Method and device for calculating first arrival of seismic data of submarine cable

Abstract

The invention provides a method and a device for calculating the first arrival of seismic data of a submarine cable. The method comprises steps: the offset between a receiving point in a seismic data gather and a shot point is calculated; according to the offset and the determined seawater velocity, the direct wave first arrival travel time at each receiving point in the gather is calculated; according to a selected far offset correction factor, the far offset correction amount for the first arrival travel time is obtained through calculation; and the direct wave first arrival travel time and the far offset correction amount are added to obtain the first arrival removal time in the seismic data gather. By using each embodiment of the invention, boundaries of effective waves and interference waves can be distinguished accurately, refracted wave interference and direct wave interference are scientifically removed in the data, the interference wave component before the first arrival of the effective waves can be reasonably removed, the effective wave component can be kept maximally, and the accuracy and the rationality of seismic data analysis and the final imaging quality for the submarine cable can be ensured to be improved.

Description

technical field [0001] The invention belongs to the technical field of submarine cable seismic exploration data processing, and in particular relates to a first-arrival calculation method and device for submarine cable seismic data. Background technique [0002] With the development of resources such as oil and gas advancing day by day, the stamina of land resources is becoming more and more insufficient. The exploration and development of marine resources has increasingly become the focus of the development of earth resources in various countries. Therefore, the exploration work in shallow sea areas has become the key task in the early stage of exploration and development. [0003] At present, several submarine cable (OBC, Ocean Bottom Cable) seismic exploration projects are completed every year in shallow sea areas at home and abroad, and there will be more and more similar projects in the future. At present, when processing OBC seismic data, it is necessary to remove th...

AI Technical Summary

Problems solved by technology

Therefore, in the processing of submarine cable seismic exploration data, at present, simply referring to refracted waves cannot effectively and accurately remove the direct wave interference on seismic data.

[0004] The existing method of manually removing the first arrival interference on the submarine cable seismic records is highly subjective (mainly based on experience), has high learning costs, and has low accuracy and reliability.

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