Least square migration imaging method and device based on l-bfgs algorithm

Abstract

The invention discloses a least squares migration imaging method and device based on the L-BFGS algorithm. The method includes: performing reverse time migration imaging according to the acoustic wave velocity model of the target exploration area and the common shot point record of the acoustic wave velocity model to obtain Initial imaging results; calculate the synthetic seismic records of the target exploration area and the record residuals of the original observation records according to the initial imaging results; calculate the gradient of the target functional with respect to the initial imaging results according to the record residuals; The gradient of the imaging result is obtained by the L-BFGS algorithm to obtain the second imaging result; it is judged whether the recording residual and the calculation times of the L-BFGS algorithm meet the preset termination condition. The present invention avoids the optimization process falling into a local optimum in the process of solving the nonlinear optimization problem by introducing the optimization solution method of L-BFGS, so that the optimization process in the aspect of nonlinear optimization is more robust.

Description

technical field [0001] The invention relates to the technical field of geophysical exploration, in particular to a least squares migration imaging method and device based on an L-BFGS algorithm. Background technique [0002] At present, with the improvement of the demand for seismic exploration, the accuracy of underground structure imaging has correspondingly higher requirements. The existing traditional reverse time migration technology can perform relatively accurate imaging of complex subsurface structures, but it still cannot meet the high-fidelity imaging requirements of complex oil and gas reservoirs. In the prior art, the least squares reverse time migration imaging technology is often used. It is based on the inversion theory. It mainly establishes the relationship between the reflection coefficient and the seismic record function, and continuously iterates the imaging results, so that based on the imaging results The residual error between the demigration syntheti...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is that the imaging precision of the existing imaging technology in seismic exploration is not enough, and there is still a slow convergence speed in the nonlinear optimization problem solving method in the imaging process, and the optimal imaging result cannot be obtained

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