CBM Well Production Influence Factors And Measures To Increase Production

CBM(Coal Bed Methane), of which methane is the main component, exists in thecoal seam, and it is mainly absorbed in the surface of the coal matrix while the rest ispresent in the coal pore or dissolves in the water and CBM is unconventional natural gasas the associated mineral resource of coal. The studies of the factors affecting CBM wellproductivity and ECBM(Enhanced Coal Bed Methane Recovery) methods provide atheoretical basis for improving CBM well productivity.Hancheng mine district is located in the eastern part of Weibei Permo-Carboniferouscoal field and large quantities of CBM exists in the region with the density of1.21×108m3/km2(higher than the rest in China). The characteristics of the macerals,industrial components, pores and adsorption of the Hancheng coal were studiedexperimentally, then the effect of macerals and industrial components on the adsorptionwas acquired. According to index system principles, using the static and dynamicdevelopment parameters, the CBM well dynamic analysis index system and evaluationmethod were built. The coefficient of the CBM well production potential was determined,and its significance analyzed. According to the CBM well daily gas production, wells canbe divided into high, middle, low and none yield well, and similarly based on water,wells can also be divided into4types. According to the production data analysis,4production characteristics and8influence factors were summarized. Using the reservoirsimulation software ECLIPSE to simulate the CBM development, based on idealfive-point well pattern, and from the geological and engineering aspect, sensitivityanalysis about the influence factors on well production and a series of ECBM methodswere made. Finally, combined with the field production data, and analyzing the reasonsof low production, the corresponding integrated control measures were put forward.Research achievement has obtained desirable results in field application.