WA gold mine delivers core drill hole record

DDH1's Murray Pollock and Matt Thurston.

DDH1 Drilling has drilled the deepest mineral core hole in Australian history at Northern Star Resources’ Jundee gold mine in Western Australia.

The drill hole depth reached an incredible 3217m at the mine near Wiluna by February 28 this year.

Deploying Sandvik NHD heavy duty rods rated to 3000m, and using a 2500m-rated Sandvik DE880 rig, the drill hole extended 200m beyond the previous core drill record achieved at the Kalgoorlie Super Pit in 2015.

The drill was originally planned to stop at 3100m, but some intriguing indications made Northern Star push on. This was beyond the rated capacity of the NHD drill rod and DE880 rigs rated capacity, but obviously not beyond their safe technical limits.

DDH1 chief executive Murray Pollock described Sandvik’s 3000m rating for the NHD as conservative.

“It’s a tough, very reliable drill rod which is obviously capable of more,” he said.

Pollock said if it wasn’t for Northern Star calling a halt, they could have continued drilling past this record depth, which had a true vertical depth (TVD) of 2625.1m. He added that pushing the drill boundaries is by necessity a growing trend.

Since most of the more accessible deposits, certainly those with surface expression, have already been discovered, exploration companies are using sophisticated geophysical methods to highlight deep structures. These can only be examined by drilling extremely deep holes.

DDH1 is, among other projects, currently drilling a 2950m deep hole at St Barbara’s Gwalia gold mine, north of Kalgoorlie.

The company is also engaged in a significant number of other exploration drilling operations across WA, the Northern Territory and the east coast.

These are managed by DDH1 co-founder Matt Thurston and a team of operations managers, all of whom are experienced deep hole directional drillers.

Pollock, a big fan of Sandvik drill rigs and equipment, said that when commencing drilling operations in 2006, he and Thurston chose a Sandvik DE880 as the company’s first rig.

“That decision has been vindicated many times. DDH1 presently operates a total of 37 Sandvik rigs, including the Sandvik UDR5000, UDR3000, UDR650, DE710, DE840 and DE880,” Pollock said.

“The company has 20 DE880s, the particular rig used in the Jundee record-breaking drilling operations.”

Most of all, Pollock and Thurston like the high driller acceptance of Sandvik, a factor which is critically important to DDH1.

“Sandvik’s the industry standard,” Pollock said. “It’s the brand many of our client companies specifically ask for, with good reason. It’s a great feeling to know you can have complete confidence in your rigs, drill rods and other drilling equipment.”

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