A Seismic Inversion Method for Carbonate Rock Physical Parameters

Abstract

The invention provides a carbonate rock physical parameter seismic inversion method, which belongs to the field of petroleum geophysical exploration. The method comprises the following steps: (1) carrying out pre-stack AVO three-parameter inversion based on a pre-stack angle gather to obtain formation elasticity parameters M, wherein M includes P-wave velocity, S-wave velocity and density; (2) establishing a statistical rock physical model based on logging data; (3) randomly simulating physical conditions of a reservoir based on the rock physical model obtained from step (2) to obtain a random simulation result; and (4) carrying out Bayes classified simulation on the random simulation result obtained from step (3) to obtain a posterior probability distribution, and taking the M obtained from step (1) as the input of inversion to find a R with the maximum posteriori probability distribution, wherein R is the final inversion result.

Description

technical field [0001] The invention belongs to the field of petroleum geophysical exploration, and in particular relates to a method for seismic inversion of rock physical parameters of carbonate rocks. Based on an improved Xu&White model, simultaneous inversion of various rock physical parameters of carbonate rocks based on seismic data is realized. Background technique [0002] With the continuous deepening of oil and gas exploration, new exploration blocks and new fields are constantly emerging, and with the successive discovery of large marine oil and gas fields in the south and west, marine carbonate rock oil and gas exploration has become an important part of oil and gas exploration in my country , so the comprehensive interpretation of carbonate reservoirs and fluids has become a key research topic that geophysicists pay more and more attention to. [0003] Reservoir prediction and fluid detection based on seismic data must be based on rock physics research. Seismic ...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art, and provide a method for seismic inversion of rock physical parameters of carbonate rocks. Aiming at the deficiencies of existing rock physical parameter seismic inversion technology for complex reservoirs, the focus is on In the inversion of rock physical parameters of carbonate rocks, due to the lack of stability of lateral extrapolation due to unclear rock physical relationships, through the study of rock physical models suitable for carbonate rocks, combined with statistical theory to establish statistics suitable for lateral extrapolation The petrophysical model uses stochastic simulation methods and nonlinear inversion methods to comprehensively apply geological, logging, and seismic data, and finally obtains a variety of petrophysical parameters, including mineral content, porosity, and fluid saturation. Content reveals lithology, while porosity and fluid saturation allow for a more granular evaluation of reservoirs

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