Shell gives up completing wells
Shell has given up drilling to hydrocarbon depths on its Chukchi Sea and Beaufort Sea exploration wells this year following damage to an undersea spill containment dome during tests in Puget Sound.
The damage cannot be repaired in time for the spill response barge, the Arctic Challenger, to reach the Arctic, Shell spokesman Curtis Smith said.
Under rules agreed to by Shell in its spill response plan, the barge, with an undersea blowout containment system, must be in the Arctic and near the exploration wells when Shell drills down to depths where oil and gas might be encountered.
The company has permission, however, to do preparatory work on the upper portion of the wells, the “top hole,” with its drillship Noble Discoverer, and this might be done on several wells to give Shell a jump-start on 2013 drilling.
The U.S. Interior Department has given Shell a drilling permit for its first Chukchi Sea well, Burger-A, to do the top-hole work, and applications are pending to do similar top-hole work on other wells including the first well in the eastern Alaska Beaufort Sea.
A second Shell drill vessel, the Kulluk, is in the Beaufort Sea awaiting the end of the annual fall subsistence whale hunt by local Inupiat Eskimos. Shell had agreed to hold the Kulluk away from the drill location until the whale hunt was finished.
Meanwhile, the company began moving its drillship Noble Discoverer back to the Burger-A well location in the Alaskan Beaufort Sea Sept. 19 after the passage of a massive ice floe over the prospect, Smith said. The ship must be re-anchored at the site, Smith said.
“It will probably be 36 to 48 hours before we can resume work on the well,” he said.
Shell has received approval to do “top hole” work on the well and started preparations at the site Sept. 9, but had to pull off the well less than 24 hours later when the ice moved toward the location.
The floe was large, about 30 miles long by 11 miles wide, and moved slowly. It took several days to move over the Burger well location, Smith said.
Shell has permission to excavate a well cellar and install a blowout preventer and set casing to the 1,400-foot level. However, under Interior Department rules the company cannot drill deeper to possible hydrocarbon-bearing zones until it has a specialized spill response barge on the scene.
Despite the setback with the spill barge, preparation work on the exploration wells will help Shell’s effort in 2013. About two-thirds of the time needed to complete the wells is in the “top end” work, the blowout preventer installation and installation of surface casing and casing to the 1,400 depth, Shell vice president Pete Slaiby has said in a previous briefing.
One that work is done, it would typically take 7 to 10 more days to drill down about 6,000 feet to reach the potential hydrocarbon zones.
Shell has invested more than $4.5 billion in its Arctic effort since 2005, when the company returned to Alaska and bid in an Alaska Beaufort Sea Outer Continental Shelf lease sale.
In 2007, Shell mounted a major effort to explore in the Beaufort Sea but was stopped by lawsuits filed by environmental groups and the North Slope Borough, which was concerned about drilling in the area used by bowhead whales in their fall migration.
In 2008, Shell acquired its Chukchi Sea leases in another OCS lease sale and began planning for exploration drilling there.
In 2010, the company’s plans were set back again when the Gulf of Mexico blowout caused the Interior Department to suspend OCS exploration drilling until drilling rules were revamped.
Revisions were completed in 2011, and Shell’s plans were approved by federal regulators for the 2012 program. However, a late summer breakup of ice in the Arctic caused further delays. The mechanical mishap with the spill containment dome is the latest setback.