USCG: Gulf of Mexico oil spill greater than estimated

New data provided indicate that the total volume of oil discharged from the damaged pipeline off Louisiana, may be as much as 16,000 barrels (672,000 gallons), rather than the 9,350 barrels (392,700 gallons) initially reported, the US Coast Guard informed.

On Wednesday, LLOG reported a revised estimated volume of unaccounted-for oil to the Coast Guard and BSEE, after additional data became available.

Namely, the USCG and the Bureau of Safety and Environmental Enforcement (BSEE) continue to respond to the oil spill that started on 13 October, approximately 40 miles south east of Venice, Louisiana. Both 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.

As informed, 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 remain on standby.

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 approximately 5,000 feet under water. 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.

    “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 U.S. 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.”

The cause of the incident is under investigation.