Interlayer contradiction problem in coalbed methane development： a case study in Liulin area

The implement of separate layer fracturing and multiple layers drainage for vertical CBM wells is an effective method to reduce costs of exploration and development, and to increase productivity. Based on theories of conventional reservoirs, the concept, characteristics and influence factors of interlayer contradiction in CBM development are firstly proposed and summarized. Features of typical production curves in Liulin area are analyzed, and characteristics and reasons of interlayer contradiction and development suggestions are given. The result shows that the interlayer contradiction is serious when coal seams(No.8+9) in Taiyuan Formation and seams (No.3+4+5) in Shanxi Formation are drained. Property characteristics of coal seams and hydrogeological conditions of roof and floor are two factors for interlayer contradiction in the area, of which the later is the main factor.