Method for characterizing three-dimensional pore network structure parameters of coal rock

Abstract

A method for characterizing the pore network structure of a coal rock comprises the following steps: obtaining three-dimensional data of a coal rock core pore structure by a CT technology, establishing a three-dimensional digital rock core, and establishing a three-dimensional pore network by using a central axis algorithm; simplifying the model data of the pore network, simplifying pores into nodes, simplifying pore passages into edges, marking the pores, and deriving pore communication information; and using a complex network to characterize the basic information of the network, comprising the total number of the nodes, the total number of the edges, node distribution, the average degree of the nodes, the average path length of the network, the network clustering coefficient, the networkmedia, the network density and the network robustness. Compared with traditional coal rock pore structure analysis methods, the method in the invention increases network property analysis, can analyze the seepage law of different pore network communication structures having the same porosity to achieve the purpose of improving the existing gas recovery rate at the microscopic level, and adopts acomplex network theory to quantitatively characterize the pore structure network parameters of the coal rock in order to accurately and comprehensively characterize the pore network communication property of the coal rock.

Description

technical field [0001] The invention belongs to the field of mine gas drainage, and in particular relates to a quantitative characterization method for coal rock pore network structure parameters. Background technique [0002] The pore shape of gas-bearing coal rock mass is complex and distributed across scales, and its structural characteristics are one of the main factors affecting the gas storage and migration mechanism. Quantitative characterization of the shape, connectivity, and seepage path selection of three-dimensional pores in coal rocks is of great significance for studying the mechanism of gas accumulation in reservoirs, revealing the mechanism of gas migration and improving oil recovery. [0003] To this end, Professor Ghous from the University of New South Wales in Australia used high-precision CT scanning and focused ion beam scanning to obtain the rock morphological structure of macropores and micropores respectively, established a network model by fusing por...

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Problems solved by technology

[0004] The above-mentioned characterization methods surrounding the pore connectivity structure of coal and rock mass are of great significance to the characterization of rock pore structure, but they are all one-sided and cannot truly reflect the pore structure of coal and rock mass. The topological characteristics of the network

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