Deepwater drilling

Moira Baird
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Offshore regulator says tougher rules will apply on a ‘per-well basis’

Offshore oil exploration rig Henry Goodridge. — Submitted photo by Greg Locke

Last year’s Deepwater Horizon well blowout has cast a long shadow over offshore oil and gas drilling — extending to exploration drilling in deepwater frontiers off Newfoundland and Labrador.

Oil and gas companies say they’re carrying out more frequent testing and inspections of equipment designed to prevent well blowouts and paying close attention to the lessons from the U.S. Gulf of Mexico well explosion.

The next deepwater well off Newfoundland will be led this summer by Norwegian-based Statoil Canada in the Flemish Pass.

Located about 500 kilometres east of St. John’s, waters in the Flemish Pass are about 1,100 metres deep.

Statoil is returning to its 2009 Mizzen discovery to drill a delineation well that should quantify the size of its oil and gas find.

Geir Richardsen, Statoil’s exploration manager in Calgary, said the company is focusing on prevention and identifying the potential risks as it sets out to drill its second Mizzen well.

The company will use the drill rig Henry Goodrich, which is rated for water depths of 1,500 metres and is owned by Transocean.

“The most important thing is to prevent anything from happening. That’s absolutely the most important thing,” he said.

“There’s strict preventative maintenance and testing of the BOP (blowout preventer) and function testing of it. All the systems will be tested at key intervals in the well to make sure that they’re operating properly.”

A blowout preventer (BOP) is last line of defence when a potentially explosive surge of oil and gas occurs during drilling. It’s a giant stack of valves that sit on top of a wellhead and is designed to cut the drill pipe, seal it and shut down the well.

Richardsen said Statoil has also hired third-party experts to assess and audit the blowout preventer on the Henry Goodrich and the company’s well-control operations both onshore and offshore.

Early-stage planning

It’s still early days in Statoil’s planning of the next Mizzen well.

The company has not yet filed a drilling application with the regulator, the Canada-Newfoundland and Labrador Offshore Petroleum Board (CNLOPB).

That application sets out what steps Statoil will take in drilling the well and preventing a blowout.

Jim Beresford, Statoil’s drilling project manager in St. John’s, said the company will work closely with the regulator in planning the well.

“There will be close discussions with the regulator on how we proceed and getting their feedback, so it’s really a two-way communication,” said.

“We know the additional oversight that the regulator and Chevron did together, and we’re prepared for that level of oversight.”

Last May, the CNLOPB beefed up its regulations for deepwater drilling in the Orphan basin, where Chevron Canada spudded the Lona O-55 well in 2,600 metres of water.

It was the first deepwater drilled by a local operator since the Macondo well blowout that killed 11 rig workers on April 20, 2010.

By the time that blown-out well was capped in mid-July, it had spewed an estimated 4.9 million barrels of oil into the Gulf of Mexico. BP, the company operating the Macondo well, has estimated it could cost as much as $40 billion to pay for the environmental cleanup, claims and penalties.

As part of its tougher deepwater drilling rules introduced weeks after the Macondo blowout, the CNLOPB:

— created a special committee to oversee Chevron’s drilling operations at every stage of the well, including pressure testing the blowout preventer and cementing the well;

— required more frequent inspections, testing and third-party auditing of the drill rig’s blowout preventer;

— required operational time-outs before drilling into specific well targets to verify that right equipment and procedures were in place.

One well at a time

Max Ruelokke, CNLOPB chairman and CEO, said the board has stepped up its oversight of deepwater wells.

But the extra rules brought in for the Lona O-55 well won’t necessarily apply to each new well drilled off Newfoundland.

“It’ll be on a per-well basis. We do a risk assessment for each well,” he said.

“Everybody in the industry is paying much more attention to ensuring that they’ve got the right BOP selected, that it’s got the appropriate numbers of rams, that it’s in absolutely tip-top condition.

“If there’s any sign of trouble in a BOP now, then you’re going to take the most prudent course of action, which is to shut in the well.”

Deepwater wells in little-known, under-explored areas will get the closest scrutiny from the CNLOPB.

Ruelokke said last year’s rules are mainly for wells with “similar characteristics to the Lona well, where you’re drilling into formations that you don’t know a lot about and where you’ve got deep water.”

Statoil’s Mizzen well may get slightly different treatment.

It will be the third well at Mizzen since 2003. That first well was drilled by Petro-Canada, which discovered non-commercial quantities of oil before abandoning it.

“This is the third well on the same structure,” said Richardsen. “We know the area the sub-surface well. We are not targeting anything unknown.

“It’s not a high-pressure area.”

Ruelokke seems to agree.

“There’s a lot more known about the formation and how to prepare for entering it than would be in a well like Lona,” he said.

“If you’re drilling into a formation that you’ve drilling into previously, we would have less stringent requirements, say, for time-outs.

But some rules won’t vary from well to well.

“The diligence of the inspection and testing of the BOP won’t change,” said Ruelokke.

Meanwhile, a team of three senior CNLOPB managers is reviewing the investigation report on the Gulf of Mexico blowout.

“Are there further changes to be made? I’m absolutely certain that there is.”

Ruelokke said the review is almost complete and he expects to hear from the team before the end of this month.

Gulf of Mexico lessons

Last month, Det Norske Veritas (DNV) issued a report on its forensic examination of the Deepwater Horizon’s failed, 53-foot-tall blowout preventer.

Based in Norway, DNV is an international certifying agency. Its report is part of the U.S. government’s investigation of the well blowout disaster.

DNV concluded the rig’s blowout preventer was unable to completely shear the drill pipe and seal it because the pipe buckled under the force of the blowout and was no longer centred between the blind shear rams.

That left the pipe partially open, allowing crude to gush into the ocean.

The report said the failure of the blowout preventer would have occurred regardless of how it was activated.

DNV recommended the industry more closely examine the design of shear rams to ensure they can cut drill pipe regardless of its condition or where it’s positioned inside the blowout preventer.

It also said its conclusions should be used in the design of future blowout preventers and in modifying BOPs already in use.

Henry Goodrich BOP

The blowout preventer on the Henry Goodrich has two shear rams and multiple pipe rams.

“It is suited for the job we’re doing and provides redundancy in terms of well control,” said Beresford. “It has a deadman auto-shear system.”

Shear rams are designed to cut the drill pipe and seal it, while pipe rams also seal the pipe.

Beresford said the blowout preventer can be activated in three ways.

One is from the drill rig. A remotely operated underwater vehicle can also be sent to the seabed to mechanically activate the blowout preventer and shut down the well.

The third is a deadman switch that activates the shear rams when the hydraulic lines between the rig and blowout preventer are severed.

“The deadman auto shear would be the last resort,” said Beresford.

“The BOP itself is fit for purpose and suitable for the job that we’re gong to task it to do on Mizzen and our other exploration work.”

Richardsen said Statoil also has other drill rigs available in the Norwegian Shelf that can drill a relief well off Newfoundland if necessary.

“They would have to come from the Norwegian Shelf which is actually closer to Newfoundland than the Gulf of Mexico. These would be winterized rigs.”

Organizations: Statoil, Canada-Newfoundland and Labrador Offshore Petroleum Board, Det Norske Veritas BP Petro-Canada

Geographic location: Newfoundland, Gulf of Mexico, Calgary Norway U.S.

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Recent comments

  • yo mama
    April 15, 2011 - 00:16

    Why are you not posting comments?