Scattering theory-based precondition least square method prestack seismic AVO record synthesis method

Abstract

The invention relates to a scattering theory-based precondition least square method prestack seismic AVO record synthesis method, which comprises the following steps: 1, extracting angle-dependent seismic wavelets, and performing Fourier transform on the seismic wavelets to obtain frequency spectrums of the seismic wavelets; 2, performing scale coarsening on the acoustic logging data and the density logging data which are subjected to depth sampling to obtain logging data under an earthquake scale; 3, calculating a Green function corresponding to the background model; 4, obtaining the product of the green function of the corresponding frequency and the seismic wavelet frequency spectrum; 5, solving a speed and density comparison function; 6, performing primary calculation by using a precondition least square method to obtain a full wave field including all propagation effects, and subtracting the background wave field from the full wave field to obtain a scattered wave field; and 7, obtaining a pre-stack seismic record of a time domain through Fourier inversion. According to the method, the problem that in the inversion process, the calculation amount of multiple times of forward modeling needs to be carried out is solved, and the calculation precision of an existing pre-stack earthquake AVO channel set synthesis method is improved.

Description

technical field [0001] The invention belongs to the field of forward simulation of seismic wave equations in oil exploration, and in particular relates to a method for synthesizing pre-stack seismic AVO records based on scattering theory preconditioning least square method. Background technique [0002] Seismic exploration is an important exploration method widely used in underground exploration to find out the structural information of underground strata and the distribution of oil and gas. It is through the collection of field seismic data, at a specific ground grid position, a large number of common shot reflection wave data carrying geological interface information can be obtained, and then, through a process called angle gather sorting, It is possible to obtain the seismic record of the seismic amplitude changing with the angle, that is, the pre-stack seismic AVA (amplitude versaangle) record. At the same time, each angle corresponds to a shot point and receiver point d...

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Problems solved by technology

[0010] The purpose of the present invention is to provide a pre-stack seismic AVO record synthesis method based on the scattering theory preconditioning least squares method, to solve the calculation amount of multiple forward modeling simulations in the inversion process, and to improve the existing pre-stack seismic AVO record synthesis method. Technical Problems of Calculation Accuracy of Set Synthesis Method

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