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                                                                   EXHIBIT 10.15


                              AMENDED AND RESTATED
                              CONVERTIBLE DEBENTURE

DATE: DECEMBER 31, 2001                                            US $2,159,746

1.       ISSUANCE

         1.1 FOR VALUE RECEIVED Madison Oil Company (the "CORPORATION")
acknowledges itself indebted and hereby unconditionally promises to pay to or to
the order of PHD Partners LP (the "HOLDER") by 5:00 p.m. (Dallas time) on March
31, 2006 (the "DATE OF MATURITY") at the address of the Holder specified below
or as otherwise directed by the Holder, the principal amount of $2,159,746 in
lawful money of the United States of America (the "PRINCIPAL") together with
interest thereon as hereinafter provided. The Corporation shall have the right
to prepay any principal amount owing pursuant to this Debenture, without notice
or bonus, on thirty (30) days written notice to the Holder. Toreador Resources
Corporation ("TOREADOR"), the sole shareholder of the Corporation, acknowledges
and agrees that its common stock may be used to pay the Interest, as defined
below, and any part of the principal amount due upon the Holder's desire to
convert the whole or any part of this Debenture, subject to the terms specified
below.

         1.2 Interest shall accrue on the principal amount outstanding hereunder
from and after the date hereof both before and after maturity, default and/or
judgment at the rate of 10% per annum and shall be paid quarterly in arrears
(hereinafter referred to as the "INTEREST"). Interest shall be paid, at the
Corporation's option in (i) cash, or (ii) common shares of Toreador (the
"TOREADOR SHARES"), priced at the Conversion Price (as defined herein).

2.       CONVERSION

         2.1      CONVERSION PRIVILEGE AND CONVERSION PRICE

                  (1) Upon compliance with and subject to the terms and
         conditions of this Article 2, the Holder shall have the right, at its
         option, at any time up to, but not after the close of business on the
         last business day prior to the Date of Maturity (such time and date
         being referred to as the "TIME OF EXPIRATION"), to convert the whole or
         any part of the principal amount of this Debenture into Toreador Shares
         at the Conversion Price.

                  (2) This right of conversion extends only to the maximum
         number of whole Toreador Shares into which the aggregate principal
         amount of the Debenture or Debentures surrendered for conversion at any
         time by the Holder or Holders thereof may be converted in accordance
         with the foregoing provisions of this SECTION 2.1. Fractional interests
         in Toreador Shares will be adjusted for in the manner provided in
         SECTION 2.4.

         2.2      CONVERSION PROCEDURE

                  (1) A Holder desiring to convert this Debenture in whole or in
         part into Toreador Shares shall surrender this Debenture to the
         Corporation together with the conversion notice in the form set forth
         in the Debenture or in a form otherwise satisfactory to the Corporation
         and Toreador, duly executed by the Holder or the Holder's executors or
         administrators or other legal representatives or its or their attorney
         duly appointed by an instrument in writing in form and executed in a
         manner satisfactory to the Corporation and Toreador, exercising the
         right to convert this Debenture in accordance with the provisions of
         this ARTICLE 2 stating the principal amount which the Holder elects to
         convert. Thereupon the Holder and/or, subject to payment of all
         applicable stamp or security transfer taxes or other governmental
         charges and compliance with all reasonable requirements of Toreador,
         its nominee(s) or


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         assignee(s), shall be entitled to be entered in the books of Toreador
         as at the Date of Conversion as hereinafter defined (or such other date
         as is specified in SUBSECTION 2.2(2)) as the Holder of the number of
         Toreador Shares into which this Debenture has been converted in
         accordance with the provisions of this ARTICLE 2 and, as soon as
         practicable thereafter (and, in any event, no later than seven (7)
         business days thereafter), Toreador shall make available for pickup
         where the Debenture is surrendered, a certificate or certificates for
         such Toreador Shares and, if applicable, the Corporation shall make
         available for pickup, a check for any amount payable pursuant to
         SECTION 2.4, unless indicated otherwise on the conversion notice.

                  (2) For the purposes of this ARTICLE 2, a Debenture shall be
         deemed to be surrendered for conversion on the date (the "DATE OF
         CONVERSION") on which it is so surrendered in accordance with the
         provisions of this ARTICLE 2 and, in the case of a Debenture so
         surrendered by post or other means of transmission, on the date on
         which it is received by the Corporation provided that if a Debenture is
         surrendered for conversion on a day on which the register of Toreador
         Shares is closed, the person or persons entitled to receive the
         Toreador Shares shall become the holder or holders of record of such as
         at the date which such register is next reopened.

