Anisotropic numerical simulation of coal-bearing strata with finite-difference

Coal reservoir is a dual porous rock composed of matrix porosity and fracture with its unique cleat sys-tem.However,coal is usually assumed to be an isotropic medium in the traditional coal seismic exploration,and the impacts of fractures on seam are not taken into account.Elastic wave propagation of VTI(transversely isotropic with a vertical symmetry axis) and HTI(transversely isotropic with a horizontal symmetry axis) coal with different thicknesses were simulated by high-order finite-difference of staggered-grid respectively to obtain wave snapshots of homogeneous coal and seismic records of coal-bearing layered strata.By comparative analysis,it was found that evident differences of elastic wave propagation exists between VTI and HTI homogeneous coal,that changes in coal thickness are more sensitive to wave field than the changes in coal type from the layered seismic simulation records.