Shell completes top-hole work in short Arctic season
Shell was able to complete “top-hole” work on one exploration well in the Chukchi Sea off Alaska’s northwest coast and one well in the eastern Alaskan Beaufort Sea in the few weeks it was able to operate in 2012, the company said.
Shell’s drill fleet has now demoblized in the region, spokesman Curtis Smith said.
Drilling in the Beaufort Sea ended at midnight Oct. 31, as required by federal permits, while drilling in the Chukchi Sea ended two days earlier, Smith said.
“We feel very good about what we have accomplished. We drilled in 2012. Despite problems with ice, we proved to our stakeholders that we can operate safely and responsibly in the Arctic,” he said.
The drillship Noble Discoverer, which was working at Shell’s Burger prospect in the Chukchi Sea, passed through the Bering Strait and has moved out of northern waters. The mobile drill structure Kulluk, working in the Beaufort Sea, was to be towed out of the region.
The Kulluk will be stored in Dutch Harbor, in the Aleutians, for the winter. It is not yet certain where Shell will store the drillship Noble Discoverer, Smith said.
The top-hole work completed included the installation of casing to approximately 1,500 feet, a point above any potential oil-bearing reservoir intervals, as well as the placement of a blowout preventer on top the casing on the sea-floor.
Federal permits for the work allowed Shell to drill only to a point above the potential oil reservoirs because a specialized spill barge required to be on site was delayed in its travel to Alaska.
Smith said Shell is hoping for a more normal ice year in 2013, which could allow the company to get its ships back to the Arctic in mid-July. There was heavy ice in the Chukchi Sea this year, which delayed the arrival of the fleet.
Also, the Noble Discoverer had to pull away from its location for several days to allow a large ice floe to pass. There were no other ice-related delays in the Chukchi drilling or so far in the Beaufort this year, Smith said.
“Although our work was interrupted by the ice floe it did show that we can successfully forecast an ice problem and safely move the ship off the well,” Smith said.
Such interruptions are actually common. Every one of the exploration wells Shell drilled in the Chukchi Sea in the 1980s and 1990s experienced at least one drilling interruption caused by ice. Drilling by other companies in the Beaufort Sea was also periodically interrupted by ice in the 1980s, although no Shell drilling experienced the problem.