Numerical Simulation Of Seismic Wave And Analysis Of Wave Field's Character

The paper encircles the problem of numerical simulation of seismic wave and analysis of wave field's character, bases on the analysis and summarization of the former researches and productions, applies the high rank of finite difference method, respectively uses sound wave equation, elastic wave, vertical wave equation of dual-phase medium, Biot equation, BISQ equation and advanced BISQ equation, realizes the numerical simulation of seismic wave in the geological model systemically and analyses the character of the shot of wave field and single shot record of the numerical simulation and the dynamical character of the medium interface, in order to research ulteriorly the rules of the propagation of seismic wave and the influence of the parameters of the underground medium to the velocity and attenuation of seismic wave in the propagation, thereby provides the scientific evidence for the explanation of the seismic information.Firstly the dissertation uses the high rank arithmetic operators of finite difference method based on the basic sound wave equation and elastic wave equation, which can be applied to the single-phase medium model, and disperses the fluctuant equation, and analyses the stability and astringency, and numerically simulates the propagation of the seismic wave in the typical geological model and analyses the wave field's character.Secondly the dissertation researches the vertical wave equation in the dual-phase medium, Biot equation and BISQ equation, which are applicable to the propagation of the seismic in the dual-phase medium. Though the researches it validates the correctness and the authenticity of the BISQ theory. Combing the new theory of advanced BISQ model, the paper carries through the contrast of the simulation and analysis with the Biot model and the BISQ model, consequently makes sure the feasibility and the favorable value of application of the advanced BISQ model.In the last the paper bases on the Zoeppritz equation and equation group of reflect coefficient and transmission coefficient on the interface of the dual-phase medium, ratiocinates AVO equation of the dual-phase medium including several types of typical interfaces: the top of the reservoir, the bottom of the reservoir and the two tight rocks, and the relationship between parameters of dual-phase medium and velocity of the vertical wave and the horizontal wave, density, porous and kind of the fluid, it is a beneficial exploration for the practicability of the dual-phase AVO equation. At the same time the paper puts forward a simple expression of the reflect coefficient and transmission coefficient on the above interfaces on the particular condition that the seismic wave incidences vertically, it validates the correctness and the preferable foreground of application.