The Study Of Numerical Simulation Of Seismic Wave In Attenuation Medium And Extraction Of Absorption Properties

As the earth is not perfectly elastic actually, seismic waves traveling in the earth experience amplitude attenuation and velocity dispersion because of earth attenuation. Absorption is related to the properties of rocks, such as lithology, permeability, porosity, saturation and the type of fluid content. As one of the leading-edge topics in seismology study, seismic attenuation study is of theoretical and practical significance for the response characteristics of seismic wave attenuation properties and absorption and attenuation properties extract from seismic data.Wave field propagator in attenuation medium is the foundation of one-way wave equation modeling. In this paper, based on Futterman equation, we combine the quality factor Q, a parameter for quantitative characterization of absorption and attenuation, with the P wave propagation operator in elastic medium. We derive the wave propagation equation with complex wave number in attenuation medium using one-way wave equation, and then we establish SSF and FFD operator in attenuation medium.On the basis of the theory of wave propagation by one-way wave equation in attenuation medium, using physical principles of the reflected wave propagation, this paper achieve nonzero-offset seismic pre-stack forward modeling and migration in attenuation medium by one-way wave equation, which greatly improves the computation efficiency. With numerical simulation, we compare the characteristics of one-way wave equation and two-way wave equation and explore seismic wave propagation in the attenuation medium. On this basis, this paper built seismic wave propagation characteristics in different attenuation media. Attenuation estimated from seismic data is important for it relates to lithology, permeability, porosity, saturation and the type of fluid content. In this paper, based on S transform time-frequency analysis, we derived appear quality factor in different offset and the relationship of absorption coefficient with the offset. As seismic energy of high frequency and low frequency is asymmetric in attenuation medium, we compute the relative effective absorption coefficient,and derive association of relative absorption coefficient with offset. Through the use of multi-trace or lateral window we obtain zero-offset stratum relative absorption coefficient. The application in synthetic data and practical data demonstrate the feasibility of the method.