Chevron

Chevron

Chevron

ConocoPhillips

ConocoPhillips

ConocoPhillips

Sonangol

Sonangol

Sonangol

Hunt Oil Co.

Hunt Oil Co.

Hunt Oil Co.

Cobalt International Energy, Inc.

Cobalt International Energy, Inc.

Cobalt International Energy, Inc.

Conoco, Inc.

Conoco, Inc.

Conoco, Inc.

Tamboran Resources Pty

Tamboran Resources Pty

Tamboran Resources Pty

Energulf Resources

Energulf Resources

Energulf Resources

Otto Energy Limited

Otto Energy Limited

Otto Energy Limited

Antilles Oil & Gas

Antilles Oil & Gas

Antilles Oil & Gas

Franklin Petroleum Limited

Franklin Petroleum Limited

Franklin Petroleum Limited

Interoil Colombia

Interoil Colombia

Interoil Colombia

Methanex Corp.

Methanex Corp.

Methanex Corp.

Burlington Resources

Burlington Resources

Burlington Resources

Perenco Ecuador Limited

Perenco Ecuador Limited

Perenco Ecuador Limited

Pura Vida Energy

Pura Vida Energy

Pura Vida Energy

Ridgewood Energy

Ridgewood Energy

Ridgewood Energy

Falcon Oil & Gas

Falcon Oil & Gas

Falcon Oil & Gas

Allen & Overy

Allen & Overy

Allen & Overy

Pan Orient Energy Corp.

Pan Orient Energy Corp.

Pan Orient Energy Corp.

Quest Petroleum NL

Quest Petroleum NL

Quest Petroleum NL

Three Crowns LLP

Three Crowns LLP

Three Crowns LLP

Seha Corporation

Seha Corporation

Seha Corporation

Freshfields Bruckhaus Deringer

Freshfields Bruckhaus Deringer

Freshfields Bruckhaus Deringer

Norton Rose Fulbright

Norton Rose Fulbright

Norton Rose Fulbright

Instinct Energy Limited

Instinct Energy Limited

Instinct Energy Limited

Nabirm Energy Services

Nabirm Energy Services

Nabirm Energy Services

Apollo Management

Apollo Management

Apollo Management

Larus Energy

Larus Energy

Larus Energy

Newport Energy Limited

Newport Energy Limited

Newport Energy Limited

Sceptre

Sceptre

Sceptre

ODYE Africa

ODYE Africa

ODYE Africa

Cairn Lanka

Cairn Lanka

Cairn Lanka

Jacka Resources

Jacka Resources

Jacka Resources

Northern Gulf

Northern Gulf

Northern Gulf

Valeura Energy

Valeura Energy

Valeura Energy

Nana Regional Corporation

Nana Regional Corporation

Nana Regional Corporation

HKN Inc

HKN Inc

HKN Inc

Moncrief Oil Company

Moncrief Oil Company

Moncrief Oil Company

Alpha Natural Resources

Alpha Natural Resources

Alpha Natural Resources

Magnolia Petroleum

Magnolia Petroleum

Magnolia Petroleum

Northcote Enegy

Northcote Enegy

Northcote Enegy

Cotton Bledsoe Tighe Dawson, PC

Cotton Bledsoe Tighe Dawson, PC

Cotton Bledsoe Tighe Dawson, PC

Glast Phillips & Murray

Glast Phillips & Murray

Glast Phillips & Murray

Hagans Burdine Montgomery Total

Hagans Burdine Montgomery Total

Hagans Burdine Montgomery Total

North American Petroleum PLC

North American Petroleum PLC

North American Petroleum PLC

Viridis Petroleum

Viridis Petroleum

Viridis Petroleum

Anadarko Petroleum

Anadarko Petroleum

Anadarko Petroleum

Gardere Wynne Sewell LLP

Gardere Wynne Sewell LLP

Gardere Wynne Sewell LLP

Mosman Oil & Gas

Mosman Oil & Gas

Mosman Oil & Gas

Noble Energy

Noble Energy

Noble Energy

Alberta Energy Corporation

Alberta Energy Corporation

Alberta Energy Corporation

Amerada Hess

Amerada Hess

Amerada Hess

Apache Corporation

Apache Corporation

Apache Corporation

Bentn Oil & Gas Co.

