USCG: No apparent leak from wellhead after rig sinks into gulf
The US Coast Guard reported Apr. 23 that there was no apparent oil leak from the wellhead of a well drilled by Transocean Ltd.’s Deepwater Horizon semisubmersible rig, which settled under the water’s surface in the Gulf of Mexico after an Apr. 20 fire and explosion (OGJ Online, Apr. 22, 2010).
OGJ Senior Staff Writer
HOUSTON, Apr. 23 -- The US Coast Guard reported Apr. 23 that there was no apparent oil leak from the wellhead of a well drilled by Transocean Ltd.’s Deepwater Horizon semisubmersible rig, which settled under the water’s surface in the Gulf of Mexico after an Apr. 20 fire and explosion (OGJ Online, Apr. 22, 2010).
The semi had been contracted by BP Exploration & Production Inc. to drill an exploration well, which had found oil and associated gas in 4,992 ft of water 41 miles off Louisiana on Mississippi Canyon Block 252 near Rigel gas field.
The well had reached a TD of more than 18,000 ft and crews were running casing and doing cementing when the accident happened. Cause of the accident remains under investigation.
USCG Rear Adm. Mary Landry said the Coast Guard, BP, Transocean, and the US Minerals Management Service remained focused on mitigating any potential oil spill. Landry noted the sunken semi possibly contains 700,000 gal of diesel that could spill.
“From what we have observed yesterday and through the night, we are not seeing any signs of release of crude in the subsurface area,” Landry said on Apr. 23. “However we remain in a ready-to-respond mode…to prepare for a worst-case scenario.”
The rig was staffed with a 126 member crews of which 11 remain missing as of Apr. 23 and 115 were evacuated.
BP assisted Transocean in using remotely operated vehicles (ROVs) to assess the well and subsea blowout preventer. A nearby drilling rig was available if needed to drill a relief well, BP said, adding the rig was available to begin activity immediately.
“The combined response team was not able to stem the flow of hydrocarbons prior to the rig sinking,” Transocean said in an Apr. 22 release.
USCG and the companies involved said they continue to monitor visual feed from deployed ROVs with sonar capability in an effort to identify any crude oil that may have the potential to escape from the subsurface well.
White House press secretary Robert Gibbs said President Barack Obama ordered federal agencies to devote all necessary resources to help with the Deepwater Horizon.
Obama was briefed on Apr. 22 by officials from the departments of Homeland Security and Interior, USCG, Environmental Protection Agency, and others. David Hayes, a deputy interior secretary, has been in New Orleans at the USCG command center for much of the week.
David Rainey, BP vice-president of gulf operations, said BP has implemented contingency plans to respond to any subsequent pollution. BP mobilized a flotilla of vessels and resources that includes 32 spill response vessels including a large storage barge; skimming capacity of more than 171,000 b/d, with more available if needed; 1 million ft of boom, offshore storage capacity of 122,000 bbl and additional 175,000 bbl available and on standby; supplies of more than 100,000 gal of dispersants and four aircraft ready to spray dispersant to the spill, and USCG preapproval to use dispersants.
BP Group Chief Executive Tony Hayward issued a statement from London: “There should be no doubt of our resolve to limit the escape of oil and protect the marine and coastal environments from its effects.”
Relatives of a missing crew member filed a lawsuit in US District Court in the Eastern District Court of Louisiana against Transocean and BP, claiming negligence on the part of the companies.
Contact Paula Dittrick at email@example.com.