BP has announced that it has stopped oil flowing into the Gulf of Mexico after closing a choke valve on its newly installed sealing cap.
The energy giant began a well-integrity test yesterday, following the deep-sea installation of a three-ram capping stack over the failed blow-out preventer on Tuesday.
BP had announced that it would be closing the capping stack during the test, but it did not expect the flow of oil to stop for a couple of days. However, the company was quick to add that, even if no oil is released during the test, this would not be an indication that oil and gas flow from the wellbore has been permanently stopped.
Information gathered during the test will be reviewed by government agencies, including the federal science team, to determine next steps.
While initial results from the integrity test are positive news for BP, the company cautions that the sealing cap system has never before been deployed at these depths or under these conditions, and its efficiency and ability to contain the oil and gas cannot be assured.
During the well-integrity test, which could take as long as 48 hours, sub-sea containment systems, namely the Q4000 and Helix Producer, have been temporarily stopped.
Also, operations on the first relief well were temporarily stopped while the well was at 17,840ft as a precaution. Operations on the second relief were also temporarily suspended at 15,874ft to ensure that there is no interference with the first relief well.
BP stated that the relief wells remain the sole means to permanently seal and isolate the well.