Comprehensive Study On Geological Conditions Of Coalbed Methane Accumulation In JP Block In Northern Guizhou

The coal seam in the upper Permian series of the JP block in the northern region of Guizhou has a wide distribution and high gas content,and has the potential for CBM development.In this paper,the geological conditions of the CBM accumulation are studied by using the drilling data and its analysis data.In the study area,the CBM accumulation condition is superior:the main coal seam thickness is large,mainly distributed in the upper coal group,the distribution of coal seam M5,M6,M6sec is the most stable.The coal seam structure is better than that of coal structure coal group coal group,the southeast wing is better than the northwest wing.The composition of coal and rock is mainly bright coal,and the coal type is mainly of semi dark type.The average organic component is 79.29%,the ash content of coal bed is medium,which belongs to anthracite coal No.three.In the late stage of pyrolysis.The CBM composition is good,mainly methane,the average gas content of the reservoir 12.17ml/g.The northwest wing in the southeast wing of the methane component and content higher.The gas content of coal seam was positive related with the buried depth of coal seam,the degree of thermal evolution,the content of organic matter and the high level of heat,and it was negative related with the coal ash content,volatile content,the formation dip.The potential of coalbed methane accumulation is mainly controlled by the thickness of coal seam,buried depth,structural stability and thermal evolution:The favorable area is divided into a total of 28.8km2,of which I class area is 13.8km2.The amount of geological resources in the favorable area is 45×108m3,and the abundance of CBM resources is about 1.54×108m3/km2.