コールベッドメタン増進回収の生産性予測

抄録

Enhanced coalbed methane recovery (ECBMR) has been paid attention as a new technology of both methane production and carbon dioxide sequestration. This paper describes sensitivity analysis of reservoir characteristics and development plan using ECBMR simulator (ECOMERS-UT) developed by the authors. The results provide basic data for economic evaluation of ECBMR and its optimum development planning. The validity of the simulation results was confirmed by the comparison with the study performed in GEO-SEQ project. The influence of permeability of coal seam, pore model considering matrix swelling, adsorptivity of carbon dioxide and gas composition of injection gas was evaluated. Coal seam of low permeability showed high enhancement effect and sequestration potential although such coal seam showed low production rate. In case of lowering of injectivity resulting from low permeability or large matrix swelling, ECBMR was not effective. High adsorptivity of carbon dioxide led to large sequestration and small enhancement effect. Also, nitrogen rich injection gas led to small sequestration, large enhancement effect and low methane concentration of produced gas.