Bentn Oil & Gas Co.

Bentn Oil & Gas Co.

BHP Petroleum

BHP Petroleum

BHP Petroleum

BP plc

BP plc

BP plc

Canadian Government

Canadian Government

Canadian Government

Crestar Energy

Crestar Energy

Crestar Energy

Dominion Oil & Gas

Dominion Oil & Gas

Dominion Oil & Gas

First International Oil Co.

First International Oil Co.

First International Oil Co.

Frontier Energy NL

Frontier Energy NL

Frontier Energy NL

Globex

Globex

Globex

Khanty Mansiysk Oil Corp

Khanty Mansiysk Oil Corp

Khanty Mansiysk Oil Corp

Landmark Graphics

Landmark Graphics

Landmark Graphics

Marathon Oil

Marathon Oil

Marathon Oil

Netherland Sewell & Associates

Netherland Sewell & Associates

Netherland Sewell & Associates

Nido Petroleum

Nido Petroleum

Nido Petroleum

Norwest Energy

Norwest Energy

Norwest Energy

Ocean Energy, Inc

Ocean Energy, Inc

Ocean Energy, Inc

Petrobank

Petrobank

Petrobank

Reef Exploration, Inc

Reef Exploration, Inc

Reef Exploration, Inc

Singapore Petroleum Co.

Singapore Petroleum Co.

Singapore Petroleum Co.

SK E&P Co.

SK E&P Co.

SK E&P Co.

Sovereign Oil & Gas Co.

Sovereign Oil & Gas Co.

Sovereign Oil & Gas Co.

Tang Energy Group, Ltd.

Tang Energy Group, Ltd.

Tang Energy Group, Ltd.

Tripower Resources

Tripower Resources

Tripower Resources

Triton Energy Corp.

Triton Energy Corp.

Triton Energy Corp.

Trust Company of the West

Trust Company of the West

Trust Company of the West

Union Texas Petroleum

Union Texas Petroleum

Union Texas Petroleum

Warrior Oil Co.

Warrior Oil Co.

Warrior Oil Co.

West Oil NL

West Oil NL

West Oil NL

World GTL Inc.

World GTL Inc.

World GTL Inc.

Xpronet

Xpronet

Xpronet

Acer Energy Limited

Acer Energy Limited

Acer Energy Limited

AEC (Thailand) Ltd

AEC (Thailand) Ltd

AEC (Thailand) Ltd

AES Uruguaiana

AES Uruguaiana

AES Uruguaiana

AFEX International, Inc.

AFEX International, Inc.

AFEX International, Inc.

Africa Fortesa Corporation

Africa Fortesa Corporation

Africa Fortesa Corporation

Aspect Energy Holdings

Aspect Energy Holdings

Aspect Energy Holdings

Altai Resources, Inc.

Altai Resources, Inc.

Altai Resources, Inc.

American Technologies

American Technologies

American Technologies

Andrews & Kurth LLP

Andrews & Kurth LLP

Andrews & Kurth LLP

Anglo-Dutch Petroleum, Inc.

Anglo-Dutch Petroleum, Inc.

Anglo-Dutch Petroleum, Inc.

Anschutz Exploration Corporation

Anschutz Exploration Corporation

Anschutz Exploration Corporation

Antrim Energy, Inc.

Antrim Energy, Inc.

Antrim Energy, Inc.

APA Petroleum Engineering

APA Petroleum Engineering

APA Petroleum Engineering

APEC Partners

APEC Partners

APEC Partners

Arthur Andersen LLP

Arthur Andersen LLP

Arthur Andersen LLP

Aurelian Oil & Gas

Aurelian Oil & Gas

Aurelian Oil & Gas

Avante Petroleum S.A.

Avante Petroleum S.A.

Avante Petroleum S.A.

Bahamas Petroleum Company PLC

Bahamas Petroleum Company PLC

Bahamas Petroleum Company PLC

Beaumont Cornish Limited

Beaumont Cornish Limited

Beaumont Cornish Limited

Bell Murphy & Associates

Bell Murphy & Associates

Bell Murphy & Associates

BG Asia, Inc.

BG Asia, Inc.

BG Asia, Inc.

Bill Barrett Corporation

Bill Barrett Corporation

Bill Barrett Corporation

Blue Energy Ltd.

