Method for simulating fracture-vug type reservoir body electric logging response

Abstract

The invention belongs to the field of electric logging value simulation, and discloses a method for simulating fracture-vug type reservoir body electric logging response. The method includes establishing an equivalent fracture-vug type reservoir body stratum model according to regional geological data, determining basic parameters of the equivalent fracture-vug type reservoir body stratum model; establishing finite element functions according to the DC logging response of the equivalent fracture-vug type reservoir body stratum model; carrying out grid discretion and resistivity assignment on the equivalent fracture-vug type reservoir body stratum model based on finite element theory; and assembling and solving finite element conductance array and obtaining depth lateral logging value. The method solves the problem of trans-scale grid dissection of a fracture-vug type reservoir body, effectively carves the boundary of the fracture-vug type reservoir body, scientifically simulates the values of fracture-vug type reservoir body electric logging, and provides theoretical basis for identifying and evaluating electric logging of carbonatite and volcanic fracture-vug type reservoir body according to electric logging data.

Description

technical field [0001] The invention belongs to the field of electrical logging numerical simulation, and relates to a method for simulating the electrical logging response of a fracture-cavity type reservoir. Background technique [0002] Carbonate, volcanic and other oil and gas reservoirs are widely developed in fractured-cavity reservoirs. Because the reservoir has the characteristics of strong heterogeneity, obvious anisotropy, unequal development scale and uneven distribution of fractures and caves, and large changes in the type and degree of filling, the electrical logging response of fractured-vug reservoirs is complex, and it is easy to cause Ambiguity and ambiguity of logging evaluation results. [0003] At present, there are very few studies on electrical logging numerical simulation of fractured-cavity reservoirs at home and abroad. Faivre et al. conducted a model study of single fracture and parallel plate fractures for fractured formations, and solved the num...

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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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