Cap holds in oil leak as BP analyzes well structure

Released on - Saturday,17 July , 2010 -19:14

A cap placed over a leaking Gulf of Mexico oil well is still holding back spilling crude, but the results of tests on the well's structure require more analysis, BP said on Saturday.

"We're feeling more confident that we have integrity," BP senior vice president Kent Wells told reporters in an early morning briefing.

"At this point there's not evidence that we don't have integrity," he said as a second day of tests on the condition of the wellbore below the seabed continued.

The tests, which involve multiple pressure readings, began Thursday, when valves on the cap were sealed, choking off the flow of crude into the Gulf for the first time since the spill began in April.

Wells said indications from the critical tests were that the wellbore was withstanding the pressure created by sealing the leak from above, but the readings were not as clear-cut as engineers would like.

The tests will determine whether the cap can remain sealed over the leak or BP will have to return to a containment system.

Engineers had hoped to register readings of up to 8,000-9,000 pounds per square inch (psi), a high reading that would mean the well is still intact and there is no seepage.

But the reading Saturday, around 6,745 psi, was inconclusive.

"We could have integrity or we could not have integrity between the 6,000 or 7,500 psi" range, Wells said, though he sounded a note of cautious optimism.

"The fact that the pressure continues to rise is giving us more and more confidence as we are getting through the test."

The tests were expected to be completed in around 48 hours, ending on Saturday afternoon, but Wells said they could now continue beyond that point.

"The longer the test goes, the more confidence we have in it," he said.

If the tests prove inconclusive, or show that there may be damage to the wellbore, BP could return to a containment system that captures crude and siphons it up to waiting vessels on the sea surface.

That would see oil flowing back into the sea once again, at least temporarily, as the pressure in the well is lowered and the new system set up.

On Friday, US President Barack Obama said the halt to the oil flow was "good news."

But he cautioned a final solution would not come before mid-August, when the first of two relief wells is completed, allowing the injection of heavy drilling mud into the bottom of the leaking well, which will then be plugged with cement.

"It is important that we don't get ahead of ourselves," Obama said, acknowledging there was still "an enormous amount of work to do" to restore the Gulf region after the worst oil spill in US history.

A video feed that has for weeks shown clouds of oil gushing forth at an estimated rate of 35,000-60,000 barrels a day, showed nothing but a white cap and underwater robots on Saturday morning.

The halt, however temporary, of the leak provided a glimmer of hope that the disastrous spill could soon be over, allowing efforts to turn to the grim job of cleaning up hundreds of miles (kilometers) of contaminated shoreline.

"I was jumping up and down for a while when I saw it was capped," said O'Neil Sevin, who runs a bayou-side shop selling bait, seafood, beer, tackle and snacks to recreational fishermen in Chauvin, Louisiana.

Oil has washed up on the coasts of all five Gulf states -- Texas, Louisiana, Mississippi, Alabama and Florida -- since the spill began April 22, two days after an explosion aboard the BP-leased Deepwater Horizon platform, which killed 11 workers and sank the rig.

The International Energy Agency has calculated there are between 2.3 million and 4.5 million barrels of crude sloshing around in the sea.

A giant skimming vessel, the "A Whale," which officials had hoped would scoop up huge quantities of spilled crude was only able to collect "negligible" amounts during testing and will not be deployed, officials said Friday.

Gulf residents, who are heavily dependent on the fishing and tourism industries have seen their livelihoods ravaged, and the complicated and expensive clean-up process is likely to take years.

BP has so far spent at least 3.5 billion dollars dealing with the spill, and compensation claims could eventually cost 10 times that amount, with BP agreeing to set up a 20-billion-dollar fund to pay damages.