Coalbed methane reservoir-forming pattern of low rank coal in Erlian basin: with Huolinhe basin as an example

To establish coal bed methane reservoir-forming pattern of low coal rank faulted basin, this paper studied geological conditions and CBM geological features in Huolinhe basin to get CBM enrichment regularity. It was concluded that in Huolinhe basin coal seam thickness is 80 meters and coal bed gas content is between 1.6~5.62 m³/t. Coal bed methane weathering line is about 450~500 meters deep. Distribution of coal is controlled by contemporaneous structure and sedimentary environments. Inner basin, the small depressions and uplifts decided the location of coal seam development and affected the burial depth of coal seams.The overall uplifting of the basement determined the location of gas weathered zone. In the middle of Wengnenghua syncline and south-west syncline, coal seam is favorable to coal bed methane reservoir, because of big thickness of coal seam, appropriate buried depth of coal seams, roof and floor lithology of mudstone and being little affected by later tectonic.