Robust Rig Design

31 August 2005 (Last Updated August 31st, 2005 18:30)

When Hurricane Ivan hit the Gulf of Mexico it caused massive disruptions to the production of oil and gas. World Expro asks Frank Glaviano of EP Americas and Chuck Schoenagel of the Minerals Management Service for the Gulf of Mexico, if the criteria used for designing rigs are sufficient for this generation of Gulf storms.

Robust Rig Design

In September 2004, Hurricane Ivan taught the industry that it has much to learn about designing and building the rigs and platforms left behind to face the ravages of high winds and crushing waves. It is especially important as exploration pushes into new terrain, and as deepwater drilling and exploration increase.

Chuck Schoennagel, deputy regional director of the Minerals Management Service for the Gulf of Mexico, was part of a panel of independent and major operators that discussed the petroleum industry and the impact of Hurricane Ivan. The storm toppled rigs and tore apart pipelines, causing the largest shutdown in oil and gas production in the history of Gulf of Mexico drilling. The discussion was part of the ninth annual Gulf of Mexico Deepwater Technical Symposium and Exhibition.

A year after the storm, the Minerals Management Service, a bureau of the Interior Department that manages offshore oil, gas and mineral resources, is surveying companies about the damage to their sites and focusing on three areas: platforms, rigs and pipelines.

"We have more questions than lessons learned," Schoennagel says. Among the questions is whether criteria used in designing such structures are sufficient for the current generation of Gulf storms. One area the bureau is considering is whether platform rigs should be installed more securely and whether the mooring systems on floating facilities are adequate. "Rigs adrift are not acceptable," he says, but four oil rigs were set adrift by Hurricane Ivan. "Rigs adrift are fundamentally not something we want to have, and I don't think it’s something you want to have either."

"Before a storm, the job for both the independent and major producers is to continue to operate as long as possible while safely evacuating thousands of workers."

The discussion offered a glimpse of the work companies put into planning for storms, evacuating their workers, and later returning them and restoring operations. Before a storm, the job for both the independent and major producers is to continue to operate as long as possible while safely evacuating thousands of workers.

"Moving people is not like moving iron," says Frank Glaviano, regional production director for Shell Energy Resources Company. Many of the people working on the rigs live on the Gulf Coast and have families living on the coast. The human factors of evacuation – stress, anxiety and distraction – are part of Shell's considerations in its plan for handling the 850 employees working in the Gulf.

RESUMING OPERATIONS

After the storm passes, each company has the same job of assessing the damage, restoring rigs to their original integrity and condition, and returning to full production and rig operations as safely and as quickly as possible.

Kevin Guilbeau, senior vice president of Dominion Exploration & Production Company, says his company's Neptune SPAR took waves of 86ft and sustained 90mph winds during Hurricane Ivan. About 17% of Dominion’s production in 2004 and 2005 was deferred because of the storm. The company returned to production six weeks after the storm and the Devil's Tower rig resumed production on 1 January.

Other companies had to wait longer to resume operations. The Petronius platform didn’t begin operating again until early March, says Melody Meyer, vice president of Gulf of Mexico operations for Chevron North America Exploration and Production Co.

Underwater Petronius, a fixed structure taller than the Eiffel Tower, performed as it was designed and was not damaged, Meyer says. Up above the waterline was a different matter. The rig showed evidence it was hit by 60–80ft waves. The drilling rig was shifted about 5ft, the living quarters were overturned, and many of the handrails and stairs were torn off.

"Getting back to normal after a hurricane can be a long and expensive process."

Considering the damage to rig moorings and pipelines in the Gulf, Shell's Glaviano says he anticipates more studies on pipeline construction and design. "I don't know if we can ever solve or create a situation where, no matter what, we will never have damage," he says. But as oil demand increases, Gulf of Mexico production and the flow of other energy through Louisiana is taking on a more vital role in world markets.

"The world has changed, and disruptions in supply are noticed much more by the market than they were five or ten years ago," Glaviano says. "Now everyone knows when there's a hurricane in the Gulf of Mexico; [it] means a disruption in the supply, and the markets are adversely affected."

"Our priority is people, assets and production, but we have to keep in mind that Gulf of Mexico hurricanes have become a world event in terms of world fuel supplies." Schoennagel concurred. His office fielded more than 600 telephone calls from the financial industry wanting to know how long production would be adversely affected by Ivan.

"As demand and supply have become just about even around the world, a shutdown in the Gulf of Mexico makes prices soar around the world, which really affects all of us," Schoennagel says.