The Research Of Coalbed Methane Accumulation Zone About Jixi Basin

In Jixi Basin CBM resource is rich and has a broad prospect for CBM development. Theevaluation and optimization of the effective accumulation area for Coalbed Methane (CBM) is avery important basic work in the process of CBM exploration and development, and the resultsdirectly determine the success or failure of CBM development.In this paper, aiming at Jixi Basin, the regional rock mechanics and physical parameterstest on its core are conducted, and through the single-triaxial compression experiments of coaland rock, the Poisson’s ratio and elastic modulus are measured. By testing the permeability ofcoal and rock under different stress field and temperature field, their mathematical physicsequations is set up. According to the geological data, logging data and test data of Lishu TownDepression in Jixi Basin the single-well coal seam distribution layers, burial depth andthickness of20Wells are counted totally, the regional development situations of the differentcoal layers are analyzed; the evolution degree and coal quality characteristic of the target areacoal is studied, and the contour maps of the spatial distribution characteristics of each layer isdrawn.According to the cores, logs, seismic data and others of these areas, the distributioncharacteristics of formation strata and lithology and the structural distribution features of faultand fracture are determined, and the three-dimensional geological model of the target area isbuilt. Using the numerical analysis method, the distribution characteristics of the block stressfield are inversed; establishing the relation model and the mathematical physics equations of theground stress field, geothermal field and the coal rock permeability, the distributioncharacteristics of regional permeability are predicted, and the location of the relative highpermeability region is marked out; simulating the regional hydrodynamic conditions, therelative high reservoir pressure area is determined.Based on the determination of the main controlling factors of CBM reservoir-rich region,the evaluation area is classified. Applying the fuzzy matter-element evaluation method, theoptimal block of reservoir-rich region is screened out. It can provide guidance for Jixi basins toselect CBM accumulation zone.