Multi-scale prediction of coal seam fracture development in MG block, eastern margin of Ordos Basin

Finding out the development characteristics of coal seam fractures is of great significance for coalbed methane exploitation and safe production of underground coal mines. Logging and seismic are effective means of geophysical identification of coal seam fractures. Electrical imaging, resistivity, density, sonic differential time, natural gamma, neutron porosity and array acoustic logs are used to describe the small scale fracture morphology of No.8 and No.9 coal seams of MG block in the eastern margin of Ordos Basin. The middle-scale fracture of No.8 and No.9 coal seams was predicted by prestack Azimuth AVO inversion in OVT domain. And the large-scale fracture distribution of No.8 and No.9 coal seams in the study area was described in detail based on the poststack seismic intrinsic coherence, coherent enhancement attribute and fracture simulation attribute. According to the post-stack seismic data and pre-stack inversion analysis, the fractures of No.8 and No.9 coal seams in the study area developed two groups of NW and NNE trending fractures. This work has established a multi-scale geophysical prediction method of coal seam fractures from micro to macro, which will provide important geological basis for coalbed methane exploration selection and coal seam safety mining in the study area.