Reverse time migration method and apparatus for VTI medium, and medium

Abstract

The invention provides a reverse time migration method and apparatus for a VTI medium, and a medium. The method comprises: a focus coordinate is extracted in shot gather data and a focus wavelet is generated; according to a forward modeling scheme, the focus wavelet is extended based on a qP wave fluctuation equation along the time forward direction, wherein a plurality of wave field parts are selected for storage during the extending process; extension is carried out by using the plurality of wave field parts based on the qP wave fluctuation equation along the reverse time direction, therebyobtaining a focus wave field; seismic data are extracted from the shot gather data and interpolated seismic data are extended along the reverse time direction based on the qP wave fluctuation equationto obtain a demodulator probe wave field; correlation imaging is carried out on the focus wave field and the demodulator probe wave field to obtain a shot migration profile, and the above-mentioned steps are performed to obtain a plurality of shot migration profiles; and the multiple shot migration profiles are superposed to obtain a final imaging profile. Therefore, under the circumstance that the computing load is reduced substantially, the longitudinal wave component of the same kinematic feature can be obtained and thus the accurate reflection event returning of the imaging profile is realized, and the imaging precision of the complex medium is improved.

Description

technical field [0001] The invention relates to the technical field of seismic survey, in particular to the field of reverse time migration method and equipment for VTI medium. Background technique [0002] Seismic exploration is one of the main means to search for oil and gas resources. In the field of exploration seismology, the early reverse time migration method proposed by Whitmore (1983) is one of the most effective means to obtain the subsurface structure. In recent years, due to the great progress of computer science and technology, the reverse time migration method has brought the possibility of industrialization. The reverse time migration method based on the acoustic wave equation is realized in isotropic media by using the finite difference numerical solution method. The oil and gas industry will The method is applied to actual production to provide strong technical support for increasing oil and gas production and storage. With the continuous deepening of oil a...

AI Technical Summary

Problems solved by technology

For the reverse time offset calculation of complex big data models, since the central processing unit has a logic control unit as the main part compared with the arithmetic unit in the architecture design of the central processing unit, it pays more attention to the judgment of logical relations, so the calculation of the central processing unit The ability has seriously affected the data processing ability, and the calculation cycle is even unacceptable. The time-consuming calculation of the reverse time migration algorithm using the central processing unit device has become the bottleneck of its industrial application.

[0007] Therefore, in the prior art, using the full elastic wave equation to perform migration calculations is too large to meet the actual needs of industrial production; in the case of drastic changes in anisotropy parameters, when using the quasi longitudinal wave equation obtained by the acoustic approximation method to solve the wave field There is instability; for large model data, the existing storage strategy cannot meet the storage requirements of the graphics processor

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