Fired up for ice and snow roads


By Nancy Erickson

Alaska Water Tanker

More than triple the number of miles of ice and snow roads were built on the North Slope this construction season than last season.

A document released by the Alaska Department of Natural Resources in February outlined this past winter’s activity. The report stated that about 200 miles of ice roads and 283 miles of snow roads were built to facilitate oil produc­tion activities, exploration drilling and cleanup of old wells in the National Petroleum Reserve-Alaska, or NPR-A, this past season. That compares with 135.5 total ice road construction miles in the 2016-17 season. 

ConocoPhillips led the efforts, pounding down 140 miles of ice and snow roads. Cruz Construction built a 30-mile access road from Endicott to the Badami pad for Glacier Oil & Gas. ENI Petroleum planned 6 miles of road and 6 acres of pad in support of its Nikaitchuq off-shore operations. Hilcorp Alaska LLC built a 14-mile resupply road to the Northstar Island in the Beaufort Sea, as well as 8 miles in the Milne Point Unit. Caelus Energy Alaska rebuilt its 7.5 mile supply route to the offshore Oooguruk drill island. And Olgoonik Construc­tion Services built ice pad and ice access for plugging and abandonment of five wells in the NPR-A, all according to the DNR document.

That was fewer miles than expected overall, due to cancellation of proj­ects for various reasons, according to Melissa Head, Northern Oil & Gas Team Manager for DNR’s Division of Mining, Land and Water. This season’s activity took place more in the western edge of the Slope’s industrial area with some extending into the 23-million-acre petroleum reserve.

 

Narrow windows

The fleet of rolligons and rimpulls used in building ice and snow roads begin shutting down their engines in late April or early May, as Arctic temperatures begin edging towards spring. Tires on these huge vehicles are called “bags” and are designed to carry large loads with extremely low ground pressure, Head said. Pressure in the bags can be individually controlled for changing ground conditions.

It’s one of Head’s duties to monitor snow depth and soil temperatures throughout the winter season to determine when to open or close the tundra to general off-road travel. Monitoring stations are located within four tundra opening areas.

According to a DNR fact sheet, tundra is opened to off-road travel in the coastal regions when the soil temperature 12 inches below the tundra surface reaches 23 degrees Fahrenheit with 6 inches of snow cover. Tundra in the foothills areas needs 9 inches of snow before access is allowed.

Depending on the weather, that season could begin any time from early November to as late as January.

“If you just want to have a conver­sation, I’d estimate from January to the middle of April,” said Jeff Miller, vice president of operations for Cruz Construction.

Miller said it’s possible to get a jump on it and stretch the time from the middle of November to the first week of May, but it is project-specific with a lot of constraints.

“There’s so much daylight going on. Radiation is what kills you, and then you can imagine having black tires on ice that draw in all that heat,” he added.

Adjustments are implemented: traveling at night or hauling pickup-style loads instead of heavy tractor loads, he said.

“There are things you can do to make your ice road season long, but it only takes one tiny spot in 30 miles and the whole road is shut down,” Miller said.

 

Bureaucratic steps

All ice road construction on North Slope state lands requires a permit from the Division of Mining, Land and Water, or DMLW, that typically takes three months to obtain and can be issued for a maximum of five years, Head said.

Once a complete permit application is received, DMLW conducts a 14-day agency review and public notice period working with the applicant to resolve any comments received, she said. A written decision addressing a variety of issues is included in the permit application. The permit is drafted with necessary stipulations and includes provisions for a performance bond and insurance requirements. Once the decision is signed, a 20-day appeal period and 10-day commissioner’s reconsideration period commences. It then goes to the applicant for signa­ture but is not effective until the appeal period has ended.

 

Fickle Mother Nature

Machines start to roll when DNR gives the nod for ice road construction to begin.

“Once construction starts, the biggest challenges are driven by weather,” stated Eric Wieman, vice president and general manager for Peak Oilfield Service Company LLC’s North Slope operations.

“If temperatures are below minus 35 Fahrenheit, construction usually is put on hold to limit exposure to personnel and to limit potential equipment breakdowns,” he said. “If conditions are warmer than zero, construction becomes slower as it takes longer for the water to freeze. High winds and blowing snow limit visibility, which can cause construc­tion to stop.”

“Generally ice roads are closed out by May 1, so if a scheduled start is pushed back it shortens the useful ice road season,” he added.

Wieman said the 2017-18 winter ice road season has been a busy one for Peak.

“The level of activity was up slightly from the last couple of years. This slight uptick in activity is attrib­uted to the increased exploration activities in the NPR-A and capital projects in the western North Slope,” Wieman said.

Peak offers a wide range of support services to resource develop­ment companies on the North Slope, including ice road construction, over­land transport using rolligons and equipment maintenance.

 

Right mix of materials

An average mile of ice road construction requires about 1 million gallons of ice and water, according to Amy Burnett, ConocoPhillips’ senior communication advisor. Ice is chipped from shallow areas of lakes that have frozen to the bottom. Water is collected through holes drilled into lakes with thick ice caps.

In a low snow year, snow is hauled in by truck, pushed on to the ice road route and packed down by vehicles approved to travel on exposed tundra. Adequate snowcover this season allowed prepacking of existing snow to begin in November, Burnett said.

ConocoPhillips’ target date to begin ice road construction was Dec. 1, but warm weather this year pushed plans back by about two weeks, said Jeff Osborne, Cono­coPhillips’ NPR-A project lead for roads and pads.

Water trucks or rolligons with water tanks and spray nozzles begin their part of the process when packed snow measures 6 to 9 inches and soil temper­atures within the route area reach 23 degrees, according to DNR’s Head. 

“Often at this point in the process, constructors conduct ‘wheel-walking,’ which is simply taking a large wheeled vehicle over the route while it is being watered to bust up any voids that devel­oped below the packed snow surface allowing water to fill the areas,” Head said. “If these are not broken up, they essentially turn into potholes while the ice road is in use.” 

The route is allowed to thoroughly freeze, and the water/freeze process continues. 

Considering the large work scope and narrow winter window to complete it, segments of the road are completed according to time sensitivities associated with work they support, Burnett said. Ice road construction teams are placed in 10- to 15-mile sections of road and work toward each other.

Ice roads are opened in phases.

“Early openings this year weren’t until the third week of January, with final sections opening in mid- February,” Burnett said.

“In late April or early May, all the ice road team’s work will melt away — and that’s when planning for next winter will begin,” she added.

More routes constructed on North Slope during past winter, report finds

 

Nancy Erickson is a freelance writer living in Moose Pass.