Coalbed methane (CBM) extraction is of great significance to the sustainable development of China’s energy strategy. Based on the analysis of interaction between CBM and coal
and transport process of CBM
the critical measures for enhancing CBM extraction are including increasing pressure gradient and promoting gas desorption. CO2 injection works on increasing yeild of CBM extraction from both two sides. Compared with natural depressurization recovery
the calculation formulas of amount increasement and ratio increasement are deduced. Defining the concept of comparative CBM recovery increasing ratio
the effect of increasing yield is evaluated for CBM extraction by CO2 injection.