Advanced drilling detection and multi-information identification of water-conducting channel of coal floor

The coal floor develops various water-conducting channels, which seriously threaten the safe production of mines. In order to establish a more scientific multi-information identification technology system for the water-conducting channels in the coal floor, and prevent floor water inrush. Firstly, the principles of reasonable trajectory, reasonable target layer and exploration area maximization are proposed based on the characteristics of the water-conducting channels and the advantages of the ground directional drilling area exploration technology. Diversified types, unclear locations, and significant water inrush hazards are the characteristics of water-conducting channels. Secondly, the summary analysis is conducted on the exploration process of water diversion channels in areas such as HuaiBei Mining Area, Huainan Mining Area, Xingtai Mining Area, and Huanghebei Coal Field. When revealing the water-conducting channels, there are significant differences in visual indicators such as rock debris, drilling time, drilling fluid leakage, and confirmatory indicators such as permeability and grouting parameters compared to revealing normal formations. Therefore, the identification indicators of multi-information during the drilling process are divided into two types: qualitative and quantitative. Based on the variation amplitude of two qualitative indicators, rock debris and drilling time, when encountering water-conducting channels, it gives corresponding standard curves, and determines the classification system for water-conducting channel types. Subsequently, a comprehensive analysis is conducted on the changes in the two quantitative indicators of drilling fluid leakage and permeability when encountering water-conducting channels. 30 m³/h of drilling fluid leakage and 10 Lu of permeability are proposed as the classification criteria for conductivity. Based on this, a dual factor comprehensive classification system for water-conducting channels conductivity is established, and the conductivity is divided into four levels. Finally, taking a typical mine in the North China coalfield as a case study, the principle of exploration is adopted to explore the water-conducting channels. The multi-information identification technology is applied to successfully identify four faults, two karst fracture zones and a collapse in the detection area, and determines conductivity levels of water-conducting channels. The research results have guiding effect and important significance for improving the identification and control of water-conducting channels.