Blue Energy Ltd.

Blue Energy Ltd.

Bounty Developments Ltd.

Bounty Developments Ltd.

Bounty Developments Ltd.

KBR

KBR

KBR

Caithness Petroleum Limited

Caithness Petroleum Limited

Caithness Petroleum Limited

California Academy of Sciences

California Academy of Sciences

California Academy of Sciences

CAMAC International Corp.

CAMAC International Corp.

CAMAC International Corp.

Carnarvon Petroleum Ltd

Carnarvon Petroleum Ltd

Carnarvon Petroleum Ltd

Central European Petroleum Ltd.

Central European Petroleum Ltd.

Central European Petroleum Ltd.

Century International Oil & Gas

Century International Oil & Gas

Century International Oil & Gas

Cervantes Corporation Limited

Cervantes Corporation Limited

Cervantes Corporation Limited

CLMG Corp

CLMG Corp

CLMG Corp

Cohen & Associates

Cohen & Associates

Cohen & Associates

Consol Energy, Inc.

Consol Energy, Inc.

Consol Energy, Inc.

Consolidated Contractors

Consolidated Contractors

Consolidated Contractors

Cooper Energy Ltd.

Cooper Energy Ltd.

Cooper Energy Ltd.

Crutcher-Tufts Production

Crutcher-Tufts Production

Crutcher-Tufts Production

Cue Energy Resources Limited

Cue Energy Resources Limited

Cue Energy Resources Limited

Davis Petroleum Corporation

Davis Petroleum Corporation

Davis Petroleum Corporation

Debevoise & Pimpton LLC

Debevoise & Pimpton LLC

Debevoise & Pimpton LLC

Delonex Energy

Delonex Energy

Delonex Energy

Devon Energy Corporation

Devon Energy Corporation

Devon Energy Corporation

Duke Energy Corporation

Duke Energy Corporation

Duke Energy Corporation

Egdon Resources

Egdon Resources

Egdon Resources

EIG Global Energy Partners

EIG Global Energy Partners

EIG Global Energy Partners

Endeavour International

Endeavour International

Endeavour International

ERHC Energy, Inc.

ERHC Energy, Inc.

ERHC Energy, Inc.

Esquisto Gas Ltd.

Esquisto Gas Ltd.

Esquisto Gas Ltd.

European Bank for Reconstruction and Development

European Bank for Reconstruction and Development

European Bank for Reconstruction and Development

Fluormin plc

Fluormin plc

Fluormin plc

Foothills Resources

Foothills Resources

Foothills Resources

Frontera Resources Corp

Frontera Resources Corp

Frontera Resources Corp

Global Petroleum Limited

Global Petroleum Limited

Global Petroleum Limited

Greer, Herz & Adams, LLC

Greer, Herz & Adams, LLC

Greer, Herz & Adams, LLC

Grundy & Associates PLL

Grundy & Associates PLL

Grundy & Associates PLL

Gustavson Associates

Gustavson Associates

Gustavson Associates

Harvest Natural Resources

Harvest Natural Resources

Harvest Natural Resources

Hawkley Oil & Gas Limited

Hawkley Oil & Gas Limited

Hawkley Oil & Gas Limited

Horizon Oil Limited

Horizon Oil Limited

Horizon Oil Limited

Horizon Resources, Inc.

Horizon Resources, Inc.

Horizon Resources, Inc.

Hungarian Horizon Energy

Hungarian Horizon Energy

Hungarian Horizon Energy

Husky Oil International, Inc.

Husky Oil International, Inc.

Husky Oil International, Inc.

Hyperdynamics Corporation

Hyperdynamics Corporation

Hyperdynamics Corporation

Independent Resources plc

Independent Resources plc

Independent Resources plc

Innex Energy

Innex Energy

Innex Energy

IPR Group

IPR Group

IPR Group

Iskander Energy Corp.

Iskander Energy Corp.

Iskander Energy Corp.

JGC Corporation

JGC Corporation

JGC Corporation

JKX Oil & Gas

JKX Oil & Gas

JKX Oil & Gas

Kina Oil & Gas Ltd.

Kina Oil & Gas Ltd.

Kina Oil & Gas Ltd.

