Fluid identification method and system based on fluid bulk modulus AVO inversion

Abstract

The invention provides a fluid identification method and system based on fluid bulk modulus AVO inversion. The method includes the steps of collecting pre-stack seismic data, logging data and geological finding data of a target reservoir, building an AVO approximation formula representing a fluid bulk modulus, extracting wavelets according to the pre-stack seismic data, the logging data, the geological finding data and the AVO approximation formula representing the fluid bulk modulus, determining a fluid bulk modulus data body according to the pre-stack seismic data, the logging data, the geological finding data and the wavelets, and recognizing the type of fluid in current reservoir gaps according to the fluid bulk modulus data body. AVO inversion is performed through the AVO approximation formula representing the fluid bulk modulus so that fluid bulk modulus parameters can be estimated, fluid recognition illusion is avoided, and reliability of reservoir gap fluid type prediction is improved.

Description

technical field [0001] The present invention relates to the field of petroleum geophysical exploration, in particular to the pre-stack seismic inversion technology, specifically a method and system for fluid identification based on fluid bulk modulus AVO inversion. Background technique [0002] Since the 1970s, due to the digitization of seismic technology and the rapid development of computer technology, the use of seismic wave dynamics for reservoir prediction and fluid identification has become a research hotspot in the petroleum industry. Among them, the AVO (Amplitude Versus Offset, amplitude versus offset) inversion technology is a mainstream technology for predicting subsurface lithology and fluid-bearing properties based on the variation of amplitude versus offset. The coefficient changes with the incident angle to extract the required elastic parameters. The theoretical basis is the Zoeppritz equation describing the reflection and transmission of plane waves at the ...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the problem existing in the prior art that rock elastic parameters estimated based on conventional AVO are affected by solid-liquid coupling characteristics and easily produce false identification of fluid in reservoirs, the present invention provides a fluid based on fluid bulk modulus AVO inversion The identification method and system realize the separation of the fluid bulk modulus parameters in the reflection coefficient approximation, the fluid bulk modulus is more sensitive to the reservoir fluid information, and the AVO inversion can be used to estimate the fluid bulk modulus Bulk modulus parameters to avoid fluid identification artifacts and improve the reliability of reservoir pore fluid type prediction

Images