Estimate for Gulf of Mexico Pipeline Spill Rises

On Thursday, the Coast Guard reported that the amount of oil discharged from a damaged pipeline 40 miles offshore of Venice, Louisiana was significantly more than initially reported. The pipeline, operated by LLOG Exploration at its Delta House well site, was secured upon discovery of the leak. The spill is still not expected to reach shore. 

On Wednesday, LLOG reported a revised estimated volume of unaccounted-for oil to the Coast Guard and the Bureau of Safety and Environmental Enforcement, based on additional data. These new calculations indicate that the total volume of oil discharged could be as much as 16,000 barrels (nearly 700,000 gallons), rather than the 9,000 barrels initially reported.

To date, the impact of the spill appears to be minimal. Multiple over flights, remotely operated underwater vehicle inspections and water column samples have not detected any oil. In the event that any significant amounts should reach the surface, skimming vessels from Clean Gulf Associates and the Marine Spill Response Corporation remain on standby.

Surface and subsea trajectory models calculated by LLOG and NOAA indicate that the oil will drift in a southwesterly direction, away from shore. Calculations indicate that the discovery of any recoverable oil is unlikely. The oil was discharged from a small crack in a jumper pipe leading from Delta House Mississippi Canyon Block 209, Well No. 1 to a manifold located on the seafloor. It was pressurized to more than 3,000 psi and located about 5,000 feet under water, and the discharge through a small fissure likely caused the oil to form small particles and disperse prior to reaching the surface.

“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.”