Construction Method of Porous Media Equivalent Simplified Model for Numerical Simulation of Tight Reservoir

Abstract

The present invention relates to a porous medium equivalent simplified model construction method for numerical simulation of tight reservoirs. It is based on the idea of ​​reducing the pore space of reservoirs through the synergistic effect of rock mineral particle compaction and cementation, and establishes a three-dimensional accumulation of dense porous medium sandstone particles. Simplify the geometric shape model; firstly, establish the tangent micro-elements of the sandstone particles with equal diameters; use the Rayleigh distribution function to characterize the sandstone particle size distribution, and establish the shape of large sphere accumulation combined with small sphere filling with the particle size obeying the Rayleigh distribution. The diameter and longitudinal random staggered arrangement constitutes a three-dimensional sphere packing model; the synergy coefficient is introduced to characterize the compaction of dense porous media and the influence of cement cementation on the pore shape; combined with the lattice Boltzmann simulation method to fit the synergy coefficient, the compactness Construction of 3D simplified geometric model of reservoir pore structure. The invention can reflect the differential characterization and alternate distribution of the geological origin of tight reservoirs and pore throats, and realize the porosity and seepage capacity.

Description

Technical field: [0001] The invention relates to a method for modeling and simplifying the real physical structure of a dense porous medium in the numerical simulation technology of a dense reservoir, and specifically relates to a method for constructing an equivalent simplified model of a porous medium for numerical simulation of a dense reservoir. Background technique: [0002] Tight oil and gas reservoirs have the characteristics of low porosity and low permeability. Conventional micro-tube flow experiments cannot meet the requirements of the distribution range of pore throats in tight gas reservoirs. It needs to be realized by means of microscopic numerical simulation, so as to determine the law of fluid flow in tight porous media. and influencing factors. The most typical characteristics of tight sandstone reservoirs are that the sandstone particles are poorly sorted and the particles of different sizes fill each other, resulting in the tight accumulation of mineral par...

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Problems solved by technology

[0007] The purpose of the present invention is to provide a porous medium equivalent simplified model construction method for tight reservoir numerical simulation, this porous medium equivalent simplified model construction method for tight reservoir numerical simulation can reflect the tight reservoir geological origin and pores The differential characterization and alternate distribution of throats can solve the problem that existing methods cannot truly reflect the real flow resistance of tight reservoir fluids

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