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Laying out the plan Shell describes its oil spill response arrangements for the Arctic OCS Alan Bailey Petroleum News
Worried about continuing delays in the permitting of Shell’s planned exploratory drilling in Alaska’s Beaufort and Chukchi seas, Sen. Lisa Murkowski met with Shell executives on July 11 for a briefing on the company’s oil spill prevention and response plans. Concerns about the potential for an Arctic offshore oil spill form one of the key issues in the debate over the pros and cons of Arctic outer continental shelf oil exploration.
Shell has assembled an oil spill response fleet for on-site support of its planned Arctic offshore drilling operations. In the open water season of 2012 the company plans to drill in the Chukchi Sea using the drillship Noble Discoverer and in the Beaufort Sea using the floating drilling platform the Kulluk.
Murkowski invited the media to attend the Shell oil spill briefing, with reporters able to observe the briefing and then ask questions of both Shell and Murkowski. Asked for the reason behind this rather unusual meeting format, Murkowski said that she wants an “open story” about Shell’s oil spill response plans and that Alaskans have a right to know what the company is proposing.
Murkowski also said that she herself needs the latest information about how Shell has changed its oil spill contingency plans following the Gulf of Mexico oil spill disaster.
“I need to have these answers for myself so that I can either be an advocate or a critic,” Murkowski said.
Self-contained Shell’s essential contingency plan concept is to have oil spill response equipment available, on-site at drilling locations, and staged at strategic points, ready to swing into action in the event of a problem. This self-contained response capability would also include the necessary personnel and supplies.
The company already has extensive experience of operating in remote regions with little support infrastructure, including areas within the Arctic, Pete Slaiby, Shell’s Alaska vice president, told Murkowski.
Shell will use ice capable equipment for its exploration drilling program, although the company will be working in open water conditions during its planned 105-day drilling season, Slaiby said.
Shell has emphasized that its prime focus is the prevention of oil spills through procedures such as effective well planning and the use of remote oversight of drilling operations. And Alaska OCS exploration wells present a significantly lower blowout risk than deepwater wells in the Gulf of Mexico because of the relatively shallow water in the Alaska offshore and the relatively normal pressures in Alaska oil reservoirs, Slaiby said.
While the extreme water depths in the deepwater Gulf of Mexico resulted in a very wide oil slick when oil from the Macondo well fanned out toward the surface, the slick resulting from oil rising through shallow Arctic water would extend over a relatively small area, Slaiby said.
New technology After seeing the difficulty of stemming the oil flow from the Macondo well in the Gulf of Mexico, Shell has been moving forward on the development of two new well capping and containment devices for use in the Arctic. So, if there were to be a well blowout, and if the well’s blowout preventer recessed into the seafloor were to fail, the first response would be to cap and kill the well, to stop the escape of oil into the ocean water, the Shell executives explained.
The first of these devices, a capping system, could be lowered onto the well bore and clamped into place, explained Mark Duplantis, Shell Alaska well delivery manager. This system will have blind rams for sealing the drill pipe, a conduit for flowing oil to storage vessels at the surface and the capability to allow drillers to kill the well by re-entering the well bore or by injecting fluids into the well, Duplantis said.
The second device is a containment dome designed to be lowered through the water, over the top of the well, to gather oil escaping from the well and direct that oil though piping to surface vessels.
Oil recovery plan A well control problem would also trigger a plan for the recovery of oil, to deal rapidly with any discharge of oil into the sea, said Geoff Merrell, Shell’s Alaska emergency response coordinator. This plan includes three tiers of oil recovery: recovery near the well site; recovery near to shore; and recovery onshore and along the shoreline, Merrell said.
Each of Shell’s two drilling operations will have a purpose built, ice-capable spill response vessel on site, ready to swing into action if necessary, supporting any well site oil recovery operation, Merrell said. Shell already has one of these vessels, a new oil spill response vessel called the Nanuq, in operation, while another, currently known as Hull 247, is still under construction. The Arctic Endeavor, an ice strengthened barge, would support nearshore response activities.
The vessels will be fully equipped with boom, skimmers, workboats and other oil spill response equipment, while a 513,000-barrel capacity, ice-class, double hulled tanker would store recovered oil.
If Shell is drilling in both the Chukchi and Beaufort seas the company will position both the tanker and the spill containment system offshore Barrow, from where these assets could reach either drilling operation in about a day in ice-free conditions, Slaiby said.
Strategically positioned For the shoreline and onshore aspects of a response, Shell has pre-staged response equipment at strategic sites and has contracted with spill response cooperative Alaska Clean Seas for onshore response operations. Response plans include the protection of certain shoreline sites that have heightened environmental sensitivity.
Peter Velez, Shell oil spill response team leader, told Murkowski that Shell has enough equipment to respond independently in either the Chukchi Sea or the Beaufort Sea to the largest foreseeable spill at any of Shell’s drilling sites. However, should it prove necessary, Shell also has access to caches of spill response equipment at worldwide depots, Slaiby said.
Large items of equipment might have to come in through Dutch Harbor in the Aleutian Islands, but much of the equipment could be flown in, perhaps through Barrow or the Chukchi Sea village of Wainwright.
“It’s just a question of picking up the phone,” Slaiby said. “A lot of it is transportable by air and it’s packaged so that it can be transported quickly.”
Asked about how Shell would deal with rough weather conditions that might occur in, say, the Chukchi Sea when conducting a spill response, Slaiby said that Shell has long experience of operating in regions such as the North Sea and the Gulf of Mexico, where winds can be stronger and waves higher than in the Chukchi.
Burning and dispersing Murkowski asked about the practicalities of using the in-situ burning of oil or dispersants as response techniques in the Arctic offshore.
In Arctic conditions the slow rate of evaporation of the more volatile components of crude oil would enable the burning of the oil to be possible for a longer period after a spill than in warmer climates, Velez said.
For the same reason, dispersants would remain effective for a relatively long time after an Arctic spill, he said. Dispersants would prove particularly effective in situations where ocean wave action could add energy to the dispersal process, he said. Velez said that research done over the past couple of years in Barrow and involving the University of Alaska demonstrated that the toxicology impact of dispersant chemicals on organisms that Arctic mammals feed on is “basically non-existent.”
Relief well drilling The drilling of a so-called “relief well” to plug the original well is the ultimate means of bringing a well blowout to an end. Each of Shell’s drilling vessels will carry an extra blowout preventer for relief well drilling — if there were to be a blowout the drilling vessel engaged in the drilling operation should be available to work on the relief well, Slaiby said. However, if that drilling vessel were to be incapacitated, Shell’s other drilling vessel operating in the Beaufort Sea or Chukchi Sea would drill the relief well, with the vessel able to transition to the problem well site in two to three days, Slaiby said.
Shell anticipates that it would be possible to drill a relief well at any of its Arctic Alaska drill sites in less than 30 days, Slaiby said. The company plans to complete its drilling operations by the end of October so that, with continued drilling possible into November or December, there would be sufficient time for relief well completion, he said.
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