Mechanical simulation method for describing deformation and migration of oil displacement agent in porous medium

Abstract

The invention belongs to the technical field of oilfield development and relates to a mechanical simulation method for describing the deformation and migration of an oil displacement agent in a porousmedium. The method comprises the following steps that: step 1, the boundaries of viscoelastic particles are dispersed into a series of virtual particles; 2, acting force borne by each boundary virtual particle is calculated; 3, the speed and displacement of each virtual particle after time delta t are calculated; and 4, a polygon defined by connecting the virtual particles after the time delta tapproximately represents the position and shape information of the viscoelastic particles at the current moment. According to the method, the accurate description of the deformation and migration of the viscoelastic particle oil displacement agent in the porous medium is achieved; a heterogeneous chemical oil displacement mechanism research method is improved; and a theoretical basis and an application means are provided for the deep understanding of the oil displacement mechanism of the viscoelastic particle oil displacement agent, the research and development of the viscoelastic particle oildisplacement agent and the design of a heterogeneous chemical oil displacement system.

Description

technical field [0001] The invention relates to the technical field of oil field development, in particular to a mechanical simulation method for describing the deformation and migration of oil displacement agents in porous media. Background technique [0002] The main oilfields in the Shengli Oilfield have gradually entered a period of high water cut and ultra-high water cut. It is difficult to stabilize production, and the contradictions in development are becoming more and more prominent. It is more difficult and costly to explore new reserves. Therefore, the recovery rate of proven and developed reserves is further increased has become a very urgent task. Viscoelastic granular oil displacement agent is a new type of granular oil displacement agent with a unique molecular structure of "partially cross-linked and partially branched". , liquid flow diversion, balanced displacement and high-efficiency oil washing provide an effective way for high water cut, high recovery an...

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Problems solved by technology

[0004] Due to the elasticity of the viscoelastic granular oil displacement agent, during the core displacement test, its injection pressure fluctuated in a sawtooth shape, showing the migration characteristics of "temporary plugging-deformation-passing". Viscoelasticity can also be observed in microscopic visualization tests. The deformation of the granular oil displacement agent at the pore throat, however, due to the limitations of equipment and research methods, it is impossible to obtain the accurate critical conditions for the deformation of the viscoelastic granular oil displacement agent at the pore throat, so that the seepage in porous media Due to the limited understanding of the law and mechanism of oil displacement, the simulation study of viscoelastic granular oil displacement agents is essential

[0005] However, the existing classical seepage theory cannot accurately simulate the flow and deformation of each deformable viscoelastic particle oil displacement agent in porous media. Therefore, it is necessary to establish a simulation method based on deformable viscoelastic particle oil displacement agent, for Provide research methods for clarifying the seepage law of viscoelastic granular oil displacement agents in porous media and deepening the understanding of heterogeneous chemical flooding mechanism

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