Nonlinear earthquake pre-stack elastic parameter inverting method based on regularization

Abstract

The invention provides a nonlinear earthquake pre-stack elastic parameter inverting method based on regularization. The method comprises the following steps of: obtaining a multi-angle ray elasticity impedance well curve REIi according to the known logging information and ray elasticity impedance; introducing the known position, the fault data and the multi-angle ray elasticity impedance well curve REIi to establish ray elasticity impedance models of the whole work area from different angles; calculating part superposition data bodies of different angles of incidence by using the pre-stack offset gather; inverting by virtue of a sparse pulse inverting algorithm to obtain a ray elasticity impedance data body corresponding to the angle of incidence; introducing the ray elasticity impedance data body corresponding to the angle of incidence into the nonlinear Landweber-Fridman iterative algorithm to obtain the longitudinal-transverse wave speed and rock density of the whole work area so as to calculate other lithology parameters. By utilizing the method, inversion calculation is carried out by using multi-angle REIi data and the nonlinear Landweber-Fridman iterative algorithm, so that accurate lithology parameters can be obtained.

Description

technical field [0001] The invention relates to the field of oil and gas seismic exploration, in particular to a regularization-based nonlinear seismic pre-stack elastic parameter inversion method. Background technique [0002] The traditional post-stack wave impedance inversion can obtain the wave impedance profile, which has a good effect in reservoir prediction. However, in recent years, with the continuous improvement of exploration accuracy and difficulty, the limitations of post-stack wave impedance inversion to solve geological problems have become more and more obvious. Based on this, pre-stack seismic inversion technology has received more and more attention, and has become a rising new technology in the field of geophysical exploration. [0003] Pre-stack seismic inversion technology makes full use of pre-stack information to obtain information on many other elastic parameters except wave impedance, which greatly enriches reservoir prediction methods and enhances ...

AI Technical Summary

Problems solved by technology

[0042] 1. Conventional post-stack inversion cannot obtain reliable wave impedance and other lithological information;

[0043] 2. Both elastic impedance EI and normalized EI depend on the speed ratio of S wave and P wave to keep a certain constant from shallow to deep, which is often inconsistent with reality;

[0044] 3. Elastic impedance EI and normalized EI generally require three offset data volumes to obtain the velocity and density of longitudinal and shear waves, and the anti-noise ability is relatively poor

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