Evaluation of coalbed methane drainage effect for multi-target seams in Jincheng region

The study of the multi-target seams drainage effect on coalbed methane wells has great value, including coal safe mining, underground gas control, determination of development technical indicators, single well production, rational division of development layer, efficient development of coalbed methane, and development of medium and long-term coalbed methane development planning. Taking Chengzhuang mine of Jincheng as an example, the sampling data of the extraction effect in the middle and late stages of development are compared with the original gas content of the adjacent wells to evaluate the extraction effect, and the main control factors affecting the drainage effect are analyzed by combining the geological data and the on-site drainage data. According to the comprehensive analysis, it has been found that the No.15 coal seam has gas content lower than that of the No.3 and No.9 coal seams through surface coalbed methane extraction after several years. The analysis showed that the main influence factors for the rapid reduction of gas content of No.15 coal seam in Chengzhuang mining area include the coal gas content, permeability, liquid supply capacity, reservoir pressure in coal seam and producing measures, which provide a scientific basis for the prediction of remaining reserves.