Oil giant BP on Thursday was poised to resume a critical test on a new wellhead cap after interrupting the test because of an overnight leak in one of the lines, DPA reported.
Thad Allen, the retired Coast Guard admiral who is overseeing the cleanup and containment of the three-month-old gusher, said that the leak had been fixed and BP was "ready to restart" the test procedure.
The leak had been in a choke line that leads out of the side of the 5.5-metre-high new cylinder-like cap that was installed earlier this week. The entire choke assembly had been removed and replaced overnight, Allen said in broadcast remarks.
The test involves gradually closing first the valves and a ram on the top of the new cap, followed by the pipes leading out from the side. When the test resumes, engineers will first slowly close the "kill" line and then the troublesome "choke" line to make sure the cap can withstand the pressure, Allen said.
"We will know as we apply pressure to this as we close it how successful they were in closing this leak," Allen said. "The only reason we would terminate the test (again) was if the pressure drops quickly."
The test could take up to 48 hours and is designed to discover whether the tight-fitting cap placed on the ruptured wellhead late Monday can truly hold down the tens of thousands of barrels of oil spewing from the bottom of the ocean.
The gusher is pushing upward at an estimated 12,000 psi (pounds per square inch, or 825 bar), Allen said.
BP hopes the new cap will totally suppress the gusher until a parallel relief well is finished by middle August. The new well will serve to allow BP to pump cement and heavy mud to permanently seal off the oil reservoir.
But if the new cap does not attain a total seal, at least it will provide a better way to feed the oil to tankers and processors on the surface and reduce the leakage that is destroying the Gulf of Mexico waters and coast.
"The best reason to shutting the oil right now is it allows us to abandon the site if there's a hurricane," Allen said. The US government has insisted that BP come up with multiple backup plans to contain, capture and stop the flow of oil.