RESEARCH ON THE IMPACT OF PRESSURE DISTRIBUTION ON WELL PATTERN ARRANGEMENT IN COAL-BED METHANE RESERVOIR

Coal-bed Methane reservoir mathematical model considering the coupling of matrix pore deformation and pore pressure during gas adsorption and desorption was established, Coal-bed Methane reservoir geologic model with igneous rocks and faults was established, Liujia low coal rank Coal-bed Methane block with multi-well exploitation was simulated. Simulation results show: pressure distribution of complexly geological CBM reservoir is influenced by geological structure. Critical desorption pressure was used to value pressure distribution, when the permeability of face cleat is identical with butt cleat, critical desorption pressure area and the output are larger, the differences of permeability between face cleat and butt cleat must be considered in the numerical simulation. Through the contrast of production under different well patterns in complicatedly geologic Coal-bed Methane reservoir, irregular quadrilateral well pattern can make use of the beneficial effects of geological factors most, capacity of this well pattern is the highest.