Automatic seismic data first-arrival wave pickup method with strong background noise resistance

Abstract

The invention discloses an automatic first-arrival wave pickup method for the processing of geophysical prospecting seismic data, which comprises the steps of: selecting the length of sample points as a time window; limiting the first-arrival wave of the whole one shot in the time window; evaluating an average value of the amplitude of the time window; performing Hilbert transformation on data inthe time window except for the average value; evaluating mean square roots before and after the transformation to obtain envelope data; giving the length of a sample point to the envelope data; calculating the sum of squares of the envelope data of the sample point toward a direction with small envelope data from one sample point; and then calculating the sum of squares toward a direction with large envelope data, wherein the corresponding time of the sample point with maximum specific value on the envelope data is first-arrival time of the pickup. Compared with the prior automatic pickup method for first-arrival wave with maximum energy, the method has high precision and strong background noise resistance, can more meet the requirement on the pickup precision of the first-arrival wave inseismic prospecting technology, and can also reduce the workload of manually modifying the pickup of the first-arrival wave to a great extent at the same time.

Description

technical field [0001] The invention relates to a method for processing seismic data of geophysical exploration, in particular to a method for automatically picking up first-arrival waves of seismic data with strong background noise resistance. Background technique [0002] In land seismic data processing, it is very important to accurately pick up the first arrival wave, which is the basis for calculating the static correction of the surface low-velocity zone. In the field of exploration where surface velocity changes are relatively complex, using first arrival wave information to invert surface velocity and even directly estimate static correction has become the most conventional geophysical exploration technology to improve the imaging quality of seismic data. [0003] In offshore exploration, the first arrival information can be used to relocate the seismic source to solve the problem of observation point drift caused by sea waves. It can be said that many techniques in...

AI Technical Summary

Problems solved by technology

[0004] When collecting seismic data in the field of seismic exploration, due to the excitation of the surface source, the receiving conditions of the geophone and the surrounding environment, the first arrival wave of the seismic data collected in the field is difficult to be free from the influence of various noises. The influence of this noise is to a large extent This reduces the accuracy of the automatic first-arrival picking of the conventional maximum energy method, and human intervention is required afterwards

However, when the picking effect of first arrivals is poor and the amount of seismic data is relatively large, the workload of manually modifying the first arrivals will be heavy, and manual operations will also generate new errors and reduce the picking accuracy

Images