Features of upper Paleozoic coalbed methane reservoir in eastern Ordos Basin

It is indicated that,as far as the upper Paleozoic coal bed meathane reservoir is considered,the gas pole and plant tissue holes are the dominant storing spaces in eastern Ordos Basin.The large pores and micro-pores are amount to 80%~90% of the pore volume.The poor effective porosity of coal makes the cracks as the principal migration tunnel.Meanwhile,the orientation of main crack is controlled by stress field,and accords with the principal stress.The cracks are obviously zonally developed from the north to the south.Based on the analysis above stated,it is therefore concluded that,Wupu~Liulin and Xiangning-Hancheng areas should be taken as target areas for coalbed methane exploration.