Study on coal seam physical characteristics and influence on stimulation: A case study of coal seams in zhengzhuang block

Coalbed Methane (CBM) is an unconventional form of natural gas which self-generated and self-stored in coal seams. In order to realize the effective exploitation CBM Zhengzhuang block, microstructure, wettability, permeability, rock mechanics in-situ stress were studied this research. It found that high rank anthracite characterized by vitrinite content low inorganic mineral content, abundant CBM. More than 96% minerals are clays dominated kaolinite illite. Various types pores developed on coal. The wettability differs from surface water, active foam fracturing fluid; contact angles with water fluid decrease increase burial depth. Gradients fracture pressure closure No.3 seam higher No.15 seam. elastic modulus lower sandstone. construction curve hydraulic shows that, when flow rate sand quantity similar, prepad pumping seam, but propagated drainage effect large pore volume, shallow depth obvious better comprehensive understanding physical properties engineering practice block provide certain guiding significance Qinshui Basin.