Energy and Minerals Australia are currently developing Western Australia’s largest independently owned uranium resource, the Mulga Rock deposits with production targeted for 2014. Located 250km East of Kalgoorlie and 100km north of the trans-national rail line, the location is very remote, the climate is arid, and the terrain is harsh, with sand dunes and sparse vegetation.
Bostech Drilling Australia have conducted several drilling campaigns on this deposit which is characterized by extremely challenging geology from a drilling perspective. Typically the lithology consists of unconsolidated sands from surface, followed by bands of calcrete. This is followed by a sequence of clay followed by lignite. The challenge here is that the Lignite has a very low specific gravity such that when being drilled, a fine balance must be maintained between bit face pressure and the hydrostatic formation pressure to successfully recover the representative in situ sample.
The degree of difficulty that this formation presents has been such that virtually every type of Drilling technique has been tried in the past. This includes non –Bostech Air core, Diamond Coring, R.C. Hammer, Rotary Mud and Sonic which have all been attempted but in every case have failed to produce satisfactory results.
Only Bostech with our dedicated field crews using our unique air coring technology have been able to consistently deliver high quality samples at a sustainable level of production and cost.
Bostech Drilling Australia recently completed a 20,000 m drilling program during the first quarter of 2012 which was focused on expanding the low cost ISR amenable sandstone uranium resources in the deposit. Despite the most challenging drilling conditions imaginable, including negotiating through ultra abrasive unconsolidated formations creating extreme wear on all the down-hole components, in particular inner tubes and bits, the drilling campaign was completed on time and within budget.