Comprehensive exploration of collaps column and three-dimensional construction technology of water plug based on directional horizontal drilling

The Ordovician limestone water inrush from floor caused by water-conducted collapse columns is the main water hazard threat in Tashan Mine of Tongmei Group. Water inrush from collapse columns once happened in the roadway excavation of 8228 working face. On the basis of comprehensive geophysical exploration above and below the well, the development boundary, the influence zone, the cementation of the fractured body and the distribution characteristics of the water flowing subsided column are found out by means of multi-layer and multi-branch surface directional horizontal drilling speed logging, drilling fluid leakage, cuttings logging and logging while drilling, and combined with data statistical analysis, so as to find out the development boundary of the water flowing subsided column and the distribution characteristics of the broken body filled in it, and to control the subsided column by Grouting. The results show that the length and short axis of the collapse column is 410 m, 200 m, and the broken area is mainly distributed in the right front of the driving head of the belt roadway near the water inrush roadway. The 3D geological modeling of the spatial structure and development characteristics of the collapse column is carried out by using Surpac software, and the main passageway area, fracture area and secondary fracture area are divided according to the crushing degree of the collapse column filling material. In view of the different zones of the collapse column broken body, the directional horizontal drilling control technology and separate zones of the grouting technology are used to construct the three-dimensional water-blocking plug. The safe mining of the working face is finally realized by the comprehensive treatment of cutting the source and reinforcing the water-flowing collapse column. The comprehensive exploration and treatment technology of directional horizontal drilling multi-branch collapse column provides a good reference for other similar projects.