Aminex
ARCO
Beicip-Franlab
BHP
Borders & Southern
Petroleum
Buried Hill Services (UK) Ltd
Chevron
ChevronTexaco
Clements Exploration
Inc.
Corelab
East African Oil
Company Ltd.
ECL
Exile Resources Ltd.
ExxonMobil
Fina
First Exchange Inc.
Fortesa Inc.
Fugro Geoscience Division
Gaffney Cline
Geolab
Geotrex Systems
Gravity Diamonds Pty Ltd.
Kuwait Oil Company
Lagoven
Maurel et Prom
Merlin
Mitsubishi
Mobil
Nexen
Norsk Hydro
Occidental
PanAfrican Energy
PanOcean Energy
Perenco
Phillips
Regal Petroleum
ROC Oil Company
Rocksource
RPS Energy
Soco
Statoil
Surestream
Synergy
Texaco
TimeTrax
Triton
Vaalco Energy Inc.
Zeta Petroleum