Shell drillship ready to work at Chukchi Sea
Shell’s drillship Noble Discoverer is in the Chukchi Sea and was preparing to begin site preparation for drilling at the company’s Burger prospect on Sept. 6 or 7, company officials said.
Bad weather caused some delays. The drillship was held about 10 miles south of Burger earlier in the week as Shell waited for rough seas to settle, company spokesman Curtis Smith said.
Meanwhile, a second Shell drill vessel, the Kulluk, is in the Beaufort Sea and will be on standby west of its exploration site to give Inupiat Eskimo whalers time to finish their bowhead whale subsistence hunt.
In another positive development for Shell, the U.S. Environmental Protection Agency issued modified air quality permits for the drill ships.
“Once at the drill site, the Discoverer will connect to the eight pre-staged anchors, a process that will take roughly 16 hours,” Smith said. “When the anchors are connected and deemed secure, the Discoverer will begin doing the well preparations.”
Anchors for the drillship were set earlier on the sea bottom at the Burger site, its initial prospect in the Chukchi Sea.
Interior Secretary Ken Salazar announced Aug. 30 that the department had issued a drilling permit to Shell that would allow the company to begin preparation of the drill site.
The Secretary spoke in a press briefing in Washington, D.C.
That work that Interior approved will include construction of a “mud-line cellar,” an excavation in the sea-floor, for installation of a blow-out preventer, as well as the drilling of a 8.5-inch “pilot hole” to test for shallow gas accumulations that may have been missed by seismic surveys.
Once those tests are done, drilling will be allowed to the 1,400-foot level with installation of casing.
Salazar said Shell will not be able to drill further to potential hydrocarbon zones until the Arctic Challenger, a specialized spill response barge, completes inspections in a Bellingham, Wash., shipyard and is on the scene.
Salazar also said no decision would be made on Shell’s request for an extension of a Sept. 24 deadline for drilling into hydrocarbon zones until the Arctic Challenger spill barge has passed inspections.
Because Shell will not be allowed to drill below 1,400 feet until the barge is on scene no decision is needed for now on the deadline extension, he said.
Shell’s Alaska vice president, Pete Slaiby, said that even if the company can only drill the so-called “top holes” this year, it will consider the season successful.
“We got a late start because of ice, but we will have demonstrated a lot of things, mainly that we can work safely,” he said.
About two-thirds of the time needed to drill the well will be spent on the mud cellar and the initial drilling and setting of casing.
Once the spill barge is on the scene, Slaiby said the drillship will have to drill another 6,000 feet, approximately, to reach hydrocarbon zones. Installation of the blow-out preventer and drilling to 1,400 feet is expected to take about two weeks. Once the barge is on scene it will take about 7 to 10 days to drill down to the hydrocarbon zone, he said.
Under rules set by the government Shell must stop drilling into hydrocarbon zones on Sept. 24, but well-testing and abandonment work on the well can be done after that, Slaiby said.
The permit issued Aug. 30 is for the Chukchi Sea well only, and no similar permit has been issued yet for the Beaufort Sea well. However, the Kulluk will not begin drilling until after the end of the fall Inupiat subsistence whale hunt in the Beaufort, which has just started, Slaiby said.
The Kulluk is not under as tight a drilling deadline as the Noble Discoverer. The Interior Department will allow drilling in the Beaufort Sea until late October.
Shell’s exploration sites in both the Chukchi and Beaufort Sea are in areas where hydrocarbons were discovered in previous drilling, so the drilling planned this year is aimed at assessing those earlier results and establishing more reserves.
Shell itself drilled an exploration well as the Burger site as well as two other exploration locations in the Chukchi Sea in the early 1990s and found a large gas accumulation and signs of oil at Burger.
The discovery was not economic at the time, however.
In the Beaufort Sea, Unocal drilled its “Hammerhead” exploration well in the 1980s and made an oil discovery near where Shell now plans to explore.
A few years later ARCO Alaska made an oil discovery at another site nearby, its “Kuvlum” discovery.
Neither of the oil discoveries were economic at the time, however.