(This story was updated following afternoon news conference)
OGJ Senior Staff Writer
HOUSTON, May 19 -- BP PLC crews worked May 19 to gradually increase the volume of oil being collected through the raiser insertion tool at the site of a deepwater blowout, and government scientists reported tar balls found in the Florida Keys were unrelated to the Gulf of Mexico oil spill.
Spill response officials estimate the total oil spill at 5,000 b/d, of which 3,000 b/d was being collected on May 19 and taken to Transocean’s Discoverer Enterprise drillship.
BP worked toward making a final decision on whether to proceed with a “top kill” procedure to seal the Macondo well and halt the oil spill. The top kill procedure might be started on May 23-24 depending upon information still being collected from a failed blowout preventer. Meanwhile, two relief wells are being drilled.
An Apr. 20 fire and explosion on Transocean Ltd.’s Deepwater Horizon semisubmersible, which was drilling for BP and its partners on Mississippi Canyon Block 252.
The amount of oil being collected through the riser insertion tool was gradually increased to prevent drawing seawater, which could trigger the formation of gas hydrates, BP said. Collection efforts started on May 16 when 1,000 b/d was contained.
Analysis and tests at a US Coast Guard laboratory conclusively show tar balls from Dry Tortugas National Park, Fla., and from Florida Keys beaches do not match the type of oil from the Macondo well, oil spill response officials said.
Satellite imagery on May 19 indicated a tendril of oil sheen from the spill was in the Loop Current, which could pull the sheen toward the Florida Keys and the east coast of Florida.
The Loop Current could take the oil sheen through the Straits of Florida. The southeastern Gulf of Mexico includes the western Straits of Florida where the US prohibits leasing for oil and gas exploration. However, Repsol-YPF SA and other companies have exploration acreage in that area off Cuba (See map, OGJ, Dec. 11, 2000, p. 42).
“Both the location of the Loop Current and the oil slick are dynamic—moving around from day to day,” said Jane Lubchenco, administrator of the National Oceanic and Atmospheric Administration during a May 18 news conference.
“The proximity of the tendril of light oil to the Loop Current indicates the oil is increasingly likely to become entrained,” Lubchenco said. “In the time it would take for oil to travel to the vicinity of the Loop Current, any oil would be highly weathered and the natural processes of evaporation and dispersion would reduce the oil volume significantly. The oil would also be significantly diminished by ongoing chemical dispersant application.”
Some 640,000 gal of total dispersant had been deployed by May 18 with 53,000 gal having been applied at the seabed and the rest applied on the surface using airplanes. It’s the first time the use of dispersants at the subsea level has been permitted, and government agencies continue to monitor water samples to determine its effectiveness and possible environmental consequences. Dispersants break up the oil so that it degrades faster.
On the surface, controlled burns of oil on open water were used May 17-19. More than 20,000 people worked on oil spill response efforts. About 7.6 million gal of an oil-water mix has been recovered.
Contact Paula Dittrick at firstname.lastname@example.org.