Application of sand jet perforation technology in in-situ leaching well building

During the study process for the drilling technology in multilayer ore body mining in Mengqiguer deposit, in order to build the hydraulic connection accurately between the ore bearing aquifer and the cemented leaching well, and recover the aquifer permeability, the sand jet perforation technology was introduced, which uses high-pressure water with sand to cut the casing and surrounding stratum by jetting tool. Before the underground application, an ground experiment had been conducted using a well model. On the basis of mastering the damage-degree of PVC casing and optimum technical parameter of sand ratio, field sand jet perforation applied experiment was carried out in six wells. Results show that the high-pressure water with sand can cut the casing is stratum effectively, and the PVC casing was not destroyed. The mud infiltrating into surrounding aquifer can also be cleared by the high-pressure water, and hence the aquifer permeability is enhanced. (authors)