Exploring coal seam wind oxidation zone based on transient electromagnetic method

Abstract

The development of coal seam wind oxidation zone has a huge impact on the production organization and safe mining of coal mines. This paper focuses on the technical difficulties in delineating the coal seam wind oxidation zone in the eastern uplift zone of Junggar Coalfield, and studies the feasibility of using transient electromagnetic method to explore the coal seam wind oxidation zone. Firstly, the electrical resistivity logging curves of normal strata and coal seam wind oxidation areas in the research area were analyzed, and the differences in electrical properties between normal areas and coal seam wind oxidation areas were summarized. A geoelectric model of coal seam wind oxidation areas was constructed based on the electrical resistivity logging curves; then, MAXWELL software was used to numerically simulate the transient electromagnetic response of the theoretical model. It was found that the resistivity cross-section of the transient electromagnetic inversion in the coal seam wind oxidation zone exhibited abnormal characteristics of shallow low resistance layer thickening and reduced low resistance anomaly amplitude, which can be used to delineate the distribution range of the coal seam wind oxidation zone; finally, based on numerical simulation, on-site experiments were conducted in the Chuancao Gedan Coal Mine. Combined with drilling conditions, the experimental data were analyzed from the perspectives of transient electromagnetic inversion resistivity cross-section and plane. The results showed that the transient electromagnetic method is feasible for detecting and dividing wind oxidation zones.

Keywords

• transient electromagnetic method
• coal seam wind oxidation zone
• resistivity cross-section
• junggar coalfield
• roof water disaster