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                                                                   EXHIBIT 10(y)



                                 PROMISSORY NOTE


$10,000,000.00                                           Oklahoma City, Oklahoma
                                                               December 20, 2000


                  FOR VALUE RECEIVED, the undersigned, SEVEN SEAS PETROLEUM
INC., a Yukon Territory, Canada corporation (the "Borrower"), promises to pay to
the order of STILLWATER NATIONAL BANK AND TRUST COMPANY, N.A. (the payee, its
successors and assigns are hereinafter called the "Lender"), at 6305 Waterford
Boulevard, Suite 205, Oklahoma City, Oklahoma 73118, or at such other place as
may be designated in writing by the Lender, the principal sum of TEN MILLION
DOLLARS ($10,000,000.00), or so much thereof as is disbursed hereunder, together
with interest thereon at the rates hereinafter stated:

                  Prior to Default, advances under this Note will bear interest
                  from the date of advance at the per annum rate equal to the
                  Reference Rate plus 75/100 percent (.75%). All interest will
                  be computed for the actual number of days elapsed at a per
                  diem charge based on a year consisting of three hundred sixty
                  (360) days.

                  Provided that no event of Default has occurred or is
                  continuing under any of the Loan Documents, there will be no
                  required principal payments on this Note until December 31,
                  2001. Commencing on January 31, 2001, and on the last day of
                  each successive month thereafter until this Note is paid in
                  full, the Borrower will pay to the Bank all accrued unpaid
                  interest on this Note. The entire unpaid principal balance of
                  this Note plus all accrued and unpaid interest thereon will be
                  due and payable on December 31, 2001.

                  Unless otherwise defined herein, all terms defined or
referenced in that certain Loan Agreement of even date herewith between the
Borrower and the Lender (the "Loan Agreement") will have the same meanings
herein as therein.

                  This Note is executed and delivered in connection with the
Loan Agreement. Advances and payments hereunder may, at the option of the
Lender, be recorded on this Note or on the books and records of the Lender and
will be prima facie evidence of said advances, payments and unpaid balance of
this Note. It is specifically agreed that the aggregate of advances made during
the term of this Note may exceed the face amount hereof, but the unpaid
principal balance outstanding at any time will not exceed such face amount. All
payments will first be applied to the payment of accrued interest and the
balance will be applied in reduction of the principal balance hereof provided
that no payment will be applied to this Note until received by the Lender in
collected funds. All


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advances made or to be made under this Note will be made subject to the terms
and conditions stated in the Loan Agreement.

                  The Borrower will have the right at any time to prepay this
Note in whole or in part, without premium or penalty, but with interest accrued
to the date of prepayment.

                  The Borrower agrees that if, and as often as, this Note is
placed in the hands of an attorney for collection or to defend or enforce any of
the Lender's rights hereunder or under any instrument securing payment of this
Note, the Borrower will pay the Lender's reasonable attorneys' fees, all court
costs and all other expenses incurred by the Lender in connection therewith.

                  Any sum not paid when due, by acceleration or otherwise, will
bear interest at the per annum rate equal to the greater of (a) fifteen percent
(15%), or (b) the Reference Rate plus five percent (5%), and such interest which
has accrued will be paid at the time of and as a condition precedent to curing
any Default hereunder. During the existence of any such Default, the Lender may
apply any payments received on any amount due hereunder or under the terms of
any instrument now or hereafter evidencing or securing this indebtedness as the
Lender determines from time to time.

                  This Note is issued by the Borrower and accepted by the Lender
pursuant to a lending transaction negotiated, consummated and to be performed in
Oklahoma City, Oklahoma. Payment of this Note is secured by and subject to the
terms and conditions of the Loan Documents. This Note is to be construed
according to the internal laws of the State of Oklahoma. All actions with
respect to this Note, the Loan Documents or any other instrument securing
payment of this Note may be instituted in the courts of the State of Oklahoma
sitting in Oklahoma County, Oklahoma, or the United States District Court
sitting in Oklahoma City, Oklahoma, as the Lender may elect, and by execution
and delivery of this Note, the Borrower irrevocably and unconditionally submits
to the jurisdiction (both subject matter and personal) of each such court and
irrevocably and unconditionally waives: (a) any objection the Borrower might
now or hereafter have to the venue in any such court; and (b) any claim that any
action or proceeding brought in any such court has been brought in an
inconvenient forum.

                  On the occurrence of an event of Default or the breach of any
provision of this Note, any of the Loan Documents or any other instrument
securing payment of this Note, at the option of the Lender, the entire
indebtedness evidenced by this Note will become immediately due, payable and
collectible then or thereafter as the Lender might elect, regardless of the date
of maturity hereof. Failure by the Lender to exercise such option will not
constitute a waiver of the right to exercise the same in the event of any
subsequent Default.

                  The makers, endorsers, sureties, guarantors and all other
persons who may become liable for all or any part of this obligation severally
waive presentment for payment, protest and notice of nonpayment. Said parties
consent to any extension of time (whether one or more) of payment hereof,
release of all or any part of the security for the payment hereof or release of
any party liable for the payment of this obligation. Any such extension or
release may be made without notice to any such party and without discharging
such party's liability hereunder.


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                  IN WITNESS WHEREOF, the Borrower has executed this instrument
effective the date first above written.


                                   SEVEN SEAS PETROLEUM INC., a Yukon
                                   Territory, Canada corporation


                                   By /s/ LARRY A. RAY
                                     --------------------------------
                                     Larry A. Ray, President

                                   (the "Borrower")




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