A Performance Optimization Method for Prestack Migration of Wave Equation Based on Mixed Base Discrete Fourier Transform

Abstract

The invention provides a wave equation prestack migration performance optimization method based on mixed base DFT (discrete Fourier transform ) and belongs to the field of the application and the research of the new oil-gas exploration physical geography technology in the geoscience. The method comprises the following steps that firstly, the relative optimum transform length and the calculation time are obtained through analyzing the relationship between the transform length and the transform time based on the mixed base DFT function, and a resource file is formed; then, the optimum transform length is obtained in a mode of finding a sequence table and the resource file according to the singe shot imaging range and the reference edge expanding number given by users; and finally, the two-dimensional Fourier transform time is relatively minimum through regulating the edge expanding range of the wave field extrapolation, so the calculation efficiency of the frequency-wavenumber domain wave equation prestack migration is improved. The wave equation prestack migration performance optimization method has the advantages that the two-dimensional Fourier transform time is reduced, the calculation efficiency of the single shot migration is improved, and in addition, the imaging quality is reduced. The wave equation prestack migration performance optimization method is provided by aiming at the SSF (space simulation facility) continuation operator, and can be completely expanded to all frequency-wavenumber domain one-way wave prestack migration algorithms.

Description

technical field [0001] The invention belongs to the application research field of new oil and gas exploration geophysics technology in earth science, and specifically relates to a method for optimizing the performance of wave equation pre-stack migration based on mixed-base discrete Fourier transform (DFT), which can ensure the quality of migration imaging In this case, the serial or parallel calculation efficiency of wave equation prestack migration can be effectively improved, and the processing cycle of exploration seismic data can be shortened. Background technique [0002] In recent years, with the in-depth study of oil and gas exploration and development and the rapid development of computer software and hardware technology, pre-stack depth migration based on wave equation has attracted more and more attention from the oil and gas exploration and development industry. Because the wave equation prestack depth migration method can describe the propagation characteristics...

AI Technical Summary

Problems solved by technology

At present, the most studied Fourier transforms are radix-4FFT, radix-8FFT, split-base FFT, prime factor FFT, Winogran Fourier transform, and arithmetic Fourier transform. Transformation speed, but both increase computational complexity or have other defects, so the most used Fourier transform is base 2 fast Fourier transform (base 2FFT)

However, when the transform length does not meet the power of 2, the base 2FFT needs to be filled with 0, which increases the amount of calculation and memory requirements

At the same time, the base 2FFT cannot perform DFT on the specified frequency point, and there are spectrum leakage and fence effects, and the mixed base FFT can just solve these defects of the base 2FFT

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