Calculation of water influx in interlayer of coal reservoir and controlled CBM reserves

The percolation mechanism of CBM reservoir differs from conventional ones, and its production is affected by desorption pressure and adsorption characteristics, it is difficult to calculate the controlled reserves of single well; because edge-bottom water or interbedded water are connected by fractures or faults, some wells have high water yield and long drainage period in initial production, show obvious water invasion characteristics. In order to assess the productivity and water invasion of CBM wells, through investigation of massive papers, this paper finds that there are few studies on calculating controlled reserves and water influx of single well. The paper innovatively uses a few of simple field data to calculate water influx of CBM wells and controlled reserves of single well, considers non-conventional features of reservoir and establishes corresponding production model by the method of pseudo geological reserves and production instruction curves. The result proves that this study performs effectively, approaches true reservoirs by two ways, and it is of great significance to instruct exploitation of CBM wells.