ADDAX Petroleum (Switzerland)
Anadarko (United Kingdom)
BEB Erdgas und Erdöl GmbH (Germany)
BGP (China)
BGR Federal Institute for Geosciences & Natural
Resources (Germany)
BP (United Kingdom) & (USA)
British Gas (United Kingdom)
Cairn Energy PLC (United Kingdom)
Cabre Maroc (United Kingdom)
Centrica Energy (United Kingdom)
Chevron Texaco (United Kingdom) & (USA)
COWI A/S (Denmark)
Dansk Naturgas A/S (Denmark)
DEUSA GmbH (Germany)
Deilmann Erdöl Erdgas GmbH (Germany)
DMT (Germany)
DONG A/S (Denmark)
EEG GmbH (Germany)
El Paso (USA)
EnCana (Canada)

Exxon Mobil Production Germany (Germany)
Faroe Petroleum (United Kingdom)
Gedco (Canada)
Geonafta ( Lithuania)
Geowindow Co. Ltd. (Japan)
GNPOC (Sudan)
Heritage Oil Ltd. (United Kingdom)
Hess Ltd. (United Kingdom)
KBB GmbH (Germany)
Linde Gas (Germany)
Maersk Olie og Gas (Denmark)
Max Petroleum (Kazakhstan)
Medusa Oil & Gas SP. z o.o (Poland)
Mobil Erdgas-Erdöl GmbH (Germany)
NIOC (Iran)
North Sea Oil Company (USA)
Nafta a.s. Gbely (Slovakia)
NAM B.V. (The Netherlands)
Occidental Oil and Gas Corporation(USA)
Oil India Ltd. (India)

OMV AG (Austria)
OMV Albania ( Albania)
PDO (Petroleum Development Oman)
PDOC Petrodar Operating Co. (Sudan)
Pemex (Mexico)
Perenco (United Kingdom)
PetroCanada (United Kingdom)
Petrochina Xinjiang (China)
Petrochina Sichuan (China)
Petronas ( Malaysia )
Pioneer Natural Resources (USA)
POL (Pakistan OilFields Limited)
Premier Oil (United Kingdom)
Premier Kufpec Pakistan B.V. (Pakistan)
Preussag Energie GmbH (Germany)
Qatar Petroleum
RAG Rohöl-Aufsuchungs AG (Austria)
Ramboll (Denmark)
Repsol YPF (Spain)
Ruhrgas AG (Germany)
RWE DEA AG (Germany)

RWE DEA Netherlands B. V. (Netherlands)
RWE DEA Polska SP. z o.o (Poland)
Samek International (Kazakhstan)
Sasoil West Africa Limited (USA)
Sipetrol (United Kingdom)
Sinopec Shengli (China)
SPP a.s. Bratislava (Slovakia)
Statoil ASA (Norway)
Sterling Energy PLC (UK)
Sydkraft AB (Sweden)
TEIKOKU (Japan)
Tullow Oil (Ireland)
VEBA Oel GmbH (Germany)
VITO, Flemish institute for
technological research (Belgium)
VNG Verbundnetz Gas AG (Germany)
Wintershall AG (Germany)
Wintershall Libya (Libya)
Wintershall Noordzee B. V. (Netherlands)
Wintershall Norge (Norway)
Woodside Petroleum Ltd. (Australia)
Zhibek Resources PLC (Kyrgyzstan)