Technical Overview

Coal mine power disaster accidents have a process of incubation, development, and occurrence. By innovating theoretical methods and changing the ways of excitation and reception, different scales and near-field coupling excitation can be achieved, and full space, multi parameter tensor measurement can be carried out; Mastering the spatiotemporal evolution characteristics of the geoelectric anomalies that cause coal mine power disasters, comprehensively and objectively studying the stress transfer, structural evolution, and fluid motion laws of the mining rock mass at different spatial and temporal scales, is necessary to timely detect the precursor information of the disaster before the reversible stage of the coal rock mass without sub instability occurs before the stress peak arrives, and to win time for taking measures to proactively eliminate potential production safety threats. Tensor resistivity measurement is an important method for mastering and understanding the characteristics of electrical anisotropy, and coal mines have unique advantages in conducting tensor resistivity measurement underground. The deformation, failure, and fluid migration of mining rock masses will inevitably cause the regular spatiotemporal evolution of the electrical anisotropy characteristics of coal bearing strata. By dynamically measuring the tensor resistivity of coal and rock masses in real-time, local and microscopic electrical anisotropy characteristics caused by mining activities and fluid migration can be identified and discovered. Timely capture the precursor information of coal mine dynamic disasters before the peak stress is reached; Taking preventive measures during the reversible stage before stress release can prevent major power disasters in coal mines from occurring at the source.

System Characteristics

• Macroscopic electrical anisotropy can be used for directional detection, thereby detecting the interweaving of macroscopic structural anisotropy of layered media and microscopic anisotropy caused by tunnel cavities and geological structures.

• The anisotropy coefficient of water and gas saturation in fractures has a significant impact on the transverse and longitudinal resistivity of coal seams, allowing for the detection of water content.

• Real time understanding of the spatiotemporal evolution characteristics of geoelectric anomalies caused by coal mine power disasters, comprehensively and objectively studying the stress transfer, structural evolution, and fluid migration laws of mining rock masses at different spatial and temporal scales, timely discovering the precursor information of disasters, and winning time for taking measures to proactively eliminate potential production safety threats.

• Based on 5G technology, achieve real-time dynamic monitoring of full space, full tensor, and multi parameter time-frequency electromagnetic fields.

Function Introduction

• Real time monitoring of water and gas enrichment status in coal seam fractures;

• Structural exploration and positioning of coal seam media, tunnel cavities, and geological structures;

• Real time monitoring of karst under the floor;

• Set up fixed electromagnetic emission base stations on the ground and movable near-field emission sources underground, and achieve real-time dynamic monitoring of full space, full tensor, and multi parameter time-frequency electromagnetic through underground electromagnetic sensor networks.

Application Cases

A certain mine in Huaibei used tensor resistivity method to explore hidden collapse columns, small structures, sandstone rich water areas at the top and bottom of the mining face, karst development areas or fault zones, and other hidden water conducting structures, and to identify the goaf area and water accumulation range of the upper coal group or the same coal seam old kiln.

Measurement point layout: According to the position of the electrode layout, the advanced resistivity detection method is divided into three working modes: the "U" - shaped centerline of the roadway side, the centerline of the roadway floor, and the centerline of the borehole: