Evaluation of deep high-rank coal seam gas content and favorable area division based on GIS: A case study of the South Yanchuan block in Ordos Basin

The South Yanchuan block is the deepest developed high-rank coalbed methane (CBM) field in China, geological conditions this are complex and main controlling factors of CBM content various. Thus, a decision-making model potential deep resource based on geographical information system (GIS) weighted linear combination (WLC) established, influence analyzed, favorable areas divided. Results show that buried depth, coal rank hydrodynamic condition seam dominant control gas scale, while has weak correlation with maceral composition, thickness effective overlying strata. study area divided into five units according to natural breaks method, i.e., extramely favourable area, relatively normally unfavourable which account for 14.23%, 22.23%, 24.77%, 25.08% 13.70% respectively. located northwestern block, considered be key exploration development area. will deepen understanding south Block, practical significance recovery