It’s understandable that oil spills attract a glut of media attention when they occur. After all, images of oil gushing from drill pipes and oozing across the sea are practically, and sadly, made for the cameras.
Yet the behind-the-scenes efforts to prevent and respond to spills in increasingly effective ways receive little attention on the international stage.
And here, perhaps, is where the truly riveting stories lie.
As more offshore areas become open to exploration – largely as a result of government policies – highly vulnerable areas such as the Arctic have prompted operators to band together and tailor traditional oil spill prevention and recovery methods to more hostile environments as well as develop new methods.
Battling sea ice, cold temperatures, darkness and remote locations, they have their work cut out for them. But along the way they have learned that while an oil spill in the Arctic would be detrimental to some of the most diverse species of marine mammals in the world, certain aspects of the Arctic environment can actually make a recovery operation more feasible.
Prevention Is (Low) Key
For Mitchell Winkler, manager of Arctic Technology for Shell, oil spill pollution prevention is an area that deserves more of the spotlight.
Winkler presented some of the industry’s latest oil spill prevention and recovery methods at the Arctic Technology Conference in Copenhagen, Denmark, in March.
“Incident prevention is one of the primary priorities of oil and gas operators through exploration and production. But effectiveness of prevention is hard to show other than through the use of statistics, which are not always intuitive,” Winkler said.
“Very often public attention is focused on the more visible emergency response aspects of a major spill,” he added, “without consideration of the risk-based approach the industry takes to ensure that the likelihood of such an event is very low.”
While incidents such as the Macondo blowout in the Gulf of Mexico and the Montara oil spill in the Timor Sea stand out in most people’s minds, few realize the industry successfully drills approximately 80,000 onshore and offshore wells every year without much ado.
This, in large part, is the result of all operators’ desire to avoid oil spills and to collaborate with each other to do so.
“The oil and gas industry does not compete when it comes to health, safety and the environment,” Winkler said.
All adhere to best practices, which include:
- Safe and reliable drilling equipment, including rig and support vessels.
- Primary controls and barriers, including mud, casing and cement.
- Monitoring by competent and trained individuals.
- Secondary controls and barriers, including blowout preventers.
On the recovery side, best practices include:
- Source control measures, including capping stacks and subsea isolation devices.
- Oil spill response plans.
Arctic Application
Exploring in the Arctic is really no different than any other place in the world in terms of commitment to prevention and preparedness for response, Winkler said.
“However, specific Arctic challenges can significantly affect equipment selection and logistics,” he said. “In some cases, Arctic-specific controls and barriers may be required to supplement the best practice offshore well design.”
(It has been widely reported that Shell has had to alter its exploration plans in the Chukchi Sea after a lawsuit filed by concerned environmental groups against the U.S. Department of the Interior resulted in a supplementary environmental impact statement from the U.S. Bureau of Ocean Energy Management.)
If not properly addressed, sea ice features pose one of the greatest dangers when it comes to Arctic exploration, Winkler said. While moving surface ice can damage exploratory wells not protected by fixed platforms, ice keels, which can be 30- to 100-feet deep, also pose a threat to critical parts of the well, including the wellhead and blowout preventers.
To avoid sea ice-related risks, exploration is often conducted during open water seasons. If ice incursions are a threat, they are appropriately planned for, Winkler said. Surface detection, forecasting and taking protective measures for critical parts of the well are methods used to keep drilling rigs safe.
Production wells, on the other hand, are designed for year-round operation.
“As the Arctic environment grows warmer, sea ice actually becomes more dynamic as overall ice cover in the area is reduced,” explained Richard Glenn, a geologist and vice president of Lands and Natural Resources for the Arctic Slope Regional Corp. (ASRC), established in 1972 to manage native Alaskans’ lands and resources.
Ironically, more icebreakers are needed to facilitate vessel mobility in the Arctic Ocean, Glenn said.
The ability to predict weather changes, ocean currents and ice movement patterns can play a significant role in prevention, Winkler said. Critical operation curtailment plans include understanding where ice is located in relation to the drilling sites and the time it takes to temporarily plug and abandon a well to make it safe before the ice reaches the drilling location.
Furthermore, by putting the critical parts of a well in mud-lined cellars, they are protected from deep field ice features that could cause damage, Winkler said.
Permafrost, which is soil at or below the freezing point of water for two or more years, also can be an issue, as it can melt during drilling operations and jeopardize the integrity of a well. Insulating drill pipes or chilling the drilling mud mitigates this risk, Winkler said.
