Field Tests on CO2 Injection into Coal Seams and ECBM in
Kotaro Ohga1, Masaji Fujioka2, Shinji Yamaguchi3, Miyao Nako4
1. Hokkaido University, Japan 2. Japan Coal Energy Center, JAPAN
3. Akita University, JAPAN 4. General Enviromental Technos Co.,LTD.,
The project for the development of technology of CO2 sequestration in the coal seams , which is called JCOP, has been commenced since JFY2002 with full subsidy from Ministry of Economy, Trade and Industry. Yuubari area of Ishikari coal field in Hokkaido was selected as the most suitable pilot test field, because the coal seams of this area are gassy and permeable. This project is divided into three phases. The fist phase is for fundamental field test from 2002 to 2006. The second phase is for full scale test and the last phase is for commercial base. Injection well (IW-1)was drilled in the end of 2003, production well(PW-1) was drilled in the summer of 2004. The distance in the coal seam between the vertical injection well (IW-1) and the deviated production well (PW-1) was about 66m. .We injected CO2 into the coal seam in 2004 and 2005. Total weight of injected CO2 was about 150t.
From the results of the injection tests, following things were cleared; the gas production rate increased few days after starting CO2 injection and the gas production rate reached maximum rate which was three times as much as the initial production rate. And then at a few days after stopping injection, it decreased. CO2 injection has been continued in this year, therefore we will introduce the results of this year.