Method for reconstructing digital rock core and pore network model based on random fractal theory

Abstract

The invention discloses a method for reconstructing a digital rock core and pore network model based on a random fractal theory. The method comprises the following steps of based on the multiple fractal features of a porous medium, performing fractal representing on a capillary pressure curve obtained by the conventional mercury intrusion method, inferring fractal expressions of random distribution density function, average value and variance by a random distribution theory, and combining the random theory and the multiple fractal theory to construct a digital rock core, so as to rapidly construct a three-dimensional micro-network model. The method has the advantages that the cost is low and is reduced; the capillary pressure curve is measured by the mercury intrusion method, the full-section rock core is used in experiment, and a micro-pore structure is fully displayed. According to the method, the computing method is simple and convenient, and the advanced method is adopted; the micro-pore structure of reservoir rock is complicated and irregular, and an extremely complicated system cannot be accurately described by the traditional classical theory, so after the method combines the multiple fractal theory and the random distribution theory, the micro-pore structure can be accurately represented, and the method is easily implemented by programming.

Description

technical field [0001] The invention relates to a method for constructing a three-dimensional quantitative description of the microscopic pore structure of a porous medium, in particular to a method for constructing a digital rock core based on a pore network model. Background technique [0002] In the past, the microscopic mechanism of fluid seepage in porous media was mostly studied qualitatively through experiments, and the research results mostly stayed on the macroscopic scale, so it was difficult to have a more in-depth and detailed understanding of the microscopic mechanism. In order to quantitatively describe the seepage problem on the microscopic scale, the first problem to be solved is to describe the microscopic pore structure finely. In recent years, scholars at home and abroad have carried out a lot of research work in this field. In conclusion, the research ideas are mainly in the following two categories: 1. Based on digital cores, the flow simulation is carri...

AI Technical Summary

Problems solved by technology

The technical requirements for core imaging are not only high, but also the obtained cores are thin slices, which are small in scale, costly for testing, and difficult to popularize and apply.

Numerical reconstruction method A variety of reconstruction methods developed so far rely on various statistical methods or simulate the formation process of the core to establish a digital core, the typical ones are Gaussian simulation method, simulated annealing method, process simulation method, multi-point simulation method, Multi-point statistical method and Markov stochastic reconstruction method, but the digital cores established based on these methods are isotropic and cannot quantitatively characterize complex pore systems

Images