非在来型原油・天然ガス開発への挑戦

抄録

The author believes there is no other way to solve short and medium term energy problems than to place the fossil fuel energy, which currently accounts for more than 80% of primary energy, at the center of energy. To supply as much oil and gas as possible to Japan, Japanese government and petroleum related companies are trying to obtain concessions/equities for the development of petroleum including unconventional oil and gas all over the world. Recently, unconventional oil and gas attract attention as next generation energy, because of their vast amount of resources. A part of the unconventional oil and gas has been already produced on a commercial scale, while the development of some of them is still in the stage of research. This paper first gives an outline of unconventional oil and gas, followed by the introduction to the development/production methods and problems/challenges.

Two main methods of cold production and thermal method are being applied as an in-situ recovery of heavy-oil/extra-heavy-oil/bitumen. For the thermal methods, advanced production methods including the combination of steam and solvent injection as well as the in-situ upgrading are investigated. In the shale gas/oil exploitation, the area of high productivity, which is called a ‘sweet spot,’ is confined to small parts of a formation. Toward the identification of this sweet spot, there is a variety of research work conducted. The research work for the development of methane hydrate has started recently. In-situ development methods and enhanced gas recovery by nitrogen/CO₂ injection are being investigated for the development of oil shale and coalbed methane reservoirs, respectively.

Although there are many problems for the exploitation of unconventional oil and gas, including those of uncertain reserves and development methods, high cost and environmental issues, studies and challenges to overcome these problems are steadily progressing.