Progress positive for Pike River Recovery
17 January 2019
Several Pike River Recovery Agency mining staff have this week been trained in using the new 950 kg venturi destined for a Pike River Mine borehole on the Paparoa Ranges.
The venturi has been fabricated at Gray Brothers Engineering in Greymouth and once installed will extract nitrogen and methane from the Pike River Mine drift, as part of the re-entry and recovery project.
In late February, the venturi itself will be flown by helicopter to the borehole site in three main parts and re-assembled on site.
Australian company Crown Technology are providing the training at Gray Brothers Engineering in Greymouth, covering reassembly, installation and how the venturi will be used on site.
Purging tests carried out before Christmas reduced methane levels in the first 180m of the Pike River Mine drift from 96% to around 2%, and oxygen levels dropped to less than 1%.
“It happened quicker than we thought, so it was great to have these early tests. We’re restarting purging tests today – the more information we have on the speed the nitrogen pushes up the mine to displace the methane and maintain a stable environment, the better it is for our planning towards re-entry,” Chief Operating Officer Dinghy Pattinson says.
Purging will continue for 12 hours a day, seven days a week while the data is gathered about gas levels in the mine.
The installation of the portal emergency doors is continuing. The actual doors are now in place and the winching system has been attached to the outside of the portal. Further work will continue to seal the area around the doors in the next few weeks.
Miners continue to lay the rest of the 9km of pipelines above the portal, which will take nitrogen up to boreholes in the mine workings and drift.
“They’re more than a third of the way through, but ahead of schedule because the weather has been great. Some of the more difficult terrain is to come though,” Dinghy says.
The drilling programme commenced this week, with the first of three new boreholes that will be used for gas monitoring drilled through into the drift access tunnel about 1400m from the portal yesterday. Two further boreholes, one either side of the roof fall 2.3km into the drift, will commence shortly.