and upon the happening of any
Event of Default referred to in paragraphs (e) or (f), the unpaid principal
portion of this Note and all other interest on this Note then accrued, earned
and unpaid shall become automatically due and payable by Maker without demand,
presentment for payment, notice of nonpayment, protest, notice of protest,
notice of intent to accelerate maturity, notice of acceleration of maturity or
any other notice of any kind to Maker or any other person liable hereon or with
respect hereto, all of which are expressly waived by Maker and each other
Person liable hereon or with respect hereto, anything contained herein or in
any document or instrument to the contrary notwithstanding. Further, upon the
occurrence of any default or event of default, Payee shall have all other
rights and remedies as set forth herein and in the other documents (if any)
securing this Note and as otherwise provided at law or in equity, all such
rights and remedies being cumulative, including, but without limitation, the
right, without prior notice to Maker or any other person liable with respect
hereto, to set-off and apply any indebtedness at any time owing by Payee to, or
for the credit or account of, Maker against any indebtedness owed to Payee by
Maker, irrespective of whether or not Payee shall have made demand under this
Note or any other instrument securing this Note, and although this Note may not
then be matured; provided, that any exercise of said set-off by Payee shall be
subsequently followed by notice from Payee to Maker of such right exercised,
but the failure to give such notice shall in no manner affect the right of
Payee in respect to set-offs and corresponding applications of funds.

         7.      Maker shall, upon demand by Payee, promptly pay to Payee any
and all costs and expenses, including legal expenses, collections costs and
attorneys' fees (whether or not legal proceedings are instituted including,
without limitation, legal expenses and reasonable attorneys' fees in connection
with any bankruptcy proceedings), incurred or paid by Payee in protecting or
enforcing Payee's rights hereunder.  Without limiting the generality of the
foregoing, if this Note is collected by suit or through the Bankruptcy Court,
or any judicial proceeding, or if this Note is not paid at maturity, however
such maturity may be brought about, and it is placed in the hands of an
attorney for collection (whether or not legal proceedings are instituted), then
Maker agrees to pay, in addition to all other amounts owing hereunder, the
collection costs and reasonable attorneys' fees of the holder hereof.

         8.      The records of Payee shall constitute rebuttably presumptive
evidence of the principal and earned, accrued and unpaid interest remaining
outstanding on this Note.

         9.      It is the intent of Payee and Maker in the execution and
performance of this Note to remain in strict compliance with Applicable Law
from time to time in effect.  In furtherance thereof, Payee and Maker stipulate
and agree that none of the terms and provisions contained in this Note shall
ever be construed to create a contract to pay for the use, forbearance or
detention of money with interest at a rate or in an amount in excess of the
Maximum Rate or amount of interest permitted to be charged under Applicable
Law.  For purposes of this Note "interest" shall include the aggregate of all
charges which constitute interest under Applicable Law that are contracted for,




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charged, reserved, received or paid under this Note.  Maker shall never be
required to pay unearned interest and shall never be required to pay interest
at a rate or in an amount in excess of the Maximum Rate or amount of interest
that may be lawfully charged under Applicable Law, and the provisions of this
paragraph shall control over all other provisions of this Note, and of any
other instrument pertaining to or securing this Note, which may be in actual or
apparent conflict herewith.  If this Note is prepaid, or if the maturity of
this Note is accelerated for any reason, or if under any other contingency the
effective rate or amount of interest which would otherwise be payable under
this Note would exceed the Maximum Rate or amount of interest Payee or any
other holder of this Note is allowed by Applicable Law to charge, contract for,
take, reserve or receive, or in the event Payee or any holder of this Note
shall charge, contract for, take, reserve or receive monies that are deemed to
constitute interest which would, in the absence of this provision, increase the
effective rate or amount of interest payable under this Note to a rate or
amount in excess of that permitted to be charged, contracted for, taken,
reserved or received under Applicable Law then in effect, then the principal
amount of this Note or the amount of interest which would otherwise be payable
under this Note or both shall be reduced to the amount allowed under Applicable
Law as now or hereinafter construed by the courts having jurisdiction, and all
such moneys so charged, contracted for, taken, reserved or received that are
deemed to constitute interest in excess of the Maximum Rate or amount of
interest permitted by Applicable Law shall immediately be returned to or
credited to the account of Maker upon such determination.  Payee and Maker
further stipulate and agree that, without limitation of the foregoing, all
calculations of the rate or amount of interest contracted for, charged, taken,
reserved or received under this Note which are made for the purpose of
determining whether such rate or amount exceeds the Maximum Rate or amount,
shall be made to the extent not prohibited by Applicable Law, by amortizing,
prorating, allocating and spreading during the period of the full stated term
of this Note, all interest at any time contracted for, charged, taken, reserved
or received from Maker or otherwise by Payee or any other holder of this Note.

         10.     Maker and all sureties, endorsers and guarantors (if any) of
this Note waive demand, presentment for payment, notice of non-payment,
protest, notice of protest, notice of intent to accelerate maturity, notice of
acceleration of maturity and all other notice, filing of suit and diligence in
collecting this Note or enforcing any of the security herefor, and agree to any
substitution, exchange or release of any such security, the release of any
party primarily or secondarily liable hereon and further agree that it will not
be necessary for any holder hereof, in order to enforce payment of this Note,
to first institute suit or exhaust its remedies against any security herefor,
and consent to any one or more extensions or postponements of time of payment
of this Note on any terms or any other indulgences with respect hereto, without
notice thereof to any of them.

         11.     This Note is secured by all security agreements, collateral
assignments and lien instruments (if any) executed by the Maker in favor of
Payee, or executed by any other party as security for this Note, including any
executed prior to, simultaneously




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with, or after the date of this Note and including, without limitation, that
certain Security Agreement of even date herewith by Maker in favor of Payee.

         12.     Maker hereby irrevocably directs Payee to apply and set off,
against the accrued unpaid interest hereon and the outstanding unpaid principal
balance hereof, all deferred compensation and other payments and amounts due
and payable from Payee to Maker on or after the date hereof.  It is Maker's
intention hereby to convey, assign and transfer as of the date hereof to Payee,
for the purposes of effecting the foregoing application and set off, all of
Maker's rights to receive such deferred compensation after the date hereof,
such that when, as and if such deferred compensation payments shall be due and
payable by Payee to Maker, Maker shall be deemed to have irrevocably assigned
and transferred all rights thereto to Payee, effective as of the date hereof.

         13.     This Note shall be governed by and construed in accordance
with the internal laws of the State of Texas and applicable federal laws of the
United States of America.  This Note has been delivered and accepted and is
payable at Houston, Harris County, Texas.  There are no unwritten or oral
agreements between the Maker and the Payee.  Payee has no commitment to make
any additional loans to or to extend financial accommodations to Maker beyond
the loan evidenced hereby.

         EXECUTED AND EFFECTIVE as of the day and year first above written.

                                    MAKER:
                                    ----- 




                                            /s/ FRANK A. PICI                
                                    -----------------------------------------
                                                Frank A. Pici





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