Drilling technology for complex formation in the Ergadiji lead-zinc mine area in Sichuan

Abstract:

The Erxiadiji lead-zinc mining area in Sichuan is located at the combination of the northern segment of the north-south Ganluo-Xiaojiang fault （called the Malaha fault in this area） and the Malaha anticline. The regional geological conditions are complex， with broken rock formations and developed fissures， and there are drilling problems such as borehole collapse， leakage， diameter reduction， and falling stones. In order to avoid downhole incidents， shorten the drilling period and reduce operation risks， research work on drilling technology has been carried out in the mining area. Taking drilling problems in ZK4522， ZK4737， ZK7545 holes as examples， the causes for frequent drilling incidents are analyzed， improvement measures are put forward， and the drilling structure design suitable for the mining area is summarized. The formulation of flushing fluid used for different strata is expounded， and technical control measures are proposed for cement slurry wall protection and casing wall protection with good results achieved in the mining area. A set of drilling plans have been developed with practical reference value， which provides technical support measures and experience for future drilling in the mining area， and also some reference for other similar drilling works.