Bringing Muskrat Falls power means drilling deeper than ever before
Workers on the Muskrat Falls hydroelectric project are breaking new ground as they drill holes deep under the sea to house the underwater cables bringing power from Labrador to Newfoundland.
The holes travel 1.2 kilometres on the Labrador side, and almost double that distance on the Newfoundland side — drilling through that amount of land to get to the ocean floor has never been done before.
When completed, overhead transmission lines will carry the power to Forteau on the Southern Labrador coast. From there, underwater cables will cross the straight of Belle Isle to bring the power to Newfoundland.
Subsea cables are nothing new, but the Strait of Belle Isle is known for nasty weather conditions. Northern winds often blow icebergs that are up to 70 metres deep, so workers need to make sure they drill deep enough to clear the bottom.
"Basically we drill out on the downstream side of the bank better than 70 metres and there's one in a 10,000-year chance that one of those icebergs is going to contact one of these cables," said Greg Fleming, Nalcor's marine crossing project manager.
It may be the longest landfall drilling, but Fleming said Newfoundland and Labrador has plenty of deep drilling activity to learn from.
"We've applied oil field technology to it. The bits are oilfield technology. The mud system is oilfield technology as well as the directional and the directional is how we control the bit. And that's allowed us to get extremely smooth holes and have extremely good productivity," he said.
Crews are putting the finishing touches on the drilling in Forteau. They'll start in on the Newfoundland side this week. Once that's done, it's time to lay the power cables.
"We've got a construction season in 2015 where we install land cable and in 2016 where we install the marine cable and place the rock protection," Fleming said..
Eventually, 30 kilometres of cable will cross the Strait of Belle Isle. The cable will connect with transmission lines on the island to carry power to Newfoundland and Labrador households by 2017.