Study and Field Application of Area-Apparent Porosity of Coal Seam Disturbance Based on Resistivity Imaging Technology
Year: 2025
Type: article
Abstract: Effective evaluation of coal and rock condition and disturbance stress changes is an important way to prevent deep geological hazards. Electrical resistivity imaging (ERI)technology provides an effective solution for geotransparency and stability monitoring of underground roadways. In this paper, we use the finite element method (FEM) to simulate the factors affecting the resistivity of the representative elementary volume (REV) and obtain the coupled equations for the resistivity of the REV using the differential effective medium approximation method (DEMA). On this basis, an inversion method for the apparent porosity of coal seam was proposed and succeeded in accurately evaluating the disturbed changes in coal seam. The main conclusions are as follows: the REV resistivity is affected by the combined effect of resistivity and porosity. The resistivity ratio acts as an obstruction or linkage to the electric field transfer. Porosity further increases the degree of obstruction or linkage, and the degree of this change varies linearly with porosity. The porosity-resistivity change path is the basic path that characterizes the resistivity of REV. A coupled equation for REV resistivity is established based on the DEMA, which quantitatively characterizes the effect of the porosity and resistivity ratio to coal together on resistivity. Based on this quantitative relationship, the calculation equation of apparent porosity of coal rock body is derived, and the inversion method of apparent porosity based on apparent resistivity data is proposed. The practical results show that the apparent porosity varies significantly in the disturbed area and less in the undisturbed area. This study helps to improve the quantitative analysis of ERI technology for deep subsurface exploration and geotransparency of deep coal rock state.
Authors: Qiang Liu, Liming Qiu, Dazhao Song, Longgang Zhao, Yong Liu, Hairui Liu, Yujie Peng, Qian Sun, Yingjie Zhao, Yi Zhu
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W4416772729