Comprehensive Evaluation of Methane Reservoirs Based on TOPSIS

Methane is an unconventional gas which formed and accumulated in coal seams. The effective development and utilization of methane is very important to make full use of energy and improve the energy structure in China. This study focused on the No. 3 seam of the Qinduan block which is influenced by many geological conditions. Eight parameters,which are the content of methane,coal thickness,buried depth of coal seam,temperature,pressure of coal seam,ash content of coal seam,density of coal,and coal vitrinite reflectance have been taken as main indexes to be considered. The methane reservoir has been evaluated comprehensively based on the method of TOPSIS. The results indicate that the method TOPSIS is a simple in calculation and easy in operation,and its weight determination is less affected by subjective factors. The evaluation results are in conformity with reservoir characteristics. Thus it is a new approach for evaluation of gas reservoirs in seams.