AEP-WOODFORD
AMERICAN ENERGY PARTNERS
ANADARKO PETROLEUM
ANSCHUTZ EXPLORATION CORPORATION
APACHE CORPORATION
ARENA RESOURCES INC.
ARMOR ENERGY LLC
AVALON EXPLORATION INC
AXIO NATURAL RESOURCES
AXIS ENERGY CORPORATION
BALLARD PETROLEUM
BANNER OIL AND GAS
BARBOUR ENERGY CORPORATION
BBX OPERATING, LLC
BEAR MOUNTAIN RESOURCES LLC
BEASLEY OIL COMPANY
BHP
BINGER OPERATIONS, LLC
BISON EXPLORATION LP
BLUESTONE NATURAL RESOURCES
BNK PETROLEUM (US) INC
BOLD ENERGY
BOPCO
BP AMERICA PRODUCTION COMPANY
BRAVO NATURAL GAS, LLC
BRAVO NATURAL RESOURCES
BRIGHT HORIZON RESOURCES LLC
BURLINGTON RESOURCES OIL & G
BURNETT OIL COMPANY
CALLON PETROLEUM COMPANY
CANYON CREEK RESOURCES LLC
CAPSTONE ENERGY
CAPSTONE NATURAL RESOURCES
CARL E. GUNGOLL EXPLORATION
CASILLAS OPERATING LLC
CASTELLI EXPLORATION, INC.
CDX GAS LLC
CERTEX USA, INC.
CHAPARRAL ENERGY LLC
CHARTER OAK PRODUCTION CO.
CHESAPEAKE
CIMAREX ENEGRY COMPANY
CITATION OIL & GAS CORP.
CITRUS ENERGY CORP.
CLAYTON WILLIAMS ENERGY INC
COG OPERATING LLC
COMANCHE EXPLORATION CO., LLC
CONCHO EXPLORATION INC.
CONOCOPHILLIPS COMPANY
CONTINENTAL RESOURCES INC
CORDILLERA ENERGY
CORTERRA ENERGY OPERATING, LLC
CRAWLEY PETROLEUM
CROW CREEK ENERGY III LLC
CRUSADER ENERGY CORPORATION
DCP MIDSTREAM
DEVON ENERGY CORPORATION
DEWBRE PETROLEUM CORPORATION
DOMINION EXPLORATION
DUNCAN OIL PROPERTIES
EAGLE OIL & GAS COMPANY
EAGLE ROCK MID-CONTINENT
EL TORO RESOURCES
ELK RIVER RESOURCES
ELM RIDGE RESOURCES, INC.
ENCANA OIL & GAS USA
ENCORE ACQUISITION COMPANY
ENCORE OPERATING LP
ENERVEST OPERATING LLC
EOG RESOURCES INC.
EXCALIBUR RESOURCES LLC
FALCON EXPLORATION
FIDELITY EXPLORATION & PRODUCTION
FOREST OIL CORPORATION
FOSSIL CREEK ENERGY
FOUR SEAS EXPLORATION
FREEPORT-MCMORAN OIL & GAS
GASTAR EXPLORATION INC
GHK COMPANY
GLB EXPLORATION, INC.
GREAT PLAINS OPERATING LLC
GREAT WESTERN OPERATING CO LLC
GULFPORT ENERGY
GUNGOLL EXPLORATION
HALCON RESOURCES
HARDING & SHELTON INC.
HESS OHIO DEVELOPMENT
HIGHMOUNT EXPLORATION & PROD
J CLEO THOMPSON OIL & GAS
J.O.C. OPERATING, INC.
JONES ENERGY
KAISER-FRANCIS
KCS RESOURCES, INC.
KERNS PETROLEUM, INC.
KEY PRODUCTION COMPANY, INC.
KILLAM OIL COMPANY LTD
KINDER MORGAN
KINGFISHER RESOURCES, INC.
KIRKPATRICK OIL COMPANY
LARIAT PETROLEUM
LATIGO PETROLEUM, INC.
