ABA ENERGY CORPORATION
ADVANCED OILFIELD SERVICES INC
AERA ENERGY
ALTA ROCK ENERGY
ANADARKO PETROLEUM
ANSCHUTZ EXPLORATION COMPANY
ATLAS ENERGY RESOURCES
ATLAS OILFIELD CONSTRUCTION LLC
BAYTEX ENERGY USA LTD
BERRY PETROLEUM
BP AMERICA PRODUCTION COMPANY
BREITBURN ENERGY
BURTCH CONSTRUCTION
CAL ASH
CALPINE OPERATING SERVICES COMPANY, INC.
CARRIZO OIL & GAS
CENTRAL RESOURCES
CHESAPEAKE ENERGY
CHEVRON U.S.A. INC (CA)
CHIEF OIL & GAS LLC
CIMAREX ENERGY CO
CNX
DEWALT
ENCANA OIL & GAS – WYOMING
EOG RESOURCES
EVERTSON COMPANIES
EXXON COLORADO
EXXONMOBIL (CA)
FOOTHILL ENERGY LLC
GEO ECOLOGY
GREEN HORIZON
GREKA INTEGRATED, INC.
GRENADIER ENERGY PARTNERS
J W OPERATING COMPANY
J.A. JONES COMPANY
J.P. OIL COMPANY
LA PALOMA GENERATING COMPANY
LEGACY ENERGY, INC.
MARATHON OIL – CO
MARATHON WY
MATRIX OIL CORPORATION
MATRIX OIL CORPORATION (WHITTIER, CA)
MERIT ENERGY
MIDWEST MANUFACTURING
NATIONS PETROLEUM CALIFORNIA
NEWFIELD ROCKY MOUNTAIN
NOBLE ENERGY
OCCIDENTAL OF ELK HILLS
ORMATT NEVADA INC
OXY USA, INC. (L.A. BASIN)
PANOCHE ENERGY CENTER
PANTHER ENERGY COMPANY, LLC
PATHFINDER SYSTEMS
PCL INDUSTRIAL SERVICES, INC.
PDC MOUNTAINEER LLC
PENNSYLVANIA GENERAL ENERGY
PETRO-CANADA RESOURCES
PIXLEY-CREEK
PLAINS PETROLEUM
PXP
QEP
RAM POWER, INC.
RANGE RESOURCES
RENAISSANCE PETROLEUM
REX ENERGY
ROSETTA RESOURCES INC.
SALINAS ENERGY
SAMSON INVESTMENT COMPANY
SAMSON RESOURCES
SAN JOAQUIN FACILITIES
SANTA MARIA PACIFIC, LLC
SEMPRA ENERGY
SENECA RESOURCE
SIERRA RESOURCES
SIGNAL HILL PETROLEUM
SOLIMAR ENERGY
SOUTHERN CALIFORNIA GAS COMPANY
SOUTHWESTERN ENERGY
STOCKDALE OIL & GAS
STONE ENERGY
STRAIN ORCHARDS
SUGARLAND FARMS LLC
SUNDOWN ENERGY
T.E.G. OIL & GAS USA
TARTAN ENERGY USA CORP
TEMBLOR PETROLEUM
TERMO CO
TERRALOG TECHNOLOGIES USA, INC.
TEXACO
THUMS L.B. CO
TOM BROWN INC
TPI PETROLEUM INC
TRI-VALLEY OIL AND GAS CO.
TRIO PETROLEUM
TRUE OIL ENTERPRISES, LLC
TRUE OIL LLC
TUTOR SALIBA CONSTRUCTION
ULTRA PETROLEUM
UTE INDIAN TRIBE ENERGY & MINERALS DEPT.
VAQUERO ENERGY INC.
VENOCO, INC.
VINTAGE PRODUCTION CA, LLC
WARREN RESOURCES
WASTE MANAGEMENT
WHITING OIL & GAS CORPORATION
WOLVERINE GAS & OIL
XTO – PA
XTO ENERGY INC
YATES PETROLEUM
ZODIAC