Two weeks ago, the government put out a round estimate of the size of the oil leak in the Gulf of Mexico: 5,000 barrels a day. Repeated endlessly in news reports, it has become conventional wisdom.
But scientists and environmental groups are raising sharp questions about that estimate, declaring that the leak must be far larger. They also criticize BP for refusing to use well-known scientific techniques that would give a more precise figure.
The criticism escalated on Thursday, a day after the release of a video that showed a huge black plume of oil gushing from the broken well at a seemingly high rate. BP has repeatedly claimed that measuring the plume would be impossible.
Subsea efforts continue to focus on, firstly, progressing options to stop the flow of oil from the well through interventions via the blow out preventer (BOP) and, secondly, attempts to contain the flow of oil at source to reduce the amount spreading on the surface. These efforts are being carried out in conjunction with governmental authorities and other industry experts.
Further investigation of the failed BOP, using remotely-operated vehicles and a variety of diagnostic techniques, has increased our understanding of the condition of the BOP and allowed planning to continue for a number of potential interventions, including for a so-called “top kill” of the well.
This would involve first injecting material of varying densities and sizes (also known as “junk shot”) into the internal spaces of the BOP to provide a seal, before pumping specialised heavy fluids into the well to prevent further flow up the well. Plans for this option are being developed in preparation for potential application next week.
Work continues to collect and disperse oil that has reached the surface of the sea. Over 530 vessels are involved in the response effort, including skimmers, tugs, barges and recovery vessels.
Over 120 flights have been made to apply dispersant to the spill since the response effort began.