High resolution converted wave crack prediction method

Abstract

The present invention provides a high resolution converted wave crack prediction method. The method comprises the steps of acquiring the converted wave seismic data, and carrying out the pre-processing and the prestack migration to obtain a converted wave migration section; establishing a multi-thin layer objective function of sparse constraint and wave impedance constraint on the migration section; for the multi-thin layer objective function, utilizing the frequency domain mapping and L1-norm joint optimization algorithm to obtain a high-precision reflection coefficient; constructing a high frequency wavelet while keeping the high frequency wavelet have a determined frequency width, obtaining a high resolution converted wave migration section according to the high frequency wavelet and the high-precision reflection coefficient; utilizing an improved third generation characteristic value coherence volume calculation method to carry out the coherence data volume slice extraction on the high resolution converted wave migration section, thereby realizing the crack prediction. According to the present invention, the resolution of the extracted crack prediction section is higher, the crack trend is more clear, and the details are depicted more obviously.

Description

technical field [0001] The invention belongs to the technical field of converted wave seismic data processing, and specifically relates to a high-resolution converted wave fracture prediction method. Background technique [0002] At present, the fracture characterization of coherent volume is an important means to explore fractured reservoirs, and the acquisition of high-resolution data volumes and fracture parameters required for fracture prediction has always been a key research issue in the exploration of fractured reservoirs. Due to the characteristics of low signal-to-noise ratio and resolution of the wave, its resolution needs to be improved to facilitate the thin-layer resolution of subsequent interpretations. However, the conventional high-resolution processing method based on the assumption of minimum phase and white noise has a limited ability to improve the resolution of converted waves under the limitation of the main frequency band, and cannot meet the requireme...

AI Technical Summary

Problems solved by technology

M. Bahorich et al. proposed a cross-correlation coherence analysis algorithm on the amplitude, but the breakpoints calculated by this algorithm are fuzzy, with heavy noise and weak energy.

K.J.Marfurt proposed that the coherence algorithm based on similarity coefficient has the characteristics of good stability and high accuracy of fault description, but the disadvantage of low lateral resolution cannot be changed

Gersztenkorn et al. proposed an algorithm based on eigenstructure analysis, using Hilbert transform to calculate coherent volumes to improve its stability and noise resistance. However, when this algorithm is used in high and steep complex areas, it is not as good as the second-generation algorithm if the dip angle is not considered. If the inclination angle is considered, the calculation efficiency cannot be applied in production

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