First-arrival travel time picking method and device for seismic signal comprising noise

Abstract

The invention discloses a first-arrival travel time picking method and device for a seismic signal comprising noise, and the method comprises the following steps: carrying out the decomposition of an original seismic signal s(t) comprising noise through a noise adaption complete set EMD (Empirical Mode Decomposition) method, and obtaining a series of finite IMF components from high frequency to low frequency and residual components; screening out a plurality of high-frequency IMF components according to an EIF effective index function, and carrying out the wavelet threshold denoising; carrying out the accumulation and reconstruction of the high-frequency IMF components denoised through wavelet threshold denoising and the high-frequency IMF components which are not denoised, i.e., obtaining the denoised seismic signal x(t); initially determining the first-arrival travel time t0 through an improved sliding time window energy ration method; calculating a local extreme value in a time window comprising the moment t0 through an AIC information criterion method, wherein the time corresponding to the extreme value is the precise first-arrival travel time t. According to the invention, the method can effectively improve the seismic noise inhibition effect and improve the picking precision of the first-arrival travel time, and creates the conditions for the accurate processing and explanation of the subsequent seismic data.

Description

technical field [0001] The invention relates to the technical field of seismic data processing in geophysical exploration, in particular to a method and device for picking up the first arrival travel time of noisy seismic signals. Background technique [0002] The propagation of seismic waves in a limited-area medium takes time, and the first-arrival data of the seismic signal when it propagates from the source (excitation point) to the receiver (detection point) contains the physical characteristics (state, density, etc.) inside the medium. First arrival wave (P wave) travel time picking of seismic records is a basic and important work in seismic tomography forward modeling and static correction technology, which is of great significance for source location, reservoir description, and geological defect distribution detection. The manual picking of first arrival travel times is no longer in line with the needs of large-scale seismic exploration data today. The general compu...

AI Technical Summary

Problems solved by technology

[0003] The object of the present invention is to provide a method and device for picking up the first-arrival time of noisy seismic signals to solve the problem that it is difficult to obtain accurate first-arrival time when there is random noise interference in natural or artificial seismic data. Noise ratio, improving the accuracy of seismic first arrival travel time picking

Images