Exhibit 4.2
October 16, 1998




Mr. Roland Frautschi
Chief Financial Officer
Goodrich Petroleum Corporation
333 Texas Street, Suite 1350
Shreveport, LA  71101-2300

Re:      Credit  Agreement  by and  between  Patrick  Petroleum  Corporation  of
         Michigan ("Borrower") and Compass Bank-Houston ("Lender"), dated August
         16,  1995 (as  subsequently  amended,  restated  or  supplemented,  the
         "Credit Agreement").

Dear Roland:

Pursuant to Section  2.7(b) of the Credit  Agreement,  Lender has  increased the
Borrowing Base applicable to the Borrower's  Revolving Line of Credit to a level
of  $31,000,000,  effective  upon the  preparation  and execution of appropriate
documentation.  Subject  to the terms and  conditions  of the  Credit  Agreement
(including  Sections  2.7(b)(c)(d)),  this Borrowing Base shall remain in effect
until the next  Borrowing  Base review date,  which is currently  scheduled  for
January 1, 1999.

In addition, effective upon your acknowledgement of this letter, Section 6.11 of
the Credit Agreement shall be amended to read as follows:

         "6.11 Consolidated Tangible Net Worth. Permit Consolidated Tangible Net
         Worth at any  time to be less  than  $6,000,000  plus,  for all  fiscal
         quarters  ending  on or  after  September  30,  1998,  50% of  positive
         Consolidated Net Income and 100% of all cash equity proceeds."

Please note that all  capitalized  terms used but not defined  herein shall have
the meanings attributed thereto in the Credit Agreement.

Please  acknowledge your agreement and acceptance of the foregoing by initialing
page one of this document and executing  page two in the space  provided  below.
Kindly  return the signed  original to my  attention  at the  address  indicated
below, along with a check in the amount of $12,5000, which represents a facility
fee pursuant to Section 2.10 of the Credit  Agreement.  In the interim,  I would
appreciate  it if you  would  forward  a copy  of the  executed  document  to my
attention via facsimile at (713) 968-8292.

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Sincerely,
COMPASS BANK - HOUSTON


By:       /s/  Allison Hammer            
- -----------------------------            
          Allison Hammer
          Vice President


AGREED TO AND ACCEPTED AS OF THIS 16TH DAY OF OCTOBER, 1998:

GOODRICH PETROLEUM COMPANY OF LOUISIANA



By:       /s/  Roland L. Frautschi       
- ----------------------------------       
          Roland L. Frautschi
          Chief Financial Officer



GOODRICH PETROLEUM CORPORATION


By:       /s/ Roland L. Frautschi        
- ---------------------------------        
          Roland L. Frautschi
          Chief Financial Officer


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