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Pre-packing snow along proposed ice road routes saves season for companies doing exploratory drilling on North Slope
Steve Sutherlin PNA Managing Editor
The state first opened portions of the North Slope to tundra travel Jan. 25 — the latest ever tundra travel opening, breaking the previous record set Jan. 14, 1999.
Land closest to the coast was opened first; the geographic line being 69 degrees 40 minutes north latitude in the vicinity of the Franklin Bluffs area, Leon Lynch of the state Division of Mining, Land and Water told PNA.
The late opening was blamed on heavy snowfall earlier in the winter that, despite extended cold temperatures, insulated the ground and kept the frost level from dropping to a level acceptable for ice road construction.
But partial ice road construction was allowed by the state on a case-by-case basis in early January on routes that would lead to drilling sites in the National Petroleum Reserve-Alaska, Lynch said.
Rolligons were used to pack the snow along the routes, he said. Packed snow has less insulating value than loose snow, driving frost levels down more quickly.
Peak Oilfield Service Co. was able to construct 60 miles of road from Meltwater to the Colville River crossing on a pre-packed route, Lynch said. Pre-packing more important this year Pre-packing ice road routes, which has been done for about five years on the North Slope, costs the companies more, but it seems to have paid off this year, Lynch said, with tundra travel delayed unusually long.
Pre-packing can be effective to counteract uncertainties due to the weather, as well as uncertainties due to the permit process, Lynch said.
“We had lawsuits over water permits. Almost every permit was being contested this year — it made pre-packing more important,” Lynch said. “The consistency determinations were challenged through the ACMP process.”
South of the 69 degree 40 minute north latitude line, winter movement is being considered on a case-by-case basis, he said.
Frost levels are marginal where PGS Onshore is doing seismic work near Happy Valley, 80 miles south of Deadhorse, but deep snow there protects the tundra, allowing some work to progress. PGS is doing 3-D seismic at a location 30 miles west of the Haul Road, and it is doing 2-D work at another site 10 miles east of the road.
State officials were frustrated by poor flyingweather the week of Feb. 4, which turned back attempts to visit the PGS locations to measure frost depth and observe activity.
BLM approval Dec. 31 The Bureau of Land Management approved ice road construction and tundra travel on Dec. 31. Usually BLM follows the state lead, but this year has been unusual, Don Mears of BLM told PNA. He said NPR-A seems to be colder than Deadhorse.
Phillips Alaska Inc. has been hauling supplies and equipment by rolligon to its NPR-A Hunter prospect and is building ice roads now, Mears said.
Anadarko Petroleum Corp. is working on ice pads for Altamura No. 1 well, south of Phillips and Anadarko’s Moose’s Tooth discovery in the NPR-A. Once the pad is complete, Nabors Rig 14E will be used, the company said.
Nabors 14E is currently broken down to allow it to be transported to the site by rolligon, according to Jim Denney, Nabors Alaska Drilling Inc. president. Part of the camp is already in place to house pad construction crews, he said.
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