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Ion gets permit for Beaufort Sea seismic BOEMRE has issued a permit for an early winter 2-D seismic survey in the Beaufort Sea; Ion will use new under-ice technique Alan Bailey Petroleum News
The U.S. Bureau of Ocean Energy Management, Regulation and Enforcement has issued a geological and geophysical permit to Ion Geophysical for a 2-D seismic survey along the entire length of the Alaska Beaufort Sea outer continental shelf and into the extreme northeast of the Chukchi Sea.
In the interests of avoiding conflicts with other offshore activities, especially subsistence whale hunting, Ion is using a new technique for acquiring seismic data in sea ice: The company anticipates conducting its seismic program between early October and mid-December, after the end of the Arctic open water season when offshore seismic surveying is normally carried out.
Regional survey The huge area that the survey will encompass reflects an intent to obtain regional-scale information about the broad nature of the Beaufort Sea petroleum system, with the resultant data presumably being licensed to companies exploring in the region.
“The purpose of the seismic survey is to collect seismic reflection data that reveal the sub-bottom profile for assessments of geologic origin and potential petroleum reserves,” the environmental assessment for Ion’s survey says. “Ultra-deep 2-D lines, such as those to be collected, are used to better evaluate the evolution of the petroleum system at the basin level, including identifying source rocks, migration pathways and play types.”
In 2006 GX Technologies, a division of Ion, conducted a similar regional survey in the U.S. Chukchi Sea. GXT carried out that survey during the open water season, but Ion later decided to rethink its method of collecting seismic data in the Arctic before returning to the seas offshore northern Alaska.
“We really took a look at what it would take if we wanted to come back to Alaska,” Joe Gagliardi, Ion’s director, Arctic solutions and technology, told the National Marine Fisheries Service Arctic open-water meeting on March 23 when describing Ion’s new approach to seismic data acquisition in the Arctic offshore.
Novel design In a marine seismic survey a vessel tows arrays of air guns that periodically blast sound through the ocean water and into the rocks beneath the seafloor. The vessel also tows what are referred to as “streamers,” often several miles long, carrying special microphones called hydrophones that detect air-gun-blast echoes, reflected from rock strata deep below the sea. Ion has redesigned its equipment to enable the streamers to operate deeper than normal under the water, moving under the sea ice and thus enabling seismic surveying to be done in conditions where ice covers up to nine-tenths of the sea surface.
And to enable a seismic vessel to tow the seismic equipment through the water, the vessel operates in tandem with an icebreaker, with the icebreaker moving ahead, clearing a passage through the ice.
“Really the limiting factor for us becomes land-fast ice in the Bering Straits at the end of the season,” Gagliardi said.
Seismic vessel Geo Explorer will conduct the survey, working in tandem with the icebreaker Vladimir Ignatyuk, according to the survey’s environmental assessment.
IHA and LOA applications Ion has applied to the National Marine Fisheries Service for an Incidental Harassment Authorization for whales and pinnipeds, and to the U.S. Fish and Wildlife Service for a Letter of Authorization for the incidental disturbance of polar bears and walrus.
“Unavoidable impacts to each of the species of marine mammal that might be encountered are expected to be limited to short-term localized changes in behavior and distribution near the survey activities,” the environmental assessment says.
Marine mammal observers will maintain a visual watch for wildlife, to minimize environmental impacts during daylight conditions. At night a thermal imaging camera system mounted on the icebreaker, bright searchlights and night-vision devices will aid in the spotting of marine mammals, the environmental assessment says — presumably dwindling daylight hours as the Arctic winter closes in will necessitate operations after dark.
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