BP PLC (BP, BP.LN) said Monday that it has successfully installed a new sealing cap as part of efforts to stop oil from gushing out of a broken well in the Gulf of Mexico.
The cap was installed at about 7 p.m. central time (0000 GMT), the company said in a statement. Starting Tuesday, the company will begin a series of integrity tests to ensure the cap is working.
The company said once the testing starts it doesn’t expect any oil to be released into the ocean.
The new cap is the U.K. oil giant’s latest attempt to stop the flow of oil from the Macondo well while the company drills relief wells nearly a mile below the surface that it hopes will permanently plug the leak.
The sealing cap system hasn’t been used before at the depths or conditions of the Deepwater Horizon, BP said, adding that the system’s “ability to contain the oil and gas cannot be assured.”
Federal and independent scientists have estimated that between 35,000 and 60,000 barrels of oil have been flowing into the Gulf from the broken well each day.
Working with a vessel called the Q4000 and a more loosely fitting cap that was removed Saturday to allow installation of the new device, BP had managed to capture about 25,000 barrels of oil a day. The company reported that about 4,055 barrels of oil and 9.5 million cubic feet of natural gas were flared on the Q4000 vessel between midnight and noon on Monday.
BP launched a new containment vessel Monday, the Helix Producer, and expected to have oil from the well reaching that ship by Monday evening. The ship has been near the well for about two weeks but was delayed from starting containment operations by bad weather and technical problems.
With the new cap and risers, or pipes, that will be connected to the cap, BP said it expects to be able to recover 60,000 to 80,000 barrels of oil a day.
BP expects the integrity tests, which could last anywhere from six to 48 hours, to show whether and how much oil is flowing through the well casing. If the pressure in the casing is high, that’s a good sign and shows the wellbore is intact and pulling up all, if not most, of the oil flowing out the Macondo well, BP Chief Operating Officer Doug Suttles said earlier on Monday. If the pressure is low, it means oil is escaping from the casing and the company may have to reconnect previous containment devices, he said.
A key risk for the new cap is that hydrates might form at the bottom of the capping stack, preventing the cap from properly latching shut, Suttles said. The company plans to inject glycol to prevent hydrates from forming, he said.
The company reiterated late Monday that the relief wells remain the “sole means” for permanently stopping the leak.
BP has been working to contain the leak for more than 12 weeks after Transocean Ltd.’s (RIG) Deepwater Horizon exploded and sank, killing 11 workers and unleashing the spill that has fouled the coasts of at least four states and killed sea creatures and birds.