The Study Of Forward Modeling Method For Complex Reservoir Contains Fluid

In the point of seismic wave's propagation characteristics, the seismic numerical simulation of wave equation can be divided into the two-way wave equation method and the one-way wave equation method. The seismic numerical simulation of two-way wave equation usually using finite difference method(FDM), and the seismic numerical simulation of one-way wave equation is calculated in the Fourier domain.This paper first studied the finite difference method of double wavelength of the wave equation numerical simulation method. This paper have discussed the finite difference discretization scheme of regular grid and staggered grid of two-way wave equation, and compared and analyzed the advantages and disadvantages of these two kinds of grid by modeling computation. Then, the source loading mode of acoustic wave equation and elastic wave equation have been discussed. The numerical simulating and wave-field characteristics have been analyzed too. The absorbing boundaries which was widely used in numerical simulating have been analyzed in this paper. They are paraxial axial approximation method, transparent boundary condition, sponge absorbing boundary and the PML boundary condition. Numerical simulation example shows that under the same conditions the staggered-mesh accuracy compared with the regular grid; With high order difference scheme and the smaller the grid spacing can suppress dispersion phenomenon, but the expense to increase the amount of calculation; Compared with other kinds of boundary conditions, the boundary of the PML absorption effect is best.And then studied the one-way wave equation based on frequency wavenumber domain numerical simulation method. This paper has introduced three types of imaging principle, and three methods has been implemented: vertical variable phase shift method, split-step Fourier method, and the phase shift plus interpolation method which can meet the conditions of transverse speed. The numerical examples shows that it is a quick effective forward modeling method. Compared to the FDM, this method can solve the boundary problem more easily. It have good numerical stability, weak frequency dispersion, and it can bring to the result of high noise ratio seismic numerical simulation.Underground medium is often complex, the method which use acoustic wave equation to describe the propagation feature of seismic in underground have large approximation. It may lead to the inaccuracy and irrationality of seismic data processing and interpretation. Seismic exploration is more concerned in the seismic response characteristics of underground fluid reservoir, the numerical simulation can help us better understand the transmission mechanism of seismic wave in underground complex reservoir. On the related exploration, this paper combined with viscous- diffusive wave equation forward modeling and the related theory of fluid of complex reservoir seismic response characteristics, and analyze the relevant parameters are discussed.Finally,the one-way wave equation based on frequency wavenumber domain numerical simulation method has been chosed for the seismic numerical modeling of the pearl river mouth basin reefs geological model, as well as to the actual reef reservoir under the control of the sequence framework. According to the numerical simulation results and actual seismic profile, deepened the understanding of the work area with different seismic facies belt characteristics.