Unsteady gas-water two-phase seepage simulation method for dual-medium gas reservoir based on pore cracks

Abstract

The invention relates to an unsteady gas-water two-phase seepage simulation method for a dual-medium gas reservoir based on pore cracks. The method comprises the following steps: acquiring a T2 spectrum of a rock core, and converting to obtain a pore throat radius distribution frequency and a pore throat distribution function; obtaining the core pore throat length and coordination number for establishing a disordered pore network model through micro CT scanning, and adding the number of cracks; establishing a pore crack type double-medium model; introducing an unsteady seepage theory , and combining a dynamic network simulation algorithm and the unsteady seepage theory to simulate the gas-water two-phase seepage and pressure propagation process of the fluid dual-medium gas reservoir. According to the method, unsteady gas-water two-phase flow simulation is carried out on the basis of a pore and crack dual-medium model, and the pore-level gas-water two-phase flow process can be describedmore accurately through dynamic network simulation considering the compressibility of fluid in the traditional gas-water two-phase seepage process; pressure distribution of the gas-water two-phase inthe pore and crack dual-medium in pressure wave propagation can be analyzed, and flow rules of fluid in pores and cracks can be researched.

Description

technical field [0001] The invention relates to the field of oil and gas field development, in particular to a method for simulating unsteady gas-water two-phase seepage in dual-media gas reservoirs based on pores and fractures. Background technique [0002] my country's natural gas reserves are large and widely used, and it is one of the important clean energy sources. After years of research, the development methods of conventional gas reservoirs have become mature. Most researchers use a single pore sandstone structure network model for gas reservoir numerical simulation research, and this type of technology has become increasingly mature, but considering low permeability-dual media There are relatively few studies on the mechanism of unsteady seepage in gas reservoirs. [0003] At present, many researchers at home and abroad usually use the continuum theory to study multiphase seepage in porous media. However, due to the discontinuity of viscous force and capillary forc...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a simulation method for unsteady-state gas-water two-phase seepage based on pore-fracture dual-media gas reservoirs, which solves the current problems of unsteady-state seepage simulation research on pore-fracture dual-media lack of

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