Shale gas reservoir fluid-solid coupling multi-scale numerical simulation method

Abstract

The invention discloses a shale gas reservoir fluid-solid coupling multi-scale numerical simulation method. The method comprises the following steps: obtaining spatial distribution and physical property parameters of organic matters and inorganic matters, constructing a physical model of a micro-scale shale matrix, solving a micro-scale seepage auxiliary equation and a mechanical auxiliary equation, and calculating equivalent seepage and mechanical parameters of the shale matrix core scale; acquiring a natural fracture distribution situation, constructing a rock core scale physical model containing a shale matrix and natural fractures, solving a seepage auxiliary equation and a mechanical auxiliary equation of the rock core scale, and calculating equivalent seepage and mechanical parameters of a shale gas reservoir macro-scale; on the basis, simulating a hydraulic fracture by adopting an embedded discrete fracture model, and establishing a shale gas reservoir macroscopic fluid-solid coupling model; and finally, based on the structured grid, solving the shale gas reservoir fluid-solid coupling model by adopting a mixed numerical discretization method combining simulated finite difference and extended finite elements so as to realize shale gas reservoir fluid-solid coupling numerical simulation with high simulation precision and small calculated amount.

Description

technical field [0001] The invention relates to the field of reservoir numerical simulation, in particular to a multi-scale numerical simulation method for fluid-solid coupling of shale gas reservoirs Background technique [0002] Shale gas resources are widely distributed and have large reserves, but the permeability of the reservoir matrix is ​​extremely low, and hydraulic fracturing is usually required for commercial exploitation. After fracturing, shale gas reservoirs develop a large number of fractures and are in a complex in-situ stress field In the joint action of the seepage field and the seepage field, the fluid-solid coupling effect is significant. At the same time, shale gas reservoirs contain multi-scale storage and seepage spaces: micro-scale organic and inorganic pores, core-scale natural fractures, and macro-scale artificial fractures. However, the current macroscopic numerical simulation methods for shale gas reservoirs are difficult to accurately capture th...

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Problems solved by technology

However, the current macroscopic numerical simulation methods for shale gas reservoirs are difficult to accurately capture the mechanical and seepage characteristics of micro-scale organic matter and inorganic matter and core-scale natural fractures, and based on lattice Boltzmann, directly solving N-S equations and discrete elements, etc. The calculation area of ​​the micro-scale numerical simulation method of the method is too small to be directly used for large-scale actu

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