Drilling In An Arctic Frontier | Chemical & Engineering News
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Web Date: January 6, 2011

Drilling In An Arctic Frontier

Oil Exploration: Drifting ice and low water temperatures present unique problems when planning for an oil spill in Alaska's outer continental shelf
Department: Science & Technology, Government & Policy
News Channels: Environmental SCENE
Keywords: Arctic Ocean, oil exploration, oil spill, chemical dispersants, biodegradation, Royal Dutch Shell
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ICY WATERS
In the Arctic, oil companies will face unique problems due to floating ice.
Credit: Royal Dutch Shell
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ICY WATERS
In the Arctic, oil companies will face unique problems due to floating ice.
Credit: Royal Dutch Shell
DRILLING LANDSCAPE
Shell hopes to start exploratory drilling in the Beaufort Sea later this year.
Credit: Wikipedia
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DRILLING LANDSCAPE
Shell hopes to start exploratory drilling in the Beaufort Sea later this year.
Credit: Wikipedia

Alaska's outer continental shelf is a starkly beautiful ecosystem populated by polar bears, bowhead whales, and arctic seabirds. It's also a bonanza for oil companies. Up to 23% of the oil and 21% of the natural gas remaining in the U.S. might be found there, according to government estimates. So despite the region's fragile ecology and threats posed by extreme weather and icebergs, oil companies are vying for access.

Leading the pack is Royal Dutch Shell, which hoped to begin drilling exploratory wells in the eastern outer continental shelf—specifically, the Beaufort Sea—later this year, according to Richard Ranger, a spokesperson for the American Petroleum Institute, which lobbies on behalf of the oil and natural gas industry. But difficulty getting an air permit has halted Shell's momentum. The company announced in early February that it would delay drilling until 2012.

Shell's plans have raised concerns among scientists and environmental groups. They wonder whether companies can extract the resources safely. They worry that, compared to conditions in other oil-rich seas such as the Gulf of Mexico, the Arctic's low water temperatures and drifting ice pose immense problems for spill cleanup.

A November 2010 report commissioned by the Pew Charitable Trusts concludes that drilling in the Arctic Ocean should only proceed after a full assessment of how an oil company would respond to a spill and how the spill would affect the region's ecosystems.

Curtis Smith, Shell's spokesperson in Anchorage, insists that drilling in the Arctic is safe. "We've been operating in the region for a long time without any significant problems," he says. Since 1983, oil companies have drilled exploration wells at over 65 sites in the Arctic Ocean without a major spill, according to the Pew report.

Six wells are currently operational in the Beaufort Sea, all built on man-made gravel islands built by dredging or by depositing gravel through a hole in the ice. Emergency crews easily could cap a blowout on these islands because the wellheads are above ground.

But Shell's plan for the Beaufort is to drill from a floating platform in waters 150 feet deep, with a wellhead accessible only to divers and remotely controlled underwater vehicles. Just as in the Deepwater Horizon accident, underwater wellheads could make a spill response more challenging, says Richard Steiner, a conservation biologist in Alaska.

In any offshore Arctic spill scenario, ice is the major concern. Steiner says that the worst-case scenario would be a late-fall blowout, because crews would have difficulty containing it before the sea freezes over. "Oil would spread out under the ice and there wouldn't be much you could do about it until June," he says.

For the proposed exploratory phase, Smith says that Shell would drill only during the open-water season, which generally lasts from July through September. But if Shell finds oil and its production plans pass an environmental review by federal and state government agencies, the company's rigs could operate year-round, he says. The company monitors ice floes continually, he says, using satellites, radar, sonar, and visual observations.

But Layla Hughes, an environmental attorney and senior program officer with the U.S. Arctic Program of the environmental group World Wildlife Fund, says the company's permit application requests authorization to drill until the end of October, when ice is already forming. Smith responds that drilling operations could be halted "instantaneously" should ice become problematic. "The specific dates of operation don't matter so much as the extent of ice cover," he says.

