BP captures varying rates in gulf oil spill response

BP PLC said its riser insertion tube tool continues to capture a varying rate of leaking oil and gas from the deepwater blowout, and the company launched a webcam on its web site showing video of the biggest leak on the seabed.

(Updated after news conference: ave flow rate collected is 2,000 b/d)

Paula Dittrick
OGJ Senior Staff Writer

HOUSTON, May 21 -- BP PLC said its riser insertion tube tool continues to capture a varying rate of leaking oil and gas from the deepwater blowout, and the company launched a webcam on its web site showing video of the biggest leak on the seabed.

In a May 21 news release, BP called the riser insertion tool a new technology, saying that “both its continued operation and its effectiveness at capturing the oil and gas remain uncertain.”

Scientists and BP working together previously estimated the rate of the leak at 5,000 b/d. Doug Suttles, chief operating officer of BP Exploration & Production, said the 5,000 b/d estimate continues to be used to design ways to stop the flow from the well.

"There's a huge amount of uncertainty around that number, and it could have a wide range," Suttles said of the 5,000 b/d spill estimate.

Meanwhile, collection rates have varied daily, and the ave being collected is 2,000 b/d, Suttles said during a May 21 news conference in Robert, La.

"Briefly, at points in time, we've collected up to 5,000 b/d," Suttles said. The latest report was 2,200 b/d and 15 MMscfd collected on May 20.

The collected oil is stored on Transocean Ltd.’s drillship Discoverer Enterprise while the gas is flared. The riser insertion tool is a 4-in. steel pipe inserted about 5 ft into a 21-in. damaged riser on the seabed. The end of the damaged riser is about 600 ft from the runaway Macondo well on Mississippi Canyon Block 252.

A blowout resulted in a fire and explosion on Transocean’s Deepwater Horizon semisubmersible rig on Apr. 20, leaving 11 crew members missing and presumed dead. BP operates the block.

A “top kill” procedure to halt the oil spill using the existing blowout preventer could be attempted on May 25, Suttles said, adding BP was gathering equipment and hooking up lines both on the surface and on the seabed. The US Minerals Management Service is reviewing the top kill plans.

Two relief wells also are being drilled. The first relief well is at 8,950 ft of its 18,000 ft target, Suttles said. The BOP for the second relief well was in the process of being tested under the supervision of the MMS.

Flow rate estimate assessed
On May 20, federal officials announced US Coast Guard Commandant and Adm. Thad Allen was supervising a federal Flow Rate Technical Group to assess the flow rate and to provide a report. BP is providing information to this group.

The Flow Rate Technical Group includes scientists from USCG, MMS, the National Oceanic and Atmospheric Administration, the Department of Energy, the US Geological Society, and others.

Allen plans to remain as National Incident Commander for the administration’s oil spill response. As previously announced, Allen plans later this month to step down as USCG commandant. Adm. Robert J. Papp Jr. will become USCG commandant.

Homeland Security Secretary Janet Napolitano and Environmental Protection Agency Administrator Lisa Jackson wrote BP Group Chief Executive Tony Hayward a letter asking that BP directly post information on a web site and update it daily.

Previously, BP provided a live feed to government agencies as well as industry engineers and scientists.

BP elaborates on logistics
”The rate of flow from the riser is determined in a number of ways and by a number of variables,” BP said. “For instance, while the original riser was 19½ in. in diameter prior to the Deepwater Horizon accident, damage sustained during the accident distorted the diameter at the end of the pipe by about 30%.”

A drill pipe currently trapped inside the riser also reduced the flow area by an additional 10%.

“Thus, some third-party estimates of flow, which assume a 19½-in. diameter, are inaccurate,” BP said. “As well, there is natural gas in the riser. Data on the hydrocarbons recovered to date suggests that the proportion of gas in the plume exiting the riser is, on average, approximately 50%.”

Contact Paula Dittrick at paulad@ogjonline.com.

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