Basedonthe first-order Biot-equation with simplified coefficients,astaggered irregu- lar-grid finite difference method(FDM)is developed to simulate elastic wave propagation in 3-D heterogeneous anisotropic porous medi...Basedonthe first-order Biot-equation with simplified coefficients,astaggered irregu- lar-grid finite difference method(FDM)is developed to simulate elastic wave propagation in 3-D heterogeneous anisotropic porous media.The ‘slow’P wave in porous media wave simulation is highly dispersive.Finer grids are needed to get a precise wavefield calculation for models with curved interface and complex geometric structure.Fine grids in a global model greatly increase computation costs of regular grids scheme.Irregular fine or coarse grids in local fields not only cost less computing time than the conventional velocity-stress FDM,but also give a more accu- rate wavefield description.A dispersion analysis of the irregular-grid finite difference operator has confirmed the stability and high efficiency.The absorbing boundary condition is used to elimi- nate artificial reflections.Numerical examples show that this new irregular-grid finite difference method is of higher performance than conventional methods using regular rectangular grids in simulating elastic wave propagation in heterogeneous anisotropic porous media.展开更多
文摘Basedonthe first-order Biot-equation with simplified coefficients,astaggered irregu- lar-grid finite difference method(FDM)is developed to simulate elastic wave propagation in 3-D heterogeneous anisotropic porous media.The ‘slow’P wave in porous media wave simulation is highly dispersive.Finer grids are needed to get a precise wavefield calculation for models with curved interface and complex geometric structure.Fine grids in a global model greatly increase computation costs of regular grids scheme.Irregular fine or coarse grids in local fields not only cost less computing time than the conventional velocity-stress FDM,but also give a more accu- rate wavefield description.A dispersion analysis of the irregular-grid finite difference operator has confirmed the stability and high efficiency.The absorbing boundary condition is used to elimi- nate artificial reflections.Numerical examples show that this new irregular-grid finite difference method is of higher performance than conventional methods using regular rectangular grids in simulating elastic wave propagation in heterogeneous anisotropic porous media.
