Method and system for effective reservoir forward modeling based on dual-phase media

Abstract

The invention discloses an effective reservoir forward modeling method and system based on two-phase media. The method comprises the following steps: determining reservoir formation physical property lower limit of reservoir, and classifying the reservoir higher than the reservoir formation physical property lower limit into effective reservoir; calculating longitudinal wave velocity of a rock skeleton and longitudinal wave velocity of fluid in the effective reservoir; according to the longitudinal wave velocity of the rock skeleton and the longitudinal wave velocity of the fluid, calculating reflection coefficient of the rock skeleton and reflection coefficient of the fluid; and carrying out convolution on the reflection coefficient of the rock skeleton and the reflection coefficient of the fluid and actual seismic wavelets respectively, and superposing forward modeling results obtained after convolution to obtain a seismic forward model of the effective reservoir. The effective reservoir forward modeling method and system based on the two-phase media expand technical applicability, improve forward modeling precision and goodness of fit in reservoir description and improve fluid identification capability in the reservoir, and are not only suitable for high-porosity and high-permeability oil and gas reservoir in shallow stratum, but also suitable for low-porosity and low-permeability oil and gas reservoir in deep stratum and special lithological layers.

Description

technical field [0001] The invention relates to a method and system for effective reservoir forward modeling based on dual-phase media. Background technique [0002] At present, the seismic reservoir forward modeling technology on the market is mainly based on the single-phase medium convolution model. The single-phase medium convolution model is a relatively simplified geological model, which helps to simplify the analysis and processing of complex geological problems. Since the single-phase media convolution model ignores the anisotropy characteristics of pore fluids, the actual reservoir forward modeling technology based on this model only considers the reflection characteristics of the rock skeleton of the reservoir, and the obtained forward modeling results can only reflect the rock skeleton of the reservoir. Sexual skeleton characteristics. [0003] The single-phase media convolution model assumes that the reservoir is a homogeneous single-velocity model, so the veloc...

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Problems solved by technology

[0004] The traditional single-phase media convolution model has the following disadvantages: (1) It is only suitable for high-porosity and high-permeability reservoirs, not for low-porosity and low-permeability reservoirs; (2) As the burial depth increases, Larger, the degree of compaction is strengthened, and the smaller the porosity, the smaller the impact of the fluid on the reservoir velocity, resulting in the same reflection coefficient of the oil layer and the water layer, the existing single-phase media convolution model can only reflect the reservoir The overall morphological characteristics of the rock skeleton make it difficult to further refine and distinguish the reservoirs, and do not have the ability to identify effective and ineffective reservoirs

It is not suitable for oil and gas reservoirs with low porosity and low permeability

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