The amount of oil spilled in the Gulf of Mexico a week ago may be around 16,000 barrels, almost double from the initial estimates, according to the United States Coast Guard.
The offshore oil and gas operator LLOG Exploration Offshore earlier informed that the oil released from a damaged pipeline at the Delta House floating production facility was estimated in the amount of some 7,950 to 9,350 barrels.
The USCG and the Bureau of Safety and Environmental Enforcement (BSEE) have been coordinating with the responsible party and the National Oceanic and Atmospheric Administration to locate and respond to any oil that reaches the surface.
Multiple daily over flights and remotely operated underwater vehicle inspections have been conducted with no recoverable oil detected.
Skimming vessels from Clean Gulf Associates and the Marine Spill Response Corporation also remain on standby.
USCG informed that surface and subsea trajectory models calculated by the responsible party and NOAA indicate that any discharged oil will drift in a southwesterly direction and is not expected to impact the shoreline.
Calculations indicate that the discovery of any recoverable oil is unlikely due to the depth and pressure at which the oil was released.
The oil was discharged from a small crack in a pipeline that was pressurized to more than 3,000 psi and located some 5,000 feet under water, 40 miles southeast of Venice, Louisiana. This high-pressure discharge through a small opening likely caused the oil to be broken down into small particles and disperse into deep-water currents prior to reaching the surface.
Water samples taken along the trajectory path at various depths have not detected the presence of oil, USCG confirmed.
“While the reported discharge amount is very significant, we are confident in the calculations completed by the LLOG and NOAA scientists,” said Cmdr. Heather Mattern from US Coast Guard Marine Safety Unit Morgan City, Louisiana.
“Additionally, the lack of any recoverable oil identified by over flights and subsea inspections conducted throughout the past week supports this explanation,” Mattern added.
The flowline release began in the morning hours of October 11 from a fracture in a jumper pipe leading from Mississippi Canyon Block 209, Well No. 1 to a manifold located on the seafloor.
Once identified, the pipeline leak was isolated and stopped on Thursday morning, however, the incident was said to be the largest oil spill in the US since the 2010 Deepwater Horizon catastrophe, Bloomberg earlier reported.
The cause of the incident is under investigation.