Method for extracting offset domain common imaging gathers based on reverse time migration

Abstract

The invention provides a method for extracting offset domain common imaging gathers based on reverse time migration and belongs to the field of seismic data imaging treatment. The method comprises the following steps: each computer node performs reverse time migration treatment on shot data to acquire a reverse time migration shot domain imaging data volume and saves the reverse time migration shot domain imaging data volume in a local disk of the computer node; common imaging gathers of the multi-node-based reverse time shot domain imaging data are extracted. The method overcomes the defects that all common imaging gather data volumes cannot be saved in the internal memory of a computer, makes the best of available internal memory resources of the computer, reduces the I / O operation workload of the disk, enables lots of I / O operations to be shared by multiple nodes, and realizes efficient extraction of the reverse time migration offset domain common imaging gathers.

Description

technical field [0001] The invention belongs to the field of imaging processing of seismic data, and in particular relates to a method for extracting common imaging point gathers in the reverse time migration offset domain. Background technique [0002] Reverse time migration (Reverse time migration, RTM) is based on the two-way wave equation, which has the advantages of both integral migration and one-way wave migration. It can deal with the imaging problems of complex structures and violently variable media, and has a wide range of applications in production. value. Common imaging point gathers based on reverse time migration can be used for resection stacking, migration velocity analysis, AVO analysis, etc. Common imaging point gathers in reverse time migration include two types, common imaging point gathers in angle domain and common imaging point gathers in offset domain. The former has advanced theory and high precision, but it needs to calculate the wavefront direct...

AI Technical Summary

Problems solved by technology

[0003] Aiming at the problems of frequent I / O operations and low operation efficiency in the extraction of common imaging point gathers in reverse time migration offset domain, the present invention provides a method for extracting common imaging point gathers in reverse time migration offset domain, aiming at For the problem that the amount of reverse-time migration shot domain imaging data is too large and the efficiency of single-node extraction is low, the idea of ​​multi-node parallel gather extraction is adopted; in view of the problem that the computer memory is not enough to store all the gather data volumes, the data index is used The common imaging point gathers are extracted in blocks using the method, and the available memory of the computer is fully utilized to realize the high-efficiency extraction of the common imaging point gathers in the reverse time migration offset domain.

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