A Method of Directly Extracting P-wave Time Domain Converted Wave Angle Gather

Abstract

The invention relates to seismic data processing, in particular to a method of directly extracting longitudinal wave time domain converted wave angle gather. Multi-wave and multi-component seismic disposal forms rectified gather of normal time difference with amplitude varying with offset. The rectified speed, the vertical speed ratio and the effective speed ratio of a transverse wave reflective converted wave time difference are obtained through speed analysis. The thickness of each layer, inter-layer longitudinal waves and transverse wave speed parameters of layered media are calculated by using a Dix formula. Ray tracing calculates longitudinal wave incidence, a transverse wave reflective converted wave incidence angle and corresponding longitudinal wave reflective time of each sampling point. The sampling points are placed on the longitudinal wave reflective time of the angle gather of a converted wave incidence angle to obtain the longitudinal wave incidence of longitudinal wave time domain and the angle gather of the transverse wave reflective converted wave. The method of directly extracting the longitudinal wave time domain converted wave angle gather simplifies multi-component information united explanation flow, and obtained converted wave angle gather can be directly used for AVO inversion of converted waves and can also be directly used for AVO inversion of multiple waves.

Description

Technical field [0001] The invention relates to the technical field of seismic exploration, and is a method for directly extracting longitudinal wave time-domain converted wave angle gathers in seismic data processing. Background technique [0002] In conventional seismic exploration, longitudinal wave data is used for exploration. Compared with conventional single longitudinal wave exploration, multi-wave multi-component seismic data comprehensively utilizes longitudinal wave and converted wave data to provide richer seismic attribute information, which can improve parameter estimation and reservoir prediction accuracy, and reduce exploration risk and uncertainty. It can fully reflect the elasticity of the underground medium and the lithology information of the formation. In longitudinal wave data, both downward and upward waves are longitudinal waves; but in converted wave data, downward waves are longitudinal waves, and upward waves are transverse waves ( figure 1 , Longitudi...

AI Technical Summary

Problems solved by technology

If the converted wave angle gathers in the converted wave time domain are directly extracted and AVO analysis is performed, the results cannot be directly combined with the longitudinal wave AVO attributes, and these attributes need to be transformed into the longitudinal wave time domain; if the extracted converted wave time domain angle gathers It not only needs a large amount of computer resources, but also causes error accumulation, which reduces the accuracy of angle gather extraction; moreover, if the compression factor is inappropriate, the converted wave time after compression will be incorrect.

Images