King & Spalding LLP

King & Spalding LLP

King & Spalding LLP

Kosmos Energy LLC

Kosmos Energy LLC

Kosmos Energy LLC

Kratos Energy Limited

Kratos Energy Limited

Kratos Energy Limited

Kuwait Foreign Petroleum

Kuwait Foreign Petroleum

Kuwait Foreign Petroleum

Lukoil OAO

Lukoil OAO

Lukoil OAO

M. E. Zukerman & Co., Inc.

M. E. Zukerman & Co., Inc.

M. E. Zukerman & Co., Inc.

Maersk Olie og Gas A/S

Maersk Olie og Gas A/S

Maersk Olie og Gas A/S

Edwards Wildman

Edwards Wildman

Edwards Wildman

Maple Energy plc

Maple Energy plc

Maple Energy plc

MENA Hydrocarbons, Inc.

MENA Hydrocarbons, Inc.

MENA Hydrocarbons, Inc.

Mesa Energy Holdings, Inc.

Mesa Energy Holdings, Inc.

Mesa Energy Holdings, Inc.

Milbank, Tweed, Hadley

Milbank, Tweed, Hadley

Milbank, Tweed, Hadley

Miller Energy Resources

Miller Energy Resources

Miller Energy Resources

Ministry (Equatorial Guinea) of Mines & Energy

Ministry (Equatorial Guinea) of Mines & Energy

Ministry (Equatorial Guinea) of Mines & Energy

Ministry (Russia) of Ecology

Ministry (Russia) of Ecology

Ministry (Russia) of Ecology

Ministry (Russia) of Fuel and Energy of the Russia

Ministry (Russia) of Fuel and Energy of the Russia

Ministry (Russia) of Fuel and Energy of the Russia

Minter Ellison Lawyers

Minter Ellison Lawyers

Minter Ellison Lawyers

Mitra Energy Ltd.

Mitra Energy Ltd.

Mitra Energy Ltd.

MND Exploration and Production Ltd.

MND Exploration and Production Ltd.

MND Exploration and Production Ltd.

Monclova Pirineo Gas, SA (MPG)

Monclova Pirineo Gas, SA (MPG)

Monclova Pirineo Gas, SA (MPG)

Mora Oil Ventures Ltd

Mora Oil Ventures Ltd

Mora Oil Ventures Ltd

Morgan Grenfell and Company

Morgan Grenfell and Company

Morgan Grenfell and Company

Moriah Group

Moriah Group

Moriah Group

Mubadala Petroleum (Pearl Energy)

Mubadala Petroleum (Pearl Energy)

Mubadala Petroleum (Pearl Energy)

Natural (Jordan) Resources Authority

Natural (Jordan) Resources Authority

Natural (Jordan) Resources Authority

Natural Gas Partners

Natural Gas Partners

Natural Gas Partners

Neon Energy Limited

Neon Energy Limited

Neon Energy Limited

New Guinea Energy Ltd.

New Guinea Energy Ltd.

New Guinea Energy Ltd.

Nexen, Inc.

Nexen, Inc.

Nexen, Inc.

Ninox Energy Limited (Blacktip Energy)

Ninox Energy Limited (Blacktip Energy)

Ninox Energy Limited (Blacktip Energy)

Ocean East Zeit Petroleum

Ocean East Zeit Petroleum

Ocean East Zeit Petroleum

Odyssey Petroleum Corp.

Odyssey Petroleum Corp.

Odyssey Petroleum Corp.

Opon International LLC

Opon International LLC

Opon International LLC

Origin Energy

Origin Energy

Origin Energy

O'Ryan Oil & Gas

O'Ryan Oil & Gas

O'Ryan Oil & Gas

Osprey Petroleum Company

Osprey Petroleum Company

Osprey Petroleum Company

Pacific Alliance Asia Special Situations Fund L.P.

Pacific Alliance Asia Special Situations Fund L.P.

Pacific Alliance Asia Special Situations Fund L.P.

Paisano Energy, LLC

Paisano Energy, LLC

Paisano Energy, LLC

PEMEX Exploration & Production

PEMEX Exploration & Production

PEMEX Exploration & Production

Petro Canada Resources

Petro Canada Resources

Petro Canada Resources

Po Valley Energy Limited

Po Valley Energy Limited

Po Valley Energy Limited

Poros SAS

Poros SAS

Poros SAS

Porter & Hedges LLP (Ryder Scott)

Porter & Hedges LLP (Ryder Scott)

Porter & Hedges LLP (Ryder Scott)

Porto Energy Corporation

Porto Energy Corporation

Porto Energy Corporation

Quad Energy S.A.

