A method for simulating electrical logging response of fractured-cavity reservoirs

Abstract

The invention belongs to the field of electrical logging numerical simulation, and discloses a method for simulating electrical logging responses of fracture-vuggy reservoirs. The method comprises the steps of: a. establishing an equivalent fractured-vuggy reservoir stratum model according to block geological data, and determining the basic parameters of the equivalent fractured-vuggy reservoir stratum model; b. according to the equivalent fractured-vuggy reservoir stratum model Establish the finite element functional of the direct current logging response; c. According to the finite element theory, perform grid discretization and resistivity assignment on the equivalent fracture-cavity reservoir formation model; d. Assemble and solve the finite element conductance array to obtain the depth Laterolog values. The method of the present invention solves the problem of cross-scale grid division of fractured-vuggy reservoirs, effectively delineates the boundary of fractured-vuggy reservoirs, scientifically realizes the numerical simulation of electrical logging of fractured-vuggy reservoirs, and is a method based on electrical logging data. The electrical logging identification and evaluation of carbonate and volcanic fracture-vuggy reservoirs provide a theoretical basis.

Description

technical field [0001] The invention belongs to the field of electrical logging numerical simulation, and relates to a method for simulating electrical logging responses of fracture-cavity reservoirs. Background technique [0002] Carbonate rocks, volcanic rocks and other oil and gas reservoirs are widely developed. Due to the characteristics of strong heterogeneity, obvious anisotropy, different scales and uneven distribution of fractures and caves, and large changes in filling types and filling degrees, the electrical logging response of fractured-vuggy reservoirs is complex, and it is easy to cause The ambiguity and ambiguity of logging evaluation results. [0003] At present, there are very few researches on electrical logging numerical simulation of fractured-cavity reservoirs at home and abroad. Faivre et al. conducted research on single fracture and parallel plate fracture models for fractured formations, and solved the numerical simulation problem of electrical log...

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Problems solved by technology

Faivre et al. conducted research on single fracture and parallel plate fracture models for fractured formations, and solved the numerical simulation problem of electrical logging in fractured formations. Combination fracture-vuggy reservoirs are not considered

[0004] At present, there are still the following difficulties in the numerical simulation of electrical logging response of fractured-vuggy reservoirs: (1) For geological problems such as fractures, caves, and fracture-cavity combinations, the mathematical model is single, and there is still a lack of suitable mathematical geological abstraction and analysis to meet The needs of actual geological conditions; (2) When commercial software is used to simulate the response of fractured-vuggy reservoirs, the cross-scale grid division from fractures as small as a few microns to tens of meters of strata will lead to a sharp increase in the number of grids. (3) At present, structured grid division and step approximation methods are widely used in electrical logging simulation, and the simulation accuracy of this method is low when dealing with fracture-cavity boundaries.

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