                  (3) Any part of a Debenture maybe converted as provided in
         this ARTICLE 2 and all references to conversion of Debentures shall be
         deemed to include conversion of such parts.

                  (4) The Holder of any Debenture of which part only is
         converted in accordance with SECTION 2.1 shall, upon the exercise of
         the right of conversion, surrender that Debenture to the Corporation,
         and the Corporation shall cancel the same and shall, without charge,
         forthwith certify and deliver to the Holder a new Debenture or
         Debentures in an aggregate principal amount equal to the unconverted
         part of the principal amount of the Debenture so surrendered.

                  (5) There shall be a payment or adjustment by the Corporation
         on account of any Interest accrued or accruing on this Debenture from
         the date of issue up to but not including the Date of Conversion.
         Toreador Shares issued upon such conversion shall rank only in respect
         of dividends declared in favor of stockholders of record on or after
         the Date of Conversion or such later date as such Holder becomes the
         holder of record of such common shares pursuant to SUBSECTION 2.2(2),
         from which applicable date they shall for all purposes be and be deemed
         to be issued and outstanding as fully paid and non-assessable Toreador
         Shares. No adjustment will be made for dividends on the Toreador Shares
         which are issued upon conversion of Debentures surrendered for
         conversion.

                  (6) Surrender to the Corporation by a Holder of a Debenture
         upon the exercise of the rights of conversion provided in this ARTICLE
         2 shall be a good discharge to the Corporation subject to delivery of a
         share certificate for the appropriate number of Toreador Shares issued
         upon such conversion, and, if applicable, a check for any amount
         payable under SECTION 2.4, by the Corporation, and the Corporation and
         Toreador shall not be bound to inquire into the title of such holder,
         save as ordered by a court of competent jurisdiction or as required by
         statute. Neither the Corporation nor Toreador nor any registrar shall
         be bound to see to the execution of any trust affecting the ownership
         of any Debenture nor be charged with notice of any equity that may be
         subsisting in respect thereof, unless the Corporation, Toreador or such
         registrar has actual notice thereof.


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2.3      CONVERSION AT OPTION OF CORPORATION

         In the event that all trades of Toreador Shares on the Nasdaq National
Market System (or on any other exchange on which such shares are then listed)
are at a price greater than US $6.75 for a period of 60 consecutive days (the
"QUALIFICATION PERIOD"), Corporation may by written notice (the "PUT NOTICE")
delivered to the Holder not later than 30 days after the end of any
Qualification Period, require that the Holder convert the whole of the Principal
(but not less than the whole) into Toreador Shares at the Conversion Price.

2.4      NO REQUIREMENT TO ISSUE FRACTIONAL SHARES

         Toreador shall not be required to issue fractional Toreador Shares upon
the conversion of Debentures pursuant to this ARTICLE 2. If more than one
Debenture is surrendered for conversion at one time by the same Holder, the
number of whole Toreador Shares issuable upon conversion thereof will be
computed on the basis of the aggregate principal amount of this Debenture to be
converted. If any fractional interest in the Toreador Shares would, except for
the provisions of this SECTION 2.4, be deliverable upon the conversion of any
principal amount of Debentures, the Corporation shall, in lieu of Toreador
delivering any certificate of such fractional interest, satisfy such fractional
interest by paying to the Holder of such surrendered Debenture an amount in
lawful money of the United States of America (computed to the nearest cent)
equal to the balance of the principal amount of the Debenture tendered for
conversion.

2.5      CANCELLATION OF CONVERTED DEBENTURES

         All Debentures converted in whole or in part under the provisions of
this ARTICLE 2 shall forthwith be delivered to and cancelled by the Corporation
and, subject to the provisions of SUBSECTION 2.2(4), no Debenture shall be
issued in substitution therefor.

2.6      TOREADOR TO RESERVE SHARES

         Toreador covenants that it shall at all times reserve and keep
available out of its authorized common shares, solely for the purpose of
issuance upon conversion of this Debenture as provided in this ARTICLE 2, and
conditionally issue to Holders who may exercise their conversion rights
hereunder such number of Toreador Shares as would be issuable upon the
conversion of this Debenture. Toreador covenants that all Toreador Shares which
shall be so issuable shall, on surrender and conversion of Debentures in
accordance with the terms hereof, be duly and validly issued as fully paid and
non-assessable, free from pre-emptive or similar rights on the part of the
holders of any common shares or any other person and free from all liens and
charges with respect to the issue thereof.

2.7      TAXES AND CHARGES ON CONVERSION

         Toreador will from time to time promptly pay any and all taxes and
charges which may be imposed by the laws of the United States or any state
thereof (except income tax or security transfer, tax, if any) which are payable
by Toreador with respect to the issuance and/or delivery to the Holder of this
Debenture, of Toreador Shares pursuant to the terms of this Debenture.

