Comparison and revelation of coalbed methane resources distribution characteristics and development status between China and America

In order to make a relatively objective conclusion on the CBM outlook in China,based on the deep comparison of CBM geological conditions and resources distribution characteristics in China and America,the study,which is on CBM development status of two countries,was carried out,and therefore,the strategic orientation of coalbed methane development in China was put forword.The results show that the CBM geological conditions in America is better than those in China as a whole.The reservoir permeability of American CBM is generally greater than 5×10-3μm2，and producing layers are mostly normal pressure or over pressure.In contrast，the reservoir permeability in China is usually less than 1×10-3μm2，and producing layers are mostly low pressure.The technically recoverable resources of CBM in the United States are mainly concentrated in foreland basins,and resources in Cenozoic are almost equal to those in Mesozoic or in Paleozoic.While CBM resources are roughly equally split between medium and low coal rank,the high coal rank resources are few.In comparison，the technically recoverable resources of CBM in China are mostly concentrated in Craton Basins,and resources in Mesozoic and those in Paleozoic are nearly half and half,while those in Cenozoic are few.Besides,resources from low,medium and high coal rank are roughly equivalent in China.Comprehensive analysis holds that the CBM is an important supplement to the natural gas production in China,and the annual output of CBM in the future is expected to reach 10～20 billion cubic meters.