Fast sorting method of common offset vector (COV) gather of wide-azimuth seismic data at sea

Abstract

The invention relates to a fast sorting method of Common offset vector (COV) gather of wide-azimuth seismic data at sea. According to the method, all COV gathers in a whole area are sorted through each explosive wire, the whole explosive wire data is put in a memory, the whole sorting process is executed in the memory, then all COV gathers are output once. Disc data I / O is reduced to the greatestextent, and all COV gathers can be sorted by traversing seismic data once; in addition, the method uses a three-level optimized index table retrieval algorithm, that is, i navigation, whole area indextable+ii explosive wire secondary level index table+iii compression index table C, so that massive seismic data COV gathers are searched at a much higher speed, and the execution efficiency is high.The method has is highly practical, reliable and efficient in running, and can sort and process COV gathers of wide-azimuth seismic data at sea rapidly.

Description

technical field [0001] The invention relates to a COV gather sorting method, in particular to a COV gather quick sorting method of marine wide-azimuth seismic data, which belongs to the field of oil and natural gas seismic exploration. Background technique [0002] Due to the narrow exploration azimuth angle of traditional offshore streamer 3D seismic exploration, a large number of reflection signals from the lateral target body are lost during data acquisition. Therefore, in areas with particularly complex structures or azimuthal anisotropy, it is difficult to obtain the required exploration target. Raw seismic data. Faced with this dilemma, marine wide-azimuth seismic exploration technology came into being. OBC (Ocean Bottom Cable, submarine cable) seismic acquisition technology is currently a relatively economical acquisition technology for wide-azimuth seismic exploration at sea. When the ratio of the receiving line arrangement (horizontal) to the gun line arrangement (...

AI Technical Summary

Problems solved by technology

[0003] At present, although some commercial seismic data processing software (such as Geovation of CGG Company and Geoeast of BGP Company, etc.) have begun to provide COV gather sorting processing modules, the implementation details of their methods are strictly kept secret

However, other monographs and papers related to wide-azimuth seismic exploration technology rarely describe the COV gather sorting technology in detail.

COV gather sorting is essentially a sorting and classification problem, but the actual offshore wide-azimuth seismic data COV gather sorting also needs to consider the following issues: ①The seismic data volume is huge (at least TB level), and the COV gather sorting It is very time-consuming; ②COV gathers are a single coverage of the exploration area, and each COV gather needs to traverse the seismic data volume to extract each COV gather; ③There are missing traces and supplementary lines, and the receiving line and shot line often deviate from the preset position. Uneven seismic trace plane distribution

Among them, searching for target gathers in very large seismic data volumes (problems ① and ②) means a lot of disk I / O, and the more frequent the disk I / O, the lower the execution efficiency of the algorithm

And the various special cases contained in the problem ③ greatly increase the complexity of the COV gather sorting algorithm

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