CLIENT LIST

TCA revenues for engineering services and software sales have been derived from the following companies:

UNITED STATES
          Aminoil USA                               Huntington Beach, CA
          ARCO Oil & Gas, CO.                       Dallas, TX
          British Petroleum                         Anchorage, Alaska
          Bass Enterprises                          Fort Worth, Texas
          Belco Petroleum Corporation               Houston, Texas
          Belridge Oil Company                      McKittrick, CA
          B.W.O.C.                                  Bryan, TX

          Cabot Energy                              Houston, TX
          Cities Service Company                    Tulsa, OK
          Continental Oil Co. (Conoco)              Ponca City, OK
          Cornell Oil Company                       Dallas, TX
          Cornell Heavy Oil Process                 Dallas, TX
          Double Barrel Oil Company                 Bakersfield, CA

          Exxon Company USA                         Midland, TX
          Exxon Production Research Co.             Houston, TX
          Gary Energy Company                       Denver, CO
          Getty Oil Company                         Houston, TX
          Grace Petroleum Corporation               Oklahoma City, OK
          Hunt Oil Company                          Dallas, TX

          McFarland Energy Company                  Sante Fe Springs, CA
          Mitchell Energy & Development             Houston, TX
          Pacific Enterprises                       Dallas, TX
          Shell Western E&P Inc.                    Houston, TX
          Southland Royalty Corporation             Fort Worth, TX
          Standard Alaska (British Petroleum)       Anchorage, AK
          Superior Oil Company                      Denver, CO
          Tenneco Oil Company                       Houston, TX
          Texaco USA                                Houston, TX
          Transco Exploration Company               Houston, TX
          Union Oil Company of California           Brea, CA
CANADA
          Alberta Energy Company, Ltd.              Calgary
          Alberta Oil Sands Technology
            and Research Authority                  Calgary
          Dome Petroleum, Ltd.                      Calgary
          Esso Resources Canada, Ltd.               Calgary
          Gulf Resources Canada, Ltd.               Calgary
          Mobil Oil Canada, Ltd.                    Calgary
          PanCanadian                               Calgary
          Shell Resources Canada, Ltd.              Calgary
          Vikor Resources, Ltd.                     Calgary
AUSTRALIA
          Santos Ltd.                               North Adelaide
          Moonie Oil Company, Ltd.                  Brisbane
EOROPE
          Maersk                                    Copenhagen
          Wintershall AG                            Kassel, Germany
          Mobil AG                                  Celle, Germany
          Preussag                                  Hannover, Germany
SOUTH AMERICA
          ENAP (Chile)                              Punta Arenas
          INTEVEP (Venezuela)                       Los Teques
          Corpoven (Venezuela)                      Puerto La Cruz
          Lagoven   (Venezuela)                     Maturin, Los Teques
          Maraven (Venezuela)                       Caracas
          San Jorge (Argentina)                     Buenos Aires
          Trinidad Tesoro Petroleum Co. Ltd.        Santa Flora

TCA develops numerical reservoir simulators for use in the design of primary depletion, waterflooding and enhanced oil recovery projects. As of this time, we have developed both non-volatile and volatile-oil thermal simulators, a compositional-based miscible flood simulator, a foam flood simulator, a black- oil simulator, and a scale-up model for predicting field project behavior from simple pattern-element simulations. In addition, we have developed various utility programs to aid in data preparation.

Although these programs were primarily developed as engineering tools for use by TCA personnel, a number of oil producing companies have either purchased or leased them. The following companies have purchased (perpetually licensed), leased or rented (royalty usage) one or more of TCA's reservoir simulators:

ALBERTA OIL SANDS TECHNOLOGY (AOSTRA)
AMINOIL USA
ARCO OIL & GAS COMPANY (ARCO)
BASS ENTERPRISES
BP EXPLORATION INC.
CITIES SERVICE COMPANY (OXY)
CONTINENTAL OIL COMPANY (CONOCO)
EXXON COMPANY USA
GARY ENERGY COMPANY
HUDSON'S BAY OIL & GAS COMPANY, LTD.
HUSKY OIL
MOBIL RESEARCH AND DEVELOPMENT COMPANY
PETROLEOS DE VENEZUELA, S.A.
SANTOS LTD. (AUSTRALIA)
SHELL CANADA RESOURCES, LTD.
UNION OIL COMPANY OF CALIFORNIA