Ventilation shaft-filling phase of Pike River drift re-entry project is under way

Solid Energy advises that it has begun work to plug the ventilation shaft at the former Pike River Mine. The mine team and contractors have successfully placed a high-strength expanding resin into the shaft and have begun topping that with a layer of concrete. Once the concrete has set, the remaining area will be filled with an expanding foam material which will also be topped off with a final layer of concrete.

Because this is a very remote work site with many hazards, we were unable to host a visit. Pool imagery was recorded this afternoon (four photographs available here --http://www.hightail.com/download/OGhmYUlrdGpTSUFpR01UQw -- and a web-sized rough edit video here -- PikeConcretePour.mp4). The video includes a short explanation from project director Mark Pizey, the audio of which may be of use to radio broadcasters.

The four photographs in the drop box show members of the Solid Energy crew on the vent shaft platform preparing for and receiving the first helicopter-lifted load of concrete at around 2.45pm today.

Project director Mark Pizey (Solid Energy’s Manager Health, Safety and Environment) is hopeful this first phase of the project will be completed by Christmas. A schematic explaining the project stages is here http://www.beehive.govt.nz/sites/all/files/Pike_River_exploration_diagram.pdf

The shaft sealing is needed to fully stabilise the environment in the mine. The bottom 40-50m of the shaft – originally about 100 metres deep – is filled with rock from an earlier collapse. The remaining area which is being filled in this phase of the project is approximately 700 cubic metres in volume. At the same time, planning is underway for the project’s next phase – drilling additional boreholes into the main tunnel.

Background

In early September 2013 the Government announced it had approved conditional funding of a staged plan to re-enter and explore the main entry tunnel at the former Pike River Mine up to a rockfall approximately 2.3 km in from the mine portal.

The work is being carried out by Solid Energy, which bought the assets of the former Pike River Coal business in July 2012 and undertook to do its best to develop a safe plan to explore the main tunnel. The tunnel re-entry and exploration project is subject to on-going assessment of the safety and technical feasibility as each stage is undertaken. It does not include entry into the actual mine workings. Solid Energy believes it is not possible to safely carry out a standalone re-entry of the abandoned workings, except perhaps as part of a wider commercial mining operation.

The conceptual project plans for the tunnel re-entry were developed by a group of mining experts, including Solid Energy staff, independent mining consultants and the New Zealand Mines Rescue Service, with oversight from the Ministry of Business, Innovation and Employment's High Hazards Unit. An independent panel of experts with experience in mine recovery and work of this complexity and risk (mining engineers and ventilation and risk management specialists) formally assessed the risks of the plans. Progressive approvals by the Solid Energy Board and on-going monitoring are required for all stages of the project.

ENDS

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