Criteria for selected areas evaluation of low rank CBM based on multi-layered fuzzy mathematics：A case study of Turpan-Hami Basin

Abstract：Thick coal seams, which exist in many basins of the low rank CBM in China, have good reservoir property and abundant CBM resources. However, there is no proper model for evaluation of low rank CBM at present. The methods and theories of the optimal selection of favorable areas of low rank CBM are still in the process of improvement. Taking Turpan-Hami Basin which occupies 50% of the total resources of low rank CBM in China as an example, the authors applied the multi-layered fuzzy mathematic model to quantitative sequencing of 19 key factors, such as resource factors, coal reservoir factors, and preserve factors. According to the special geological conditions of Turpan-Hami Basin and the method of assignment, weighting, summation and quantitative sequencing, the evaluation standards of the regional selection of CBM were set up for exploring evaluation standards of low rank CBM and main factors influencing methane occurrence in China. The results obtained by the authors show that the next key areas of exploration and development are Hami depression, Sha'erhu superficial depression and Da'nanhu superficial depression.