Numerical Simulation Of Seismic Reflection Wave Field About Thin Interbedding

The central and Western Chinese underground formation are mostly sand lacustrine sediments, soil, most of the oil basin is mostly in sand, mudstone. These lacustrine sediments and lithology and thickness of the oil and gas basins of the change in the transverse direction is large and the thickness of the thin interbedding. And nowadays, the theory of thin interbedding is less. So it is necessary to study the numerical simulation of the thin layer, research the lacustrine subsurface structure and predict the spatial distribution of thin reservoir improving the seismic thin layer exploration, it has certain theoretical and practical significance.The seismic wave field numerical simulation method mainly consists of three ways: the seismic wave equation numerical solution, the ray tracing method, the integral equation method. Finite difference numerical simulation method is the main solution of wave equation. This method is widely used for the fast calculation and the application of isotropic medium. In this paper, i use the stress wave-velocity wave equation, first-order in time eight-order in space of the finite difference method of the numerical simulation to study and simulate the seismic wave field in the thin layer of the ground floor.This paper is based on the previous manual, firstly, a simple wavelet convolution simulation is performed, draw a conclusion. Secondly establishing wave equation, deriving the difference approximation of the first-order in the time and the eight-order in space of the wave equation, and give the difference schemes for the regular grid of the elastic wave equation of homogeneous medium, derivation and discussion of the solution of high-order difference between the staggered grid of the stress wave equation specificly, and it’s program. Analyzing the boundary conditions, stability conditions and frequency dispersion of seismic wave field numerical simulation, and determining the appropriate seismic parameters(Wave velocity, wavelet frequency, the size of finite difference mesh). On the basis of this, which i did numerical simulation of seismic wave field of thin layer and thin layer of seismic. In the interpretation and analysis of the simulation results, according to analyzed the amplitude of seismic wave, concluding the properties of the reflection wave field of the thin interbedding and the thin interbedding of the earthquake,and reflection wave energy superposition characteristics of thin interbedding. The final results are: The thin interbedding groups the rhythm type and the change type which meet a certain conditions in the layer thickness and layer number, the thin interbedding has a strengthening effect on the reflected wave; The above research analysis and inference of Xi’an underground to Quaternary lacustrine sediments as the medium of thin interbedding of reflected wave has strengthened; It is concluded that the abundance of reflected wave in the artificial seismic exploration records in Xi’an area is caused by the wave energy superposition between the thin and inter layer groups, which are different from the series of wave impedance.