2.8      APPLICABLE SECURITIES LEGISLATION

         The Corporation and Toreador shall not, directly or indirectly, do any
act or thing or, to the extent that it is able, permit any act or thing to be
done, which would remove or deny any registration or prospectus exemption
available under any applicable securities legislation with respect to the
issuance of Toreador Shares upon the exercise of the conversion rights contained
in this Debenture.


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2.9      ADJUSTMENT OF CONVERSION PRICE

         The Conversion Price (as hereinafter defined) in effect at any date
shall be subject to adjustment from time to time as follows:

                  (a) If and whenever at any time prior to the Time of
         Expiration, Toreador shall (i) subdivide or redivide the outstanding
         Toreador Shares into a greater number of shares, (ii) reduce, combine
         or consolidate the outstanding Toreador Shares into a smaller number of
         shares, or (iii) issue Toreador Shares to the holders of all or
         substantially all of the outstanding Toreador Shares by way of a stock
         dividend (other than the issue of common shares to holders of common
         shares, pursuant to their exercise of options to receive dividends in
         the form of common shares in lieu of dividends paid in the ordinary
         course on the common shares), the Conversion Price in effect on the
         effective date of such subdivision, redivision, reduction, combination,
         consolidation or on the record date of such issue of Toreador Shares by
         way of a stock dividend, as the case may be, shall be adjusted to that
         amount determined by multiplying the Conversion Price in effect
         immediately prior to such date by a fraction, of which the numerator
         shall be the number of Toreador Shares outstanding on such date before
         giving effect to such subdivision, redivision, reduction, combination,
         consolidation or stock dividend and of which the denominator shall be
         the number of Toreador Shares outstanding after giving effect thereto.
         Such adjustment shall be made successively whenever any event referred
         to in this SUBSECTION 2.9(a) shall occur. Any such issuance of Toreador
         Shares by way of a stock dividend shall be deemed to have been made on
         the record date for the stock dividend for the purpose of calculating
         the number of outstanding Toreador Shares under SUBSECTIONS (b) and (c)
         of this SECTION 2.9.

                  (b) If and whenever at any time prior to the Time of
         Expiration Toreador shall fix a record date for the issuance of rights,
         options or warrants to all or substantially all the holders of Toreador
         Shares entitling them, for a period expiring not more than forty-five
         (45) days after such record date, to subscribe for or purchase Toreador
         Shares (or securities convertible into Toreador Shares) at a price per
         share (or having a conversion or exchange price per share) less than
         the Conversion Price (as hereinafter defined) per Toreador Share on
         such record date, then, the Conversion Price shall be adjusted
         immediately after such record date so that it shall equal the price
         determined by multiplying the Conversion Price in effect on such record
         date by a fraction, of which the numerator shall be the total number of
         Toreador Shares outstanding on such record date plus a number of
         Toreador Shares equal to the number arrived at by dividing the
         aggregate price of the total number of additional Toreador Shares
         offered for subscription or purchase (or the aggregate conversion or
         exchange price of the convertible securities so offered) by such
         Current Market Price per Toreador Share, and of which the denominator
         shall be the total number of Toreador Shares outstanding on such record
         date plus the total number of additional Toreador Shares offered for
         subscription or purchase (or into which convertible securities so
         offered are convertible); any Toreador Shares owned by or held for the
         account of Toreador shall be deemed not to be outstanding for the
         purpose of any such computation. Such adjustment shall be made
         successively whenever such a record date is fixed. To the extent that
         any such rights or warrants are not so issued or any such rights or
         warrants are not exercised prior to the expiration thereof, the
         Conversion Price shall be readjusted to the Conversion Price which
         would then be in effect if such record date had not been fixed or to
         the Conversion Price which would then be in effect based upon the
         number of Toreador Shares (or securities convertible into Toreador
         Shares) actually issued upon the exercise of such rights or warrants,
         as the case may be.

