Oil Spill Events

By Colleen Long and Harry R. Weber/The Associated Press

A summary of events Friday, July 16, Day 87 of the Gulf of Mexico oil spill that began with the April 20 explosion and fire on the drilling rig Deepwater Horizon, owned by Transocean Ltd. and leased by BP PLC, which is in charge of cleanup and containment. The blast killed 11 workers. Since then, oil has been pouring into the Gulf from a blown-out undersea well, though BP said it finally choked off the flow Thursday afternoon.

ENCOURAGED

BP was encouraged early Friday by results from an experimental cap shutting in oil from its busted Gulf of Mexico well, saying everything was holding steady 17 hours into the effort. BP vice president Kent Wells said there was no evidence of a leak in the pipe under the sea floor, one of the main concerns. He said pressure continued to rise inside the tight-fighting cap — a sign that oil was gushing into it, instead of out through any undiscovered cracks, and staying there. Wells said two undersea robots were combing the sea bed, looking for any trace of oil or problems on the floor.

PRESSURE

As of Friday, the pressure was more than 6,700 pounds per square inch, above the minimum they were hoping to see, but not yet in the high range of 8,000 to 9,000 psi they were hoping for. BP vice president Kent Wells said the increase has been steady and consistent with engineering analysis.

RELIEF WELL

Wells said work would resume on one relief well, the oil giant’s more permanent solution to plug the well for good and end one of the nation’s worst environmental catastrophes. That’s also a good sign that things were going well. Engineers had stopped drilling that relief well in case its work could be affected by added pressure on the underground oil from the cap. The relief well is designed to plug the gusher with cement and mud deep underground, where the seal will hold more permanently than any cap on top.

REOPEN THE CAP?

It’s still unclear whether the well cap will need to be reopened to allow oil to leak back after the test. BP finally stopped oil from spewing into the sea Thursday, for the first time since an April 20 explosion on the BP-leased Deepwater Horizon oil rig killed 11 workers and unleashed the spill 5,000 feet beneath the water’s surface.

RELIEF AND DISBELIEF

Many Gulf Coast residents don’t believe it. Some accuse BP of making it up. And even those convinced that the oil leak has finally been stopped are tempered in their relief, aware that their environmental nightmare is far from over. Gulf Coast residents have suffered from months of false starts and dashed hopes, failed “top kills” and abortive “junk shots,” containment domes and “top hats,” as they watched the biggest offshore oil spill in U.S. history foul their shores and eat into their livelihoods.

ABANDONED WELLS

A lead congressional committee investigating the Gulf of Mexico oil spill has broadened its inquiry, now checking if tens of thousands of abandoned oil and gas wells are leaking or even being monitored for leaks. Committee members wrote in a letter Thursday to Interior Secretary Ken Salazar that they were responding to an Associated Press investigation released last week on the 27,000 abandoned wells in the Gulf. The AP reported that the wells are not routinely inspected when plugged or subsequently monitored for leaks.