Oil & Gas Companies (wholly or primarily government owned).

• Abu Dhabi National Oil Co. (ADNOC)
• China National Offshore Oil Corp. Ltd. (CNOOC)
• China National Petroleum Corp. (CNPC)
• Chinese Petroleum Corp. [Taiwan]
• Dansk Olie og Naturgas AS (DONG) [Denmark]
• Egyptian General Petroleum Corp. (EGPC)
• Empresa Colombiana de Petroleos (Ecopetrol) [Colombia]
• Empresa Nacional del Petroleo (ENAP) [Chile]
• Fortum Oy [Finland]
• Gazprom [Russia]
• Gujarat State Petroleum Corporation Ltd. (GSPC)
• Japan Petroleum Exploration
• Kuwait Petroleum Corp. (KPC)
• Myanma Oil & Gas Enterprise [Myanmar (Burma)]
• National Iranian Oil Co. (NIOC)
• Nigerian National Petroleum Corp.
• Oil & Natural Gas Corp. Ltd. (ONGC) [India]
• Pertamina [Indonesia]
• Petroleo Brasilerio SA (Petrobras)
• Petroleos del Ecuador (PetroEcuador)
• Petroleos del Peru (Petroperu)
• Petroleos de Venezuela SA (PDVSA)
• Petroleos Mexicanos (PEMEX)
• Petroleum Co. of Trinidad and Tobago Ltd. (Petrotrin)
• Petroleum Development Oman LLC
• Petroleum Exploration & Production Authority (PEPA) [Yemen]
• Petronas [Malaysia]
• PTT Exploration & Production Public Co. Ltd. (PTTEP) [Thailand]
• Qatar Petroleum Corp.
• Rompetrol [Romania]
• Saudi Arabian Oil Co. (Saudi Aramco)
• Sonangol [Angola]
• Sonatrach [Algeria]
• State Oil Co. of Suriname Ltd. (Staatsolie)
• Statoil ASA [Norway]
• Turkiye Petrolleri Anonim Ortakligi (TPAO) [Turkey]
• PetroVietnam

Integrated Global (Major) Companies
• Amerada Hess Corp.
• BP plc
• Chevron Corp.
• ConocoPhillips Co.
• ENI SpA
• ExxonMobil Corp.
• Kerr-McGee Corp.
• Marathon Oil Corp.
• Murphy Oil Corp.
• Occidental Petroleum Corp.
• Petro-Canada
• Shell (Royal Dutch/Shell Group)
• Total

Additional Companies - Outside the U.S.
• Baytex Energy Ltd.
• BG Group
• BHP Billiton Ltd.
• Cairn Energy plc
• Canadian 88 Energy Corp.
• Canadian Natural Resources Ltd.
• EnCana Corp.
• Energy Africa
• FX Energy
• Husky Energy Inc.
• Ivanhoe Energy
• Lukoil Oil Co.
• Lundin Petroleum AB
• Mosaic Oil N.L.
• Navigo Energy Inc.
• Nexen Inc.
• New Zealand Oil & Gas Ltd.
• Norsk Hydro ASA
• OMV AG
• Paramount Resources Ltd.
• Penn West Petroleum Ltd.
• PetroKazakhstan
• Premier Oil plc
• Ramco Energy plc
• Repsol YPF
• Santos Ltd.
• Sherritt International Corp.
• Summit Resources
• Talisman Energy Inc.
• Tap Oil Ltd.
• Tullow Oil plc
• Vanco Energy Co.
• Vermilion Resources Ltd.
• Yukos Oil Co.

Additional (Independent) Companies - U.S.
• Abraxas Petroleum Corp.
• Anadarko Petroleum Corp.
• Apache Corp.
• Berry Petroleum Co.
• Burlington Resources Inc.
• Cabot Oil & Gas Corp.
• Callon Petroleum Co.
• Chesapeake Energy Corp.
• Citation Oil & Gas Corp.
• CMS Energy Corp.
• Denbury Resources Inc.
• Devon Energy Corp.
• Eagle Plains Resources Ltd.
• El Paso Corp.
• Energen Corp.
• EOG Resources Inc.
• Equitable Resources
• Forest Oil Corp.
• Houston Exploration Co.
• Koch Industries Inc.
• National Fuels
• Newfield Exploration Co.
• Noble Energy
• Pioneer Natural Resources Co.
• Pogo Producing Co.
• Ruwco Oil & Gas Corp.
• Questar Corp.
• Stone Energy Corp.
• Swift Energy Co.
• Unocal Corp.
• Vintage Petroleum Inc.
• Williams Companies Inc.
• XTO Energy