Abstract

A method and apparatus for in-situ leach mining which utilizes multiple dhole branch wells whipstocked off a single main generally vertical well. Initially the vertical well is drilled into the earth so that it may intersect the ore zone of material to be recovered. The vertical well may be cased and cemented after drilling. Thereafter from this same well a plurality of branch wells are whipstocked or drilled which intersect the vertical well at an angle from about 2 degrees to 60 degrees. These branch wells extend into the ore zone. A submersible pump and drop pipe are placed in the main well and at some point below the intersection of the main well with the branch wells a packer is placed around the drop pipe. The drop pipe carries solutions to the surface from the pump. Leaching solutions are forced or injected in the main well in the volume between the exterior surface of the drop pipe and well hole or casing so that upon encountering the branch wells and packer their solutions are forced into the branches and out into the ore body. After exiting near the opened ends (or well screens) of the branch wells into the ore zone, the leaching solution dissolves the mineral values and the solution flow with its entrapped minerals is forced by the action of the pump through the ore zone towards the vertical well, where the solution is pumped up to the surface, via the inner drop pipe.