- Abu Dhabi Oil
- Akita Natural Gas Pipeline
- AKITA Prefecture
- AGC
- Avery Laurence
- Bets
- Cosmo Energy Exploration & Production
- DJK (Daiichi Jitsugyo Co.)
- Daruma Tekkou
- GSC (Geophysical Surveying Co.)
- Geosys
- Godo Shigen Co.
- Halliburton Overseas Ltd. Japan
- Idemitsu Kosan
- IHS Markit
- Inpex Corporation
- Inpex Southwest Caspian Sea
- Ise Chemicals Corporation
- Itochu Oil Exploration
- Itochu Techno-Solutions Corporation
- JDC (Japan Drilling Co.)
- Japan Natural Gas Association
- JODCO (Japan Oil Development Co.)
- JOE (Japan Oil Engineering Co.)
- JOGMEC (Japan Oil Gas and Metals National Corporation)
- Japan Petoroleum Development Association
- JAPEX (Japan Petroleum Exploration)
- Japan Space Systems
- JPO (Japex Offshore)
- JFE Steel Corporation
- JGC Corporation
- JGI
- JX Nippon Exploration & Development
- JX Nippon Oil & Gas Exploration
- Kanto Natural Gas Development
- Kyokutou Boeki Kaisha
- MQJ (Mantle Quest Japan)
- Mitsubishi Corporation Exploration
- Mitsubishi Gas Chemical
- MOECO (Mitsui Oil Exploration Co.)
- MODEC. Inc.
- Nihon Tennen Gas Co.
- Nippoh Chemicals
- Nippon Steel Engineering
- Nippon Steel
- Valqua Ltd.
- Ocean Engineering Research, Inc.
- OOC (Offshore Operation Co.)
- Palynosurvey
- Summit Exploration and Production Limited.
- PGS Japan
- SODECO (Sakhalin Oil and Gas Development Co.)
- Schlumberger K. K.
- SKE (SK Engineering)
- Teikoku Oil (D.R. Congo)
- TDC (Teiseki Drilling Co.)
- Telnite
- Inpex Engineering (Japan)
- United Petroleum Development
- Cosmos Shoji
- INPEX SAHUL, LTD.
- Emerson Automation Solutions, E&P Software
- Shoshin Corporation
- Fukada Salvage & Marine Works
