Current status and geological conditions for the applicability of CBM drilling technologies in China: A review

Current status, challenges, and policy suggestions for coalbed methane industry development in China: A review

“…Compared to the estimated results in 2006, the total CBM resource is reduced by 7 tcm; however, the technically recoverable resource is increased by 1.6 tcm, indicating improved resource evaluation accuracy and reliability. As shown in Figure , the CBM is mainly distributed in four gas regions in China (Northeast, Northwest, North, and South China), and CBM resources are relatively concentrated and mainly associated with large basins (basin groups) in five stratigraphic strata (Carboniferous‐Permian and Jurassic in North China, Permian in South China, Jurassic in Northwest China, and Jurassic‐Cretaceous in Northeast China) . Among them, the CBM resources in North China account for 46.6% of the total resources, and the resources in Qinshui and Ordos Basins account for 37.8%.…”

“…Moreover, China is projected to provide a quarter of the rise in global gas demand, and the projected import is estimated to be 280 bcm in 2040; this will make China a linchpin of the global gas trade, only behind the European Union . Therefore, the supplementation of unconventional gas, such as CBM, is especially important because CBM is an important type of natural gas and has a large reserve in China …”

Current status and key factors for coalbed methane development with multibranched horizontal wells in the southern Qinshui basin of China

“…59 For hydrofractured horizontal wells, the well trajectory should be as perpendicular as possible to the direction of the maximum principal stress, and the tensile stress region is preferred. Therefore, the well trajectory should be orthogonal to the face cleat direction, meaning that the horizontal well should be drilled perpendicular to the high-permeability direction, which is beneficial for the horizontal well to maximally penetrate the face cleats and communicate with high-permeability face cleats.…”

Characteristics of in situ stress and its influence on coalbed methane development: A case study in the eastern part of the southern Junggar Basin, NW China

“…4 Stress field data from coal-bearing basins at home and abroad indicate that in situ stress regime often shows an obvious belting phenomenon in the vertical direction. [11][12][13][14] By controlling the opening or closing of the coal reservoir pore-fracture system, the current in situ stress regime has obvious control effects on K, P o , G, artificial fracture expansion, and the process of drainage and pressure lowering. [11][12][13][14] By controlling the opening or closing of the coal reservoir pore-fracture system, the current in situ stress regime has obvious control effects on K, P o , G, artificial fracture expansion, and the process of drainage and pressure lowering.…”