Dual-porosity dual-permeability model and dynamic prediction method for shale gas reservoir considering gas-water two-phase flow

Abstract

The invention discloses a dual-porosity dual-permeability model and dynamic prediction method for a shale gas reservoir considering gas-water two-phase flow. Aiming at the flow of gas in a formation from an entire matrix system to natural fractures, gas-water two-phase flow exists in the matrix system and the fracture system, and the condition that the matrix permeability is corrected by the influence of an adsorbed water layer in inorganic nano-scale pores is considered, the proportion of organic matter and clay minerals and the respective adsorption and desorption constants thereof are introduced to derive a shale gas reservoir gas-water two-phase flow dual-porosity dual-permeability model; and an IMPES method and Matlab mathematical software are adopted to program and solve the two-phase, three-dimensional, dual-porosity and dual-permeability model of multistage fractured horizontal wells in the shale gas reservoir, and the dynamic changes of production pressure are accurately predicted. The invention aims to solve the technical problem that shale gas reservoir gas-water two-phase dual-medium models in the prior art cannot accurately and dynamically predict the production pressure.

Description

technical field [0001] The invention relates to the technical field of shale gas development, in particular to a method for constructing a dual-porosity and dual-permeability model of a shale gas reservoir based on gas-water two-phase flow and a pressure dynamic prediction method. Background technique [0002] Most of the existing shale gas technology development focuses on the occurrence mechanism, rock characteristics and reserve potential of shale gas reservoirs. For the unique seepage mechanism, flow model, adsorption and desorption theory, gas-water two-phase flow problems and development of shale gas reservoirs Dynamic analysis and so on are still in the stage of hard research. In particular, gas-water two-phase flow will occur after fracturing in shale gas reservoirs. In order to accurately simulate and predict the production performance of shale gas wells, it is necessary to further study the complex seepage problems in the development process of shale gas reservoirs...

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Problems solved by technology

[0008] The main purpose of the present invention is to provide a method for constructing a dual-porosity and dual-permeability model and pressure dynamic prediction method for shale gas reservoirs based on gas-water two-phase flow, aiming at solving the problem of gas-water two-phase dual media in shale gas reservoirs in the prior art The technical problem that the model is not accurate enough for the dynamic prediction of output pressure

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