The riser insertion tube tool (RITT) containment system was put into place in the end of the leaking riser on May 16. Operations began during the day to allow oil and gas to flow through the tool up to the drillship Discoverer Enterprise on the surface 5,000 feet above. Produced oil, estimated currently at 1,000 barrels per day, is being stored on the drillship while produced gas is being flared. It is expected that it will take some time to increase the flow through the system and maximize the proportion of oil and gas flowing through the broken riser that will be captured and transported to the drillship. It should be noted that, BP and government agencies are still using the figure of 5,000 barrels per day as the rate of the leak; however, other reputable sources are estimating far more (i.e. between 20,000 to 100,000 barrels per day).
The RITT is a fabricated from 4-inch diameter pipe, fashioned to allow one end to be inserted into the broken riser pipe that is the source of the main oil flow from the MC252 well, and the other to be connected to a drill pipe and riser from the Discoverer Enterprise. The RITT allows the injection of methanol to mitigate against the formation of gas hydrates. This remains a new technology and both its continued operation and its effectiveness in capturing the oil and gas remains uncertain. Other containment options continue to be progressed.
BP indicates it also continues to develop options to shut off the flow of oil from the well through interventions via the well's failed BOP. Plans continue to be developed for a so called "top kill" operation where heavy drilling fluids are injected into the well to stem the flow of oil and gas, followed by cement to seal the well. Options have also been developed to potentially combine this with so-called "junk shot", the injection under pressure of a variety of materials into the BOP to seal off upward flow. Plans for deployment of these options are being progressed with the possibility of deployment in the next week or so. Work on the first relief well, which began on May 2, continues. The DDII drilling rig began drilling the second relief well on May 16. Each of these wells is estimated to take some three months to complete from the commencement of drilling.
"(2) While oxygen levels detected in the layers were somewhat below normal, they are not low enough to be a source of concern at this time. (3) Although their initial interest in searching for subsurface oil was motivated by consideration of subsurface use of dispersants, there is no information to connect use of dispersants to the subsurface layers they discovered. NOAA thanks the Pelican scientists and crew for repurposing their previously scheduled mission to gather information about possible impacts of the BP oil spill. We eagerly await results from their analyses and share with them the goal of disseminating accurate information.
"NOAA continues to work closely with EPA and the federal response team to monitor the presence of oil and the use of surface and sub-surface dispersants. As we have emphasized, dispersants are not a silver bullet. They are used to move us towards the lesser of two environmental outcomes. Until the flow of oil is stemmed, we must take every responsible action to reduce the impact of the oil."
This afternoon (May 17), Janet Napolitano, U.S. Department of Homeland Security; Rear Admiral Peter Neffenger, Deputy National Incident Commander, U.S. Coast Guard; and Lamar McKay, Chairman and President of BP America, Inc. testified before the Senate Committee on Homeland Security and Governmental Affairs, chaired by Senator Joe Lieberman (I-CT) with Ranking Member Susan Collins (R-ME).