“No private or industrial activity is entirely risk free,” Winkler reminded. “But at every stage of an Arctic project’s planning and operations, operators embed spill prevention practices and procedures, conduct exhaustive risk identification and implement comprehensive risk management plans.”
Ramping Up Arctic Response
The Chukchi and Beaufort seas are home to a broad range of marine wildlife, including ice seals, walruses, polar bears and baleen and toothed whales, according to the U.S. Geological Survey. For endangered species, such as the bowhead whale, any oil pollution could further jeopardize their survival.
Understanding the fragility of the Arctic environment, operators and academics have researched the area for decades in experimentation of oil spill response technology, Winkler said.
Oil spill response methods for application in ice are based on decades of research that have provided a strong science-based understanding of the environment, which is essential to assessing impacts and designing mitigations.
“Wherever the industry operates, safety of people and protection of the environment takes priority over all else in the business,” he said.
After the Macondo incident, the International Association of Oil and Gas Producers established a global forum to improve and extend safe practices. The forum, called the Global Industry Response Group, was charged with sharing experiences, analyzing incidents, advocating harmonized standards and communicating good practice, and promoting continued research and development.
After being delayed by the Macondo oil spill, the Arctic Oil Spill Response Technology Joint Industry Program (JIP) hit the ground running in 2012 tailoring conventional oil spill response practices to extreme environments.
The JIP is sponsored by nine operators, including Shell.
In fact, lab and field experiments have shown that Arctic conditions can aid in the response to a spill, Winkler said.
“The benefit of the Arctic is the ice can act as a natural boom and prevent oil from spreading,” he said. “The challenge with oil is that it has a low viscosity and spreads very quickly. It’s a major impediment to mechanical recovery, or the skimming of oil from the water’s surface.
“That’s why booms are used,” he added. “They increase the thickness of the oil and make skimming more efficient.
“Broken ice conditions are the best,” he added, “because they trap the oil and increase the encounter rate.”
If mechanical recovery efforts are not feasible, industry must resort to in situ burning – the burning of oil on site to reduce water pollution, or dispersants – which can dissipate large amounts of oil from the sea surface.
In such cases, cold temperatures can actually slow the evaporation rate of lighter oil and lengthen the “window of opportunity,” which is defined as the period of time from when the oil hits the water to the time it can be burned or addressed with dispersants, Winkler said.
The JIP currently is exploring cutting-edge alternatives that act as chemical booms. Chemical surfactants, known as herders, can be rapidly spread across a water surface.
When surfactants reach the boundary of an oil slick, they cause the oil to contract to a new, thicker equilibrium state. The slick thickness produced by herders provides favorable conditions for effective burning without the need for containment booms.
The JIP currently is looking at conditions under which herders are most effective and will be testing them in a 300-foot by 300-foot manmade basin just outside of Fairbanks, Alaska at the end of April, Winkler said. Just three feet deep, a simulated ice field will be created for the purpose of spilling oil in the basin’s center. Manned and unmanned aircraft will be used to spray the herder and ignite the oil.
“We know conditions in which mechanical booms can be susceptible to ice damage,” Winkler said. “The herder would provide another tool to address that damage risk and increase the overall robustness of operation repair.”
All Aboard
Drilling in Arctic seas poses more than technical challenges. Indigenous people, primarily Alaskan Inupiat, living and subsisting on Alaska’s North Slope, have a vested interest that the Chukchi and Beaufort seas remain unpolluted.
Although Glenn said the Inupiat who occupy the villages along the state’s northern coast have concerns about oil spills, they are forming alliances with companies such as Shell to galvanize an oil spill response team.
Since 2006, Shell has hosted more than 600 meetings with Alaskan communities on the North Slope to share exploration plans, answer industry-related questions and train citizens to actively aid in a response operation.
Shell entered into an unprecedented partnership last year with the ASRC and six of the villages it represents. The Arctic Inupiat Offshore LLC gives participating Inupiat the option to acquire an interest in Shell’s acreage and activities on its leases in the Chukchi Sea, Glenn said.
Balancing their interest in Shell’s potential petroleum plays with a need to protect their environment, some Inupiat have participated in oil spill training and learned how to deploy booms at certain drilling sites.
Furthermore, by storing onshore and offshore vessels and other equipment on the North Slope, Shell’s response time during an oil spill has been significantly reduced.
“The skimming capabilities on vessels and the stockpiles of dispersants are all local. Maritime assets are specifically assigned for oil spill response,” Winkler said.
“For Alaska, it’s unprecedented in terms of preparedness,” he added. “If we had an incident, unlike other parts of the world where you would fly equipment in, we have the equipment and people in place to mount a response starting at hour one.”