Our clients are able to call upon DDH1 as the premier provider of bespoke solutions to complex technical problems. Our breadth of experience allows us to provide highly accurate directional drilling used to drill mine service holes designed to break into existing mine workings at very specific points.
As a first step to most projects, DDH1 directionally drill pilot holes which are steered to the target by using advanced gyro down hole surveying and oilfield directional drilling equipment. These holes are used to deliver paste backfill directly from a surface paste plant to the underground area, to lower large high voltage electrical cables directly from surface to deep underground, and to pump ground water from underground workings.
Once the directionally drilled pilot core hole has broken through, the holes are then enlarged to accept a designed casing size. Enlarging the hole diameter is accomplished by using down hole hammers and significant expertise is required to ensure that holes are not blocked up or lost. We generally find that if holes are into open mine workings then spoil from the opening is allowed to drop into workings which minimizes down hole compressed air requirements.
As an example of our technical expertise, DDH1 drilled an electrical drop hole for a Western Australian client which involved a pilot hole to 1,446m. This hole was opened to 12.25 inches, cased with a 9 inch diameter 100 ton oilfield casing string and grouted back to surface with 60 cubic meters of grout. This hole is the deepest single pass cable drop hole in the Southern hemisphere and is now powering the deeper mine extensions.