                  (c) If and whenever at any time prior to the Time of
         Expiration Toreador shall fix a record date for the making of a
         distribution to all or substantially all the holders of its


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         outstanding common shares of (i) shares of any class other than common
         shares and other than shares distributed to holders of common shares
         pursuant to their exercise of options to receive dividends in the form
         of such shares in lieu of dividends paid in the ordinary course on the
         common shares or (ii) rights, options or warrants (excluding those
         referred to in this SUBSECTION 2.9(b)) or (iii) evidences of
         indebtedness or (iv) assets (excluding dividends paid in the ordinary
         course), then in each such case, subject to the approval of the Nasdaq
         National Market System and/or any other exchange on which the Toreador
         Shares are then listed, the Conversion Price shall be adjusted
         immediately after such record date so that it shall equal the price
         determined by multiplying the Conversion Price in effect on such record
         date by a fraction, of which the numerator shall be the total number of
         Toreador Shares outstanding on such record date multiplied by the
         Current Market Price per Toreador Share on such record date, less the
         fair market value (as determined by the board of directors, which
         determination shall be conclusive) of all such shares or rights,
         options or warrants or evidences of indebtedness or assets so
         distributed, and of which the denominator shall be the total number of
         Toreador Shares outstanding on such record date multiplied by such
         Current Market Price per Toreador Share; any Toreador Shares owned by
         or held for the account of Toreador shall be deemed not to be
         outstanding for the purpose of any such computation. Such adjustment
         shall be made successively whenever such a record date is fixed. To the
         extent that such distribution is not so made, the Conversion Price
         shall be readjusted to the Conversion Price which would then be in
         effect if such record date had not been fixed or to the Conversion
         Price which would then be in effect based upon such shares or rights,
         options or warrants or evidences of indebtedness or assets actually
         distributed as the case may be. In clause (iv) of this SUBSECTION
         2.9(c), the term "dividends paid in the ordinary course" shall include
         the value of any securities or other property or assets distributed in
         lieu of cash dividends paid in the ordinary course at the option of
         shareholders.

                  (d) In the case of any reclassification or change (other than
         a change resulting only from consolidation or subdivision) of the
         Toreador Shares or in case of any amalgamation, consolidation or merger
         of Toreador with or into any other corporation, or in the case of any
         sale of all or substantially all of the assets of Toreador, as or
         substantially as, an entirety to any other corporation, the Conversion
         Price shall be adjusted so that each Debenture shall, after such
         reclassification, change, amalgamation, consolidation, merger or sale,
         be convertible into the number of shares or the number, kind or amount
         of other securities or property of Toreador, or such continuing,
         successor or purchaser corporation, as the case may be, which the
         Holder thereof would have been entitled to receive as a result of such
         reclassification, change, amalgamation, consolidation, merger or sale
         if on the effective date thereof he had been the holder of the number
         of common shares into which the Debenture was convertible prior to the
         effective date of such reclassification, change, amalgamation,
         consolidation, merger or sale. No such reclassification, change,
         amalgamation, consolidation, merger or sale shall be carried into
         effect unless, in the opinion of the directors of Toreador, all
         necessary steps shall have been taken to ensure that the Holders shall
         thereafter be entitled to receive such number of shares or other
         securities or property of Toreador, or such continuing, successor or
         purchasing corporation, as the case may be, subject to adjustment
         thereafter in accordance with provisions similar, as nearly as may be,
         to those contained in this SECTION 2.9.

                  (e) In any case in which this SECTION 2.9 shall require that
         an adjustment shall become effective immediately after a record date
         for an event referred to herein, Toreador may defer, until the
         occurrence of such event, issuing to the Holder of any Debenture
         converted after such record date and before the occurrence of such
         event, the additional Toreador Shares issuable upon such conversion by
         reason of the adjustment required by such event; provided, however,
         that Toreador shall deliver to such Holder an appropriate instrument
         evidencing such Holder's right to receive such additional Toreador
         Shares upon


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         the occurrence of the event requiring such adjustment and the right to
         receive any distributions made on such additional Toreador Shares
         declared in favor of holders of record of Toreador Shares on and after
         the Date of Conversion or such later date as such Holder would, but for
         the provision of this SUBSECTION 2.9(e), have become the holder of
         record of such additional Toreador Shares pursuant to SUBSECTION
         2.2(2).

                  (f) The adjustments provided for in this SECTION 2.9 are
         cumulative and shall apply to successive subdivisions, redivisions,
         reductions, combinations, consolidations, distributions, issues or
         other events contemplated herein resulting in any adjustment under the
         provisions of this SECTION 2.9, provided that, notwithstanding any
         other provision of this SECTION 2.9, no adjustment of the Conversion
         Price shall be required unless such adjustment would require an
         increase or decrease of at least 1% in the Conversion Price then in
         effect; provided, however, that any adjustments which by reason of this
         SUBSECTION 2.9(f) are not required to be made shall be carried forward
         and taken into account in any subsequent adjustment.

                  (g) In the event of any question arising with respect to the
         adjustments provided in this SECTION 2.9 such question shall be
         conclusively determined by a firm of certified public accountants
         appointed by Toreador (who may be Toreador's auditors); such
         accountants shall have access to all necessary records of Toreador and
         such determination shall be binding upon Toreador and the Holder.

