The US Bureau of Safety and Environmental Enforcement (BSEE) has conditionally approved Shell’s two applications for permits to drill (APD) to conduct exploratory drilling activities in the Chukchi Sea, offshore Alaska, under rigorous safety requirements.
Restricting Shell to drill only the top sections of wells at the Burger Prospect, Burger J and V, the APDs prohibit the company from drilling into oil-bearing zones.
The conditions require Shell to stay away from conducting simultaneous drilling activity at the wells and plug and abandon the top section of the first well prior to proceeding with any drilling activity at the second site.
The APDs also define restrictions that are related to marine mammal protection consistent with requirements established by the US Fish and Wildlife Service (USFWS).
On 30 June, a USFWS letter of authorisation (LoA) was issued to Shell to maintain a minimum 15 miles spacing between active drill rigs during exploration to avoid any effects on walruses in the region.
If Shell plans to drill into oil-bearing zones, under BSEE requirements a capping stack should be on hand and deployable within 24 hours.
Said to be a critical piece of emergency response equipment, a capping stack has been designed to shut in a well in the unlikely event of a loss of well control.
Shell’s capping stack is currently positioned on the M/V Fennica vessel, which is on the way to Portland, Oregon, for repairs and once the vessel is capable of being deployed, the company can satisfy the capping stack requirement.
Once the company is ready, it may submit an application for permit to modify the APDs and request to have this restriction reconsidered.
BSEE director Brian Salerno said: "Without question, activities conducted offshore Alaska must be held to the highest safety, environmental protection, and emergency response standards.
"Without the required well control system in place, Shell will not be allowed to drill into oil-bearing zones. As Shell conducts exploratory activities, we will be monitoring their work around the clock to ensure the utmost safety and environmental stewardship."
The LoA requires Shell to maintain trained wildlife observers on all drilling units and support vessels and must stay within explicitly outlined vessel operating speeds in addition to providing daily reports on all vessel transits.
As part of its review, BSEE analysed information submitted by Shell on well casing design, equipment design, testing procedures, safety protocol, third party certifications of key equipment and rig information.
BSEE safety inspectors will be present on the drilling units Noble Discoverer and Transocean Polar Pioneer 24 hours a day in order to ensure compliance with the conditions of the APDs.
Image: Drilling unit Noble Discoverer. Photo: courtesy of Bureau of Safety and Environmental Enforcement.