Quad Energy S.A.

Quad Energy S.A.

Reliance Exploration and Production DMCC

Reliance Exploration and Production DMCC

Reliance Exploration and Production DMCC

Rhino Resources, Ltd.

Rhino Resources, Ltd.

Rhino Resources, Ltd.

RISC Pty, Ltd.

RISC Pty, Ltd.

RISC Pty, Ltd.

Sonor Energy

Sonor Energy

Sonor Energy

Impact Energy Partners, LLC

Impact Energy Partners, LLC

Impact Energy Partners, LLC

Bukit Energy

Bukit Energy

Bukit Energy

KrisEnergy

KrisEnergy

KrisEnergy

CamCan Energy Limited

CamCan Energy Limited

CamCan Energy Limited

Pathfinder Energy

Pathfinder Energy

Pathfinder Energy

3D Oil

3D Oil

3D Oil

Govt. of Guinea-Bissau

Govt. of Guinea-Bissau

Govt. of Guinea-Bissau

Genel Energy

Genel Energy

Genel Energy

NuAfrica

NuAfrica

NuAfrica

Bridgeport Energy Limited

Bridgeport Energy Limited

Bridgeport Energy Limited

Risco Energy

Risco Energy

Risco Energy

RMG Limited

RMG Limited

RMG Limited

Roc Oil Company Limited

Roc Oil Company Limited

Roc Oil Company Limited

Rocky Mountain Mineral Law Foundation

Rocky Mountain Mineral Law Foundation

Rocky Mountain Mineral Law Foundation

Russian Federation

Russian Federation

Russian Federation

Sasol Petroleum International

Sasol Petroleum International

Sasol Petroleum International

SBC Warburg

SBC Warburg

SBC Warburg

Sherritt International Total

Sherritt International Total

Sherritt International Total

Soco International plc

Soco International plc

Soco International plc

Sound Oil plc

Sound Oil plc

Sound Oil plc

Southern California Gas Co.

Southern California Gas Co.

Southern California Gas Co.

Staubus/Randall LLP

Staubus/Randall LLP

Staubus/Randall LLP

Stirling Products Ltd

Stirling Products Ltd

Stirling Products Ltd

Stratic Energy Corporation

Stratic Energy Corporation

Stratic Energy Corporation

Sun Resources NL

Sun Resources NL

Sun Resources NL

Tap Oil Ltd.

Tap Oil Ltd.

Tap Oil Ltd.

australian worldwide exploration

australian worldwide exploration

australian worldwide exploration

Terra Insight Corporation

Terra Insight Corporation

Terra Insight Corporation

TG World Energy Corp.

TG World Energy Corp.

TG World Energy Corp.

The Hanover Company

The Hanover Company

The Hanover Company

Frontier Resources International

Frontier Resources International

Frontier Resources International

Westerly

Westerly

Westerly

Tradewinds Oil & Gas

Tradewinds Oil & Gas

Tradewinds Oil & Gas

TransAtlantic Petroleum

TransAtlantic Petroleum

TransAtlantic Petroleum

Triple Five Group

Triple Five Group

Triple Five Group

Tri-Valley Corp.

Tri-Valley Corp.

Tri-Valley Corp.

Twinza Oil Ltd.

Twinza Oil Ltd.

Twinza Oil Ltd.

UBS Warburg, LLC

UBS Warburg, LLC

UBS Warburg, LLC

UHY Hacker Young

UHY Hacker Young

UHY Hacker Young

United Nations

United Nations

United Nations

VAALCO Energy, Inc.

VAALCO Energy, Inc.

VAALCO Energy, Inc.

Vetra Energia - Marketing

Vetra Energia - Marketing

Vetra Energia - Marketing

Walter Oil & Gas International

Walter Oil & Gas International

Walter Oil & Gas International

Wintershall Holding Gmb

Wintershall Holding Gmb

Wintershall Holding Gmb

Worley International

Worley International

Worley International