ARCO 
Atmos Energy
Barrett Resources
BellWether Exploration
BP
Burlington Resources, Inc.
ChevronTexaco
Cliff’s Drilling Company
Dow Chemical
Duke Energy
Dynegy
Enogex
Equilon
Equistar
Equiva Services LLC
Global Marine
Global Octanes
Gulf Interstate Engineering Co.
Hilcorp Energy
International Alliance Group
Kinder-Morgan Inc.
Kraton Polymers
LaBarge Inc.
Lyondell Petrochemical
Marathon Oil Company
Sakhalin Energy
Marathon/Ashland
National Oilwell

Motiva International Enterprises
Network International
Nuevo Energy
Ocean Energy, Inc.
Paragon Engineering
Parker Drilling Company
Petrozuata
Plains Resources
Reliant Energy
Resolution Performance Products
Schlumberger
Shell Oil
SK Global America
Sonat Exploration
Sterling Chemicals
Tejas Gas
Texaco
The Westlake Group
Torch Energy Advisors
Tesoro Petroleum
Total Fina Elf
Union Carbide
Unocal
Valero Energy
Weatherford
Western Gas Resources
Williams Company
Wilson Supply

A.E.C. Express
Air Liquide
Allwaste Inc.
AutoNation
Baylor College of Medicine
Bettis Corporation
Brinker
BT Office Products International
Chemical Lime
Comsys
Crown Castle International
Deloitte Touche
eBreviate
Health Link
Hopestar Orthopedic Group
HydroChem Industrial
I.R.I. International