Quantitative analysis of microscopic structure and gas seepage characteristics of low-rank coal based on CT three-dimensional reconstruction of CT images and fractal theory

Effect of ionic liquid treatment on pore structure and fractal characteristics of low rank coal

Deformation and water transport behaviors study of heterogenous coal using CT-based 3D simulation

Experimental investigation on coal pore and fracture characteristics based on fractal theory

Imaged based fractal characterization of micro-fracture structure in coal

Characterization of pore-fracture networks and their evolution at various measurement scales in coal samples using X-ray μCT and a fractal method

Permeability evolution of deep coal samples subjected to energy-based damage variable

NMRI online observation of coal fracture and pore structure evolution under confining pressure and axial compressive loads: A novel approach

Permeability in porous media has an important role in many engineering applications, which depends mainly on the pore size, distribution, and connectivity of porous media. As the pore structure distribution of coal has a multi-scale fractal dimension characteristic, this study aimed to propose a multi-scale fractal dimension characteristics units model (MFU) to describe the pore structure distribution by analyzing the multi-scale fractal dimension characteristics of coal pore media. Then, a multi-scale fractal permeability model was established based on MFU. The pore structure distribution was obtained by mercury injection porosimetry (MIP) and nuclear magnetic resonance (NMR) experiments. Based on MIP and NMR experimental data, the permeability contribution of different pore diameters were calculated. The results show that the permeability contribution of the micropore was minimal and can be ignored. The permeability contribution of mesopores was about 1–5%, and the permeability contribution of macropores was about 95–99%, which plays a decisive role in the seepage process. The calculated results, based on multi-scale fractal permeability model and the experimental permeability data, are in the same order of magnitude. The permeability prediction based on proposed model is better than classical single fractal permeability model.

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J.C. Zhong

Papers

Characterization of pore-fracture networks and their evolution at various measurement scales in coal samples using X-ray μCT and a fractal method

Permeability evolution of deep coal samples subjected to energy-based damage variable

NMRI online observation of coal fracture and pore structure evolution under confining pressure and axial compressive loads: A novel approach

A Multi-Scale Fractal Approach for Coal Permeability Estimation via MIP and NMR Methods