Close 

Subsea containment system en route to gulf oil spill

Paula Dittrick
OGJ Senior Staff Writer

HOUSTON, May 5 -- One of three oil leaks from a deepwater well feeding an oil spill in the Gulf of Mexico was stopped, and a subsea containment system was en route to the well, BP PLC reported May 5.

The volume of oil being spilled still remains at 5,000 b/d, said Doug Suttles, chief operating officer of BP Exploration & Production Inc. Remotely operated vehicles cut the top of a drill pipe in 5,000 ft of water and placed a shutoff valve on the drill pipe.

Transocean Ltd.’s Deepwater Horizon semisubmersible drilled the Macondo well for BP and its partners, Anadarko Petroleum Corp., and Mitsui Oil Exploration Co. Ltd. BP is the operator.

An Apr. 20 explosion and fire left 11 crew members missing and presumed dead. The Deepwater Horizon sank on Apr. 22 (OGJ, May 3, 2010, p. 31). The well struck oil and associated gas with the oil being 35° gravity.

A subsea containment system was loaded onto a barge and was en route May 5 for the leak site about 50 miles off Venice, La. Suttles expected crews would lower a large metal structure onto the seabed and over the top of the end of the riser on May 6.

Plans call for the containment structure to be hooked to a riser going up to Transocean’s Discoverer Enterprise drillship during the weekend. Suttles said it’s possible the system could be operational on May 10.But he noted that such a system never has been used in 5,000 ft of water where pressure is 2,500 psi.

“There are a number of challenges,” Suttles said. “It’s very complex.”

US Department of the Interior Secretary Ken Salazar was on the Gulf Coast for the second time in less than a week on May 5. He planned to meet with BP executives in Houston on May 6. Previously, he visited the Gulf Coast and met with BP in late April.

“An incident of this size needs to be an incident from which we learn,” Salazar told reporters during a news conference. “The lesson is there is nothing mistake free. There are risks in everything we do.”

Meanwhile, the oil spill was nearing the Mississippi Delta area and the Chandeleur Islands off Louisiana, US Coast Guard Rear Adm. Mary Landry said, adding that there had been no confirmed report of any oil having reached the shore.

Boom was being put around marshes at the mouth of the Mississippi River. Boats with boom were stationed at the Chandeleur Islands with the intention of trying to stop the oil. The leading edge of the oil is a rainbow sheen consisting of an oil and water mixture, the USCG said.

Calm weather enabled officials to resume controlled burns on open water on May 5. A test burn had been done on Apr. 28 but winds and choppy seas had prevented any more burns. Emulsified oil is burned, leaving a waxy substance that can be picked up by skimmers.

Suttles said subsea applications of chemical dispersants at the wellhead temporarily had been stopped as expected pending a study of the effectiveness of that practice. It’s the same dispersant being used on the surface of the water.

Spill cost estimates
Raymond James & Associates forecast an estimated oil spill cleanup cost net to BP at $2.63 billion, with $1.57 billion coming in 2010 and $1.07 billion coming in 2011.

“The ultimate price tag will depend not only on whether the [subsea containment] dome will prove successful, but also factors that are even more outside BP's control, such as the effect of wind and wave patterns on the spread of oil around the gulf,” RJA analysts said.

Analysts based their cost estimate on a projected $8 million/day cleanup cost during the second and third quarters. BP has said it is spending $6 million/day on the cleanup.

The cost of two relief wells is estimated at $300 million with BP paying for 100%. “Since BP is self-insured, we assume that all of these costs are out-of-pocket expenses,” RJA said.

Contact Paula Dittrick at paulad@ogjonline.com.


To access this Article, go to:
http://www.ogj.com/content/ogj/en/articles/2010/05/subsea-containment.html