A Seismic Multiwave Modeling Method Based on Inversion Framework

Abstract

The invention relates to a seismic multi-wave modeling method suitable for the inversion framework of multi-wave multi-component seismic data. The root velocity is converted into slice velocity using the Dix formula; the compressional and shear wave sensitivity matrix is ​​obtained, and the residual curvature of the angular gather is picked up by the automatic fitting method; the constrained least squares multi-wave modeling equation with regularization is constructed, and the modeling equation is solved to obtain the compressional wave and shear wave slowness update amount; the iterative termination conditions for velocity modeling are: the imaging depths of longitudinal waves and converted waves are consistent, and the residual curvature of the angular gather is zero. Its technical advantages are mainly reflected in the reliability of technical effects; it has low requirements on the initial velocity of the input, and has good compatibility with current oil and gas exploration software; it can generate pre-stack depth migration results as quality monitoring, and does not generate redundant calculations.

Description

technical field [0001] The invention belongs to the field of oil and gas exploration seismic data processing methods, in particular to a method applicable to multi-wave and multi-component seismic data for realizing multi-wave velocity modeling. Background technique [0002] In recent years, the exploration and development of some old oil areas in my country has become increasingly difficult, and the exploration targets have gradually shifted to fractured oil and gas reservoirs and lithologic oil and gas reservoirs. high demands. When dealing with multi-wave and multi-component seismic data in conventional seismic exploration, the vertical component is often treated as a longitudinal wave, and the horizontal component is treated as a converted shear wave for processing similar to a longitudinal wave. When implementing velocity modeling, the longitudinal wave is generally inverted first, and then In the shear wave inversion, the elastic vector wave characteristics of the seis...

AI Technical Summary

Problems solved by technology

When dealing with multi-wave and multi-component seismic data in conventional seismic exploration, the vertical component is often treated as a longitudinal wave, and the horizontal component is treated as a converted shear wave for processing similar to a longitudinal wave. When implementing velocity modeling, the longitudinal wave is generally inverted first, and then In the shear wave inversion, the elastic vector wave characteristics of the seismic wave are not considered in the whole process, and its processing effect largely depends on the accuracy of the wave field separation. If the energy of different wave types is not completely separated, the residual energy It will generate a lot of noise crosstalk in the imaging results, which will seriously affect the tomographic inversion effect

In fact, the earth medium is a heterogeneous, non-completely elastic, anisotropic, multiphase medium, in which the propagating seismic wave is an elastic wave, and the longitudinal and transverse waves are coupled together. The data processing method based on the acoustic wave assumption It is not suitable for multi-wave and multi-component data. If the seismic data processing method is not fundamentally changed, it is difficult to achieve a major oil and gas breakthrough

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