Project Description
In 2025, Foundex was retained by Quinsam Coal Corporation to drill and install a large diameter injection well. Foundex mobilized a Foremost DR 24 drill and reverse circulation tooling to the mine. The injection well design required a 467 mm diameter surface casing to be drilled and seated into the top of bedrock. The drill string was then advanced open hole using a 432 mm diameter bit into the target formation associated with underground mine workings.
Once target depth was reached and the underground shaft was intercepted at 72 metres below ground surface, a 305 mm diameter steel liner with a perforated lead was fabricated in sections, welded, and lowered into the hole, extending to surface. A custom K packer and shale trap assembly was attached to the 305 mm casing and set at 30 metres below grade. Once the liner assembly was set on bottom, a layer of bentonite was placed on top of the shale trap, followed by a small initial grout lift that was allowed to cure. Subsequent grout lifts were placed in stages from the shale trap seal to surface, sealing the annular space between the bedrock and the liner.
An injection well valve head assembly was then welded and flanged to the top of the 457 mm diameter surface casing, providing the client with controlled access for future reinjection operations.
