Abstract:

Comprehensive evaluation of coalbed methane zone is a complex system，which is controlled by multi-factors and is difficult to estimate. This paper proposes an index system of evaluation based on correlated factors involved in coalbed methane zone and a comprehensive evaluation model that combines the advantages of the AHP and a grey clustering method to guarantee the accuracy and objectivity of weight coefficients. First, the weight of every index is confirmed using the AHP, then a comprehensive evaluation is done by a grey clustering method. In this way, it improves and generalizes some known evaluation methods. An example to illustrate the application of the theoretical results is given. The results show that the method is applicable and realistic with regard to the comprehensive evaluation.In 121 coalbed methane zones in China, Qinshui Basin and the east margin of Ordos Basin are most advantaged zones and the south margin of Ordos Basin,Ningwu, Anyang-Hebi, Songzao are comparatively advantaged zones.

Key words: coalbed methane, evaluation, index system, analytic hierarchy process(AHP), grey clustering method