Much as a frozen-over sea would hamper cleanup efforts, drifting ice could also cause problems. Research by industry and government groups has shown that ice also can block, tear, or clog the booms and skimmers used in oil spill recovery.

Floating ice also would impede in situ burning, because it would trap oil beneath itself, according to the Pew report. And oil can spread via ice, Steiner says. Oil can become trapped in the cracks and crevices on the underside of pack ice, the large masses that break away from ice attached to shore. These large chunks of ice can then spread the oil as they drift on ocean currents. When the ice melts, the oil then releases from the cracks and crevices into the water.

Ice could also interfere with dispersing the oil, another technique spill responders use to lessen oil's impact on wildlife. In the Deepwater Horizon spill, a significant portion of the spilled oil ended up as microscopic droplets floating in the water column. Wave energy promotes this oil dispersion. But, researchers have shown that extensive ice cover could disrupt dispersion by dampening wave energy, says B. Kenneth Trudel, a senior scientist with SL Ross Environmental Research, a consulting firm in Ottawa, Ontario. Even chemical dispersants—the mixtures of surfactants and solvents that cleanup crews spray onto oil slicks—need waves to work effectively, he adds.

While Arctic ice could thwart dispersant use, the water's low temperatures could actually help spill responders. Laboratory experiments at the National Oil Spill Response Research & Renewable Energy Test Facility, a private contract lab, have simulated wave actions in a massive tank filled with more than 4 million gal of seawater at 0 °C. The experiments showed that dispersants aren't as effective on weathered oil—the dense, tar-like substance left behind after petroleum's volatile components have dissolved away. Oil weathers slowly in the Arctic Ocean, because of the cold. That could leave more time for using chemical dispersants.

But slow weathering due to low water temperatures could have detrimental consequences on the region's ecology. Oil's volatile components—benzene, toluene, ethylene, and xylene—are also its most toxic; the longer they linger in the sea before evaporating, the longer they exert their poisonous effects, according to Joel Kostka, professor of biogeochemical oceanography at Florida State University.

Moreover, oil biodegrades more slowly in the Arctic Ocean than it does in warmer seas, says Ronald Atlas, professor of biology at the University of Louisville. "For every 10 °C decline in temperature, the rate of biodegradation decreases by a factor of two," he says. An oil spill will degrade perhaps one-fourth as quickly in the Arctic, where sea temperatures hover between 5 to 10 °C, than in the Gulf of Mexico, where water temperatures can average 25 °C, he says.

Kostka, who studies marine microbiology in Svalbard, a Norwegian archipelago inside the Arctic Circle, says that while some cold-loving microbes are unique to the Arctic, researchers have shown that many of the microbial species there are the same as in the Gulf of Mexico. These microbes, such as Alcanivorax, oxidize petroleum hydrocarbons during respiration. "They just do it more slowly up there because respiration is a temperature-dependent enzymatic process," Kostka says.

Given the many concerns about drilling in the Arctic, the American Petroleum Institute's Ranger admits that spill prevention would have to be a dominant strategy for offshore Arctic oil production. Once oil spills into a cold or frozen sea, oil recovery would be unlikely to exceed 30% even under the best of circumstances, he says. Other experts suggest the result could be far worse.

Shell says its planned oil spill response infrastructure is up to the task. But Chuck Clusen, director of national parks and Alaska projects at the Natural Resources Defense Council, an environmental group, points out that the Deepwater Horizon spill response involved thousands of vessels and tens of thousands of people deployed from a highly developed coastline. By contrast, Alaska's northern plain has virtually no road system, no port facilities, and few airports, he says. No one knows what kind of damage a major spill might unleash. What's certain, Clusen says, is that recovery from it would take a long time.

This story was updated on Feb. 4, 2011. It previously said that Shell wanted to drill exploratory wells in the Beaufort Sea this summer. But Shell hit a snag when, on Dec. 30, the Environmental Appeals Board sent the company's air permit back to the Environmental Protection Agency for further review. Because it lacked the permit, the company announced on Feb. 3 that it would stop attempting to get the needed permits for Arctic offshore drilling in 2011 and instead focus on drilling in 2012.

 
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