Mixed domain Fourier finite difference migration method based on coefficient optimization

Abstract

The invention provides a mixed domain Fourier finite difference prestack depth migration imaging method based on the coefficient optimization in order to improve the earthquake migration imaging accuracy of a complex high steep structure region and forcefully guide accurate prediction and exploitation of oil-gas resources. According to the method, wave field extrapolation operators are expanded through a pade approximation rational function, expanded coefficients are optimized through a Chebyshev polynomial, new wave field extrapolation operators are obtained trough deduction, relative errors between the new wave field extrapolation operators and wave equation accurate wave field extrapolation operators are reduced, the approach degree of the wave field extrapolation operators is increased, and the earthquake migration imaging accuracy of the complex high steep structure region is improved while computational efficiency is guaranteed. The imaging effect of the improved mixed domain Fourier finite difference migration method on the Marmousi model migration section is compared with that of a conventional Fourier finite difference migration method on the Marmousi model migration section, and it is proved that the mixed domain Fourier finite difference prestack depth migration imaging method obtained based on coefficient optimization has higher migration imaging accuracy. The method has important significance in improving the earthquake migration imaging accuracy of the complex high steep structure region.

Description

technical field [0001] The invention relates to the field of seismic exploration data processing, in particular to a pre-stack depth migration imaging processing technology. Background technique [0002] The conventional seismic migration imaging method is based on the assumption of a homogeneous isotropic elastic medium. However, with the deepening of oil and gas exploration in my country, the difficulty of exploration is increasing. Complex high and steep structural areas have become the focus of oil and gas exploration today. It is difficult to satisfy the assumptions of conventional seismic migration imaging methods at the same time with seismic raw data. Wave equation prestack depth migration has been rapidly developed as the most effective method for dealing with complex high and steep structural areas. [0003] The wave equation migration imaging technology started from the wave equation migration based on the finite difference approximate solution proposed by J.F.Cla...

AI Technical Summary

Problems solved by technology

From the adaptability of the wave equation migration continuation operator in the two domains, it can be seen that the wave equation migration imaging continuation operator in the single domain has certain limitations. Due to the influence of variable speed, the wave equation migration imaging method in a single domain is difficult to meet the precise imaging of complex structural areas

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