LE NORMAN OPERATING LLC
LINN ENERGY
LARADO PETROLEUM
MACK ENERGY
MALLARD OIL & GAS
MARATHON OIL COMPANY
MATADOR PRODUCTION COMPANY
MID-CONTINENT ENERGY CORPORATION
MIDSTATES PETROLEUM
MT DORA ENERGY LLC
MUSTANG FUEL CORPORATION
NADEL & GUSSMAN, LLC
NEMAHA OIL & GAS LLC
NEW DOMINION LLC
NEWFIELD MID-CONTINENT
NOBLE ENERGY PRODUCTION INC.
OCCIDENTAL OF ELK HILLS, INC
OXY USA INC
PABLO ENERGY II LLC
PANTHER ENERGY COMPANY, LLC
PARALLEL ENERGY LP
PENN VIRGINIA MC ENERGY, LLC
PENN VIRGINIA OIL & GAS
PEREGRINE PETROLEUM PARTNERS
PERMIAN RESOURCES LLC
PETROHAWK ENERGY CORPORATION
PETRO-HUNT LLC
PETROLEUM DEVELOPMENT CORPORATION
PETROQUEST ENERGY LLC
PIONEER NATURAL RESOURCES
PLAINS EXPLORATION & PRODUCTION
POGO ENERGY, INC.
PREMIER NATURAL RESOURCES INC
PRIDE ENERGY COMPANY
PRIMARY NATURAL RESOURCES
PRODIGY OIL AND GAS
PRODUCTION GATHERING COMPANY
PROTEGE ENERGY LLC
QEP ENERGY COMPANY
QUESTAR EXPLORATION & PRODUCTION
RAM ENERGY, INC.
RAMSEY PROPERTY MGMT, LLC
RANGE RESOURCES CORPORATION
REBELLION ENERGY LLC
RED MOUNTAIN OPERATING LLC
REX ENERGY OPERATING CORPORATION
RICKS EXPLORATION INC.
RILEY EXPLORATION OPERATING
RILEY PERMIAN OPERATING CO LLC
RIMROCK RESOURCE OPERATING LLC
RKI EXPLORATION & PRODUCTION
ROCKCLIFF ENERGY LLC
ROSETTA RESOURCES OPERATING LP
SABINE OIL AND GAS LLC
SAMSON ENERGY
SAMSON RESOURCES
SANDRIDGE ENERGY INC.
SHERIDAN PRODUCTION CO LLC
SLAWSON EXPLORATION COMPANY
SM ENERGY
SOUTHERN INTERNATIONAL
SOUTHWEST ROYALTIES
SPELLER OIL CORPORATION
STEPHENS EXPLORATION INC
STEPHENS PRODUCTION CO
STORM CAT ENERGY
STROUD ENERGY
SUNBELT REPORTING & LITIGATI
SUNDOWN ENERGY LP
TALON OIL & GAS LLC
TAPSTONE ENERGY
TECOLOTE ENERGY
TERRA ENERGY PARTNERS LLC
TOKLAN OIL & GAS CORP.
TOM BROWN INC.
TRAIL RIDGE ENERGY PARTNERS
TRIAD ENERGY
TRILOGY OPERATING
TRINITY OPERATING (USG) LLC
TRIUMPH ENERGY PARTNERS LLC
UNIT PETROLEUM
VANGUARD NATURAL RESOURCES LLC
VINE OIL & GAS
VITRUVIAN EXPLORATION II, LL
WAGON WHEEL OPERATING LLC
WARD PETROLEUM CORPORATION
WARREN AMERICAN OIL COMPANY
WESTERN OIL & GAS
WHITE RIVER ENERGY
WHITE STAR PETROLEUM LLC
WHITING OIL & GAS CORPORATION
WHITING PETROLEUM CORPORATION
WILDHORSE RESOURCES LLC
WILLIFORD ENERGY COMPANY
WINDSOR ENERGY
WPX ENERGY
WYNN-CROSBY ENERGY, INC.
XTO ENERGY
XTO ENERGY INC – PERMIAN
YALE OIL ASSOCIATES, INC.