Comprehensive evaluation study on favorable area of coalbed methane reservoir in southern Shizhuang Block

In order to overcome the problems such as lack of evaluation parameters of the favorable area of coalbed methane and difficulty in determining the weight of the main control parameters,the main control factors of the coalbed methane favorable area are evaluated by the grey correlation method,and the weights are quantitatively evaluated by the judgment matrix to provide objective analysis for the rapid evaluation of the favorable area of coalbed methane.On this basis,making full use of the dynamic and static parameters such as drilling data,fracturing data and production data of the parametric wells and production wells to finely evaluate the characteristics of the main coal seams in the south block of Shizhuang Area,and a multi-level mathematics evaluation model was constructed to predict the distribution of favorable reservoirs.The block was divided into three levels of development geological units.The results show that the block coal reservoirs are dominated by Class I and Class Ⅱ reservoirs.The Class Ⅰ reservoirs are mainly located in the central part,distributed along the NNE direction,and the Class Ⅲ reservoirs are distributed in the north and south.The remaining areas are Class Ⅱ reservoirs.In addition,according to the production dynamics,the results of the evaluation are in good agreement with the gas production; 23 third-level development geological units are divided,and C-I1,C-I2,C-I3 and C-I4 are considered as favorable areas for gas extraction yields.