Simulation method of low-permeability reservoir crude oil boundary layer

Abstract

The invention discloses a simulation method of a low-permeability reservoir crude oil boundary layer. The simulation method comprises the following steps: (1) building a digital rock core by a CT (Computed Tomography) scanning method; (2) dividing the built digital rock core by a Delauny triangular dividing algorithm to obtain a three-dimensional geometric model; and (3) carrying out numerical simulation of the divided three-dimensional description geometric model of the fluid by using a finite element method under the condition that the boundary layer influence is considered, namely solving an incompressible equation which is N-S equation of the fluid with micro flowing in holes to obtain a flowing rate field and a pressure distribution field of the fluid. According to the simulation method of the low-permeability reservoir crude oil boundary layer, comsol simulation is used; the manpower, material resources and time can be saved; a regular hole mesh model is used, the pore throat condition of the real rock core can be accurately simulated; the condition is more accordance with the actual condition; data results are processed, the thickness of the boundary layer can be accurately calculated and is closer to the thickness of the crude oil boundary layer of the real rock core.

Description

technical field [0001] The invention relates to a method for simulating the boundary layer of crude oil in a low-permeability reservoir, belonging to the technical field of simulation experiments for oil and gas development. Background technique [0002] The current research shows that most of the existing recovery mechanism studies are based on the macroscopic seepage theory, and the macroscopic seepage theory is based on the Darcy's seepage equation, so the seepage established on the basis of the Darcy's equation is used in the field of petroleum development. The equation can only describe the seepage characteristics of reservoir fluid macroscopically, but cannot give a more accurate description at the pore level. Especially in the study of low-permeability reservoirs, many scholars have shown through low-permeability core displacement experiments and development practices that oil and gas seepage in low-permeability reservoirs does not conform to Darcy's law. In order to...

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Problems solved by technology

The disadvantages of these two models are that the glass capillary model method is based on Darcy's law. For low-permeability and ultra-low-permeability reservoirs, the flow of fluid in the core pore throat does not conform to Darcy's law; Represents core pore throats and cannot simulate the interaction of fluid with the core surface when flowing in the pore throats

The rock capillary model calculates the average thickness of the boundary layer based on the poor quality of crude oil before and after core displacement. Due to the influence of experimental conditions, the error is large, and the model is too ideal

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