Longitudinal wave and converted wave prestack joint inversion method and system

Abstract

The invention discloses a longitudinal wave and converted wave prestack joint inversion method and system. The method comprises the steps that a longitudinal wave angle gather and a converted wave angle gather are input; longitudinal wavelets and converted wavelets at all angles are extracted; an initial elasticity parameter model of a longitudinal wave time domain is established; a longitudinal wave synthesis record error of the longitudinal wave time domain is calculated; a time-displacement operator matrix and an error back-propagation operator matrix are calculated; a converted wave synthesis record error of a converted wave time domain is calculated; a total error of longitudinal waves and converted waves in the longitudinal wave time domain is calculated; if the total error is smaller than or equal to a set error threshold value, an elasticity parameter inversion result is output; and if the total error is greater than the set error threshold value, a logarithmic elasticity parameter model of the longitudinal wave time domain is updated. Through the method and system, longitudinal wave and converted wave prestack joint inversion in which longitudinal waves and transverse waves are precisely and automatically matched is realized, the precise and stable elasticity parameter inversion result is acquired, and reservoir prediction precision is improved.

Description

technical field [0001] The invention relates to the technical field of oil and gas geophysics, and more specifically, to a method and system for combined prestack inversion of longitudinal waves and converted waves. Background technique [0002] Multi-wave seismic exploration is a very potential method for the exploration of lithologic and subtle oil and gas reservoirs. Although great progress has been made in the research and practical application of multi-wave multi-component seismic exploration technology in the world, there has been no significant progress, and it has become a "bottleneck" restricting the further development of multi-wave seismic exploration technology. The matching of multi-wave data, the joint inversion of multi-wave data, the comprehensive interpretation of multi-wave and the geological application of full-wave attributes have always been the focus and difficulty of multi-wave seismic interpretation, reservoir prediction and gas-bearing prediction. ...

AI Technical Summary

Problems solved by technology

If the sub-layers of the reservoir segment are matched incorrectly, it will lead to errors in the joint inversion results

The existing P-wave and converted-wave matching methods based on the principle of waveform similarity can basically achieve the matching of the main marker layers, but it is difficult to achieve accurate matching of small layers in the reservoir section, so it directly affects the accuracy of the joint inversion results of the reservoir section

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