                  (h) In the case Toreador shall take any action affecting the
         Toreador Shares other than action described in this SECTION 2.9 which
         in the opinion of the directors of Toreador would materially affect the
         rights of the Holder, the Conversion Price shall be adjusted in such
         manner and at such time, by action of the directors, as the directors
         in their sole discretion may determine to be equitable in the
         circumstances which action shall be subject to the prior approval of
         the Nasdaq National Market System (and/or any other exchange on which
         such shares are then listed). Failure of the directors to make such an
         adjustment shall be conclusive evidence that the directors have
         determined that it is equitable in the circumstances to make no
         adjustment.

                  (i) "CONVERSION PRICE" means US $6.75 per Toreador Share or
         such other dollar amount for which each Toreador Share may be issued
         from time to time upon the conversion of Debentures in accordance with
         the provisions of this ARTICLE 2.

         2.10     NOTICE AS TO ADJUSTMENT

         Toreador shall, except in respect of any subdivision, redivision,
reduction, combination, consolidation or reclassification of the Toreador
Shares, forthwith give notice to the Holders specifying the event requiring such
adjustment or readjustment and the results thereof, including the resulting
Conversion Price; provided that, if Toreador has given notice under SECTION 2.9
covering all the relevant facts in respect of such event, no such notice need be
given under this SECTION 2.10.

3.       COVENANTS

         3.1      CONSENT REQUIRED

         The written consent of the Holder shall be required prior to the taking
of any action or entering into of any agreement which would restrict or
interfere with the Corporation's ability to make Interest or Principal payments
pursuant to this Debenture.


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4.       TRANSFERABILITY

         4.1      NEGOTIABLE INSTRUMENT

         This Debenture shall be treated as a negotiable instrument and may be
sold, transferred, assigned, pledged, encumbered or otherwise dealt with or
disposed of, absolutely or by way of security, without the prior written consent
of the Corporation or Toreador.

5.       GENERAL

         5.1      NOTICE

                  Any notice to be given hereunder shall be effective personally
         or sent by regular mail, postage prepaid, or if sent by facsimile as
         follows:

                  if to the Corporation:     Madison Oil Company
                                             9400 North Central Expressway,
                                               Suite 1209
                                             Dallas, Texas 75231 U.S.A.

                                             Fax No. 214.373.7892

                  If to Toreador:            Toreador Resources Corporation
                                             4809 Cole Avenue, Suite 108
                                             Dallas, Texas 75205 U.S.A.

                                             Fax No. 214.559.3945

                  if to the Holder:          PHD Partners LP
                                             33 Plymouth Road
                                             Summit, New Jersey

                                             Fax No. 908.273.8348
                                             and     214.369.6020

         5.2      PRESS RELEASE

                  Except to the extent required by law or with the prior written
         consent of the Holder, such consent not to be unreasonably withheld,
         the Corporation and Toreador shall not make any public announcement
         regarding this Debenture.

         5.3      RECEIPT OF TRUE COPY

                  The Corporation and Toreador acknowledge having received a
         true copy of this Debenture.

         5.4      SUCCESSORS AND ASSIGNS

                  This Debenture and all its provisions shall enure to the
         benefit of and be binding upon the Holder and shall be binding on the
         Corporation and Toreador, their successors and assigns. The term
         "successor" shall include, without limiting its meaning, any company
         resulting from the amalgamation of the Corporation or Toreador with any
         other company.


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         5.5      JURISDICTION

                  This Debenture shall be construed in accordance with the laws
         of the State of Texas and the parties hereto irrevocably attorn to the
         jurisdiction of the courts of the State of Texas.


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<PAGE>

         IN WITNESS WHEREOF the Corporation, Toreador and the Holder have caused
this Debenture to be signed by their proper officers duly authorized as of the
date first shown above.


                                    MADISON OIL COMPANY


                                    By: /s/ RICHARD D. PRESTON
                                        ----------------------------------------
                                    Name:  Richard D. Preston
                                    Title: Chief Financial Officer


                                    TOREADOR RESOURCES CORPORATION


                                    By: /s/ G. THOMAS GRAVES III
                                        ----------------------------------------
                                    Name:  G. Thomas Graves III
                                    Title: President and Chief Financial Officer


                                    PHD PARTNERS LP

                                    By:  Madison Co. Inc.,
                                         Its General Partner

                                    By: /s/ DAVID M. BREWER
                                        ----------------------------------------
                                    Name:  David M. Brewer
                                    Title: President


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