CRIS -Creative Research Institution- Hokkaido University


Title of the Research Project:

Research Division of the Japan Petroleum Exploration Co., Ltd. (JAPEX) Earth Energy Frontier


Established at:

Endowed Research Division, Research Department, Creative Research Institution Sousei, Hokkaido University


Project Duration:

1 April 2009_31 March 2014


Funded by:

Japan Petroleum Exploration Co., Ltd. (JAPEX)


Main objectives:

  1. Elucidate the behavior of coalbed methane and shale gas in connection with deep subsurface exploration.
  2. Better understand the Cenozoic petroleum system.


Research activities:

The petroleum and natural gas resources currently in use by mankind were produced mostly from hydrocarbons that were generated thermally in the Earth’s deep subsurface, subsequently migrated into porous strata, and accumulated to form subsurface oil and gas reservoirs. Petroleum and natural gas that underwent this process of generation, migration, and accumulation comprise the conventional petroleum resources.Intensive prospecting of petroleum-bearing resources around the globe has led to the discovery of numerous conventional oil and gas resources. As these resources are limited in quantity, the rate of their discovery has been decreasing with time.

Regions characterized by ongoing crustal movements (e.g., active vulcanism and intense seismic activity) are generally poor in oil and gas traps and geological structures suitable for the accumulation of oil and gas resources. Moreover, such areas are vulnerable to the destruction of already existing traps. Bearing this in mind, this research division is pursuing the potential for new types of natural oil and gas resources that occur in active regions such as Japan.

Thanks to a vast dataset accumulated thus far and also additional data acquired by the 3D Geophysical Survey Vessel ”Shigen” released by the Japanese Agency of Natural Resources & Energy in 2008, further details on the subsurface structure in and around Japan are becoming known. These data suggest that the deep subsurface of the region from Sakhalin to Central Hokkaido and across the region off Sanriku (see Figure) is characterized by widely distributed strata of Eocene age (ca. 56-34 Myr ago). The peculiar feature to be noted here is the large-scale presence of coalbeds in these strata. The Yufutsu Oil/Gas Field (situated 3900?4800 m below ground level), the largest of its kind in Japan, discovered by JAPEX and in production since 1996, is located in this area (see Figure), and the oil and gas produced there originated from the Eocene coalbeds.

The wide occurrence of coalbeds at great depths is a peculiar yet common feature of the regions adjacent to Japan and eastern Asia that exhibit significant crustal motion. Deep burial of the coalbeds in these regions and subsequent heating resulting in maturation are believed to have generated an enormous quantity of petroleum and natural gas.

Sedimentary basins (dark green) containing regions with thick deposits of coalbeds
Sedimentary basins (dark green) containing regions with thick deposits of coalbeds