Intersection Determination Method for Sensitive Reference Frequency in Frequency-Dependent AVO Dispersion Parameter Inversion

Abstract

The invention is an oil and gas seismic exploration data processing and interpretation technology, which utilizes intersection analysis to directly select a sensitive reference frequency in frequency-dependent AVO dispersion parameter inversion. Firstly, within the seismic effective frequency range, the known logging interpretation data is fully used to constrain, and the P-wave dispersion attributes of the fluid-bearing reservoir section are projected on the frequency-dispersion attribute intersection plane graph, and the fluid-containing reservoir is determined through intersection analysis. The frequency corresponding to the maximum value of the P- and S-wave dispersion properties of the reservoir and the frequency or frequency band corresponding to the maximum difference in the P- and S-wave dispersion properties of different fluid reservoirs are the sensitive characteristic frequencies, and this frequency is used as the most sensitive The frequency-dependent inversion of AVO P- and S-wave dispersion attribute parameters for pre-stack angle gathers with optimal reference frequencies can maximize the seismic dispersion anomalies of fluid-bearing reservoirs, and maximize the dispersion differences of different fluid reservoirs, realizing Differentiation and identification of different fluids.

Description

technical field [0001] The invention relates to the field of oil and gas seismic exploration data processing and interpretation, and is a method to determine the reference frequency of the inversion through the intersection analysis method in the frequency-dependent AVO dispersion parameter inversion, so as to use this frequency as a sensitive reference frequency, and to Dispersion parameter inversion is performed on seismic prestack angle gathers to maximize the difference in seismic P- and S-wave dispersion when reservoirs contain different fluids, to distinguish different fluid reservoirs to the greatest extent, and to highlight the seismic dispersion anomalies of oil and gas reservoirs. Background technique [0002] AVO (Amplitude Versus Offset) uses the Zoeppritz equation to describe the variation of seismic wave reflection amplitude with incident angle (or offset), and is used to extract information about reservoir lithology, physical parameters and pore fluid. The tra...

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Problems solved by technology

However, at present, in the process of frequency-dependent AVO dispersion inversion using seismic pre-stack angle gathers, the method of selecting the reference frequency is usually the "manual observation method": first, the instantaneous spectral decomposition of the post-stack seismic data in the work area is performed, and several Common frequency profile, manually observe the characteristics of the instantaneous spectrum energy of the known oil and gas reservoirs changing with different frequencies in the common frequency profile, generally choose the frequency that is close to the main frequency of seismic data and the corresponding frequency of the oil and gas reservoir instantaneous spectrum energy is relatively strong as the reference frequency , this determination method is prone to strong human subjectivity; in addition, the dispersion anomaly information of different fluids reflected in the pre-stack angle gathers is easily distorted or weakened in the post-stack seismic data, so the use of post-stack data is not conducive to accurate Determining the more hydrocarbon-sensitive reference frequencies in prestack angle gather seismic data limits the accuracy and reliability of frequency-dependent AVO dispersion parameter inversions

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