Method for determining stratum stack quality factor by direct scanning of prestack time migration

Abstract

The invention relates to a method for determining a stratum stack quality factor by direct scanning of prestack time migration. By modeling methods for defining an equivalent stack quality factor, developing and utilizing prestack reflection seismic data and scanning and inversely demonstrating the stratum stack quality factor, a series of constant-Q and inverse-Q filtering is selected and combined with the prestack time migration to high-efficiently compensate ground reflection data and acquire a common reflection point set; generalized S transform is used for accurately solving an instantaneous frequency spectrum of a stack channel; the minimum average derivative after a logarithmic spectrum is used as an automatic selection standard of a correct stack Q value, so rapid and automatic inverse demonstration and analysis of a stratum stack Q value is realized; and a method for inversely demonstrating and analyzing the stack Q value of the common reflection point set based on viscous compensation migration is established. The method is applied to reflection seismic data processing in seismic exploration, is used for providing important input parameters for high-resolution seismic imaging, and has important application value in exploration of deep concealed oil and gas and mineral resources in China.

Description

technical field [0001] The invention belongs to the technical field of reflection seismic data processing in seismic exploration of oil and gas fields and mineral resources, and is a technical means for obtaining important input parameter fields of high-resolution pre-stack seismic imaging. Background technique [0002] Stack Q value is an important parameter required for time-domain inverse Q filtering and prestack time migration in viscous media. Accurate inversion of stack Q value has important application value for high-resolution seismic data processing in the field. [0003] There are many Q value inversion methods, including time domain algorithm and frequency domain algorithm. The Q value inversion of the time-domain algorithm has poor accuracy, and the two most representative methods in the frequency-domain algorithm are: the logarithmic spectrum ratio method and the frequency shift method, both of which are based on the fact that viscous absorption is the only one ...

AI Technical Summary

Problems solved by technology

In addition to amplitude changes, the video frequency and phase of reflected seismic waves also change. In this case, the logarithmic spectrum ratio method and frequency shift method based on spectral changes will have a large error in Q value estimation

[0008] Third, compared with transmission data (such as VSP data), reflection data has a longer propagation path and further attenuates the amplitude, and its data is more susceptible to noise

In the past, the acquisition of seismic spectrum was realized by short-time Fourier transform, but the actual seismic data is a non-stationary signal, which makes the spectrum obtained by this method greatly distorted compared with the real sub-spectrum

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