1 EXHIBIT 99.1 JOINT FILING AGREEMENT The parties hereto agree that pursuant to Rule 13d-1(f)(1)(iii) of Regulation 13D promulgated by the Securities and Exchange Commission pursuant to the Securities Exchange Act of 1934, as amended, the Schedule 13D...

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                                                                   EXHIBIT 99.1


                           JOINT FILING AGREEMENT

      The parties hereto agree that pursuant to Rule 13d-1(f)(1)(iii) of
Regulation 13D promulgated by the Securities and Exchange Commission pursuant
to the Securities Exchange Act of 1934, as amended, the Schedule 13D of which
this Agreement is made an exhibit is filed on behalf of it in the capacity set
forth below.


Date:  November 6, 1996                 NATURAL GAS PARTNERS, L.P.


                                        By:  G.F.W. Energy, L.P.,
                                             its Sole General Partner


                                        
                                        By:  /s/ X. Xxxxxx Xxxxxxx            
                                             -------------------------------- 
                                             X. Xxxxxx Xxxxxxx,               
                                             General Partner                  
                                                                              


Date:  November 6, 1996                 G.F.W. ENERGY, L.P.


                                        By:  /s/ X. Xxxxxx Xxxxxxx           
                                             ---------------------------------
                                             X. Xxxxxx Xxxxxxx,
                                             General Partner