Method for predicting fractured reservoir stress evolution based on fractured continuum model

Abstract

The invention discloses a method for predicting fractured reservoir stress evolution based on a fractured continuum model, and the method comprises the following steps: building a simulated physical model based on geological parameters, construction parameters, boundary conditions and initial conditions, and determining basic parameters; establishing a natural fracture random distribution model, and calculating permeability of grids corresponding to natural fractures; establishing a stress balance equation and a continuity equation based on elastic mechanics, a finite element method and a seepage theory, and substituting the permeability into the stress balance equation and the continuity equation; and establishing a non-planar hydraulic fracture, a discrete stress balance equation and a continuous seepage equation based on a finite element method to obtain a discrete form of the discrete equation and the continuous equation, and calculating the distribution state of reservoir stress corresponding to each age limit. According to the method, stress prediction can be carried out in the later period of fractured reservoir development, a reliable guiding effect is provided for repeatedfracturing design and infilled well design, and development of oil and gas development theoretical research can be promoted.

Description

technical field

[0001] The invention relates to the technical field of stress evolution in the later stage of fractured reservoir development, in particular to a method for predicting the stress evolution of fractured reservoirs based on a fracture continuum model. Background technique

[0002] In oil and gas production, with the deepening of development, the pore pressure in the reservoir gradually decreases. At this time, due to the pore pressure gradient generated by the heterogeneity of reservoir pore pressure distribution, the original reservoir stress distribution is induced to change. In conventional reservoir research, the reservoir is generally considered as a porous media elastic body. When studying the coupling law of fluid flow and geological stress in the poroelastic model, it is generally believed that there are only three main directions of fluid flow. But the reason for fluid flow is due to the presence of a pressure gradient. For reservoirs like shale whe...

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