Crews to start plugging oil well

Engineers are preparing to launch a so-called static kill as early as this evening, shoving mud and perhaps cement into the blown-out well to make it easier to plug the gusher forever and end the Summer of the Spill.

The effort carries no certainty, and BP engineers still plan to follow it up days later by sending a stream of mud and cement into the bottom of the mile-deep underground reservoir through a relief well they have been digging for months.

But the oil company’s engineers and petroleum experts say it is the clearest path yet to choke the blown-out well and ensure oil can never again erupt from the deep-sea well, which has spewed as much as 184 million gallons since the rig connected to it blew up in April, killing 11 workers.

The past few days have brought some other promise, including more headway on the relief well that has long been the promised panacea and the reopening of some fishing grounds. And despite recent concerns by congressional investigators that BP might have overused potentially harmful chemical dispersants, the developments have the makings for an interesting week.

“It could be the beginning of the end,’’ said Darryl Bourgoyne, director of Petroleum Engineering Research Lab at Louisiana State University.

Crews will slowly pump heavy mud through lines installed last month straight down the throat of the leaky well. If the mud forces the oil back into the massive underground reservoir and scientists are confident the pressure remains stable, then engineers can pump in fresh cement to seal it.

“The only thing that separates the oil from the sea now is the valve. This puts thousands of feet of mud and cement in between,’’ said Eric Smith, associate director of the Tulane Energy Institute. “The idea is to have as many barriers as possible between the ocean and the reservoir. We’re adding an extra level of safety.’’

Officials may then begin the process of choking the underground reservoir feeding the well by pumping mud and then cement down an 18,000-foot relief well. BP officials have long said the process is the only sure way to choke the well for good — plugging up the source of the oil, not just its route to the sea.

The company tried a similar process, called a top kill, to choke the well with mud in May. It failed partly because the mud could not overcome the flow of the oil.

There is reason to hope this time will be different. For one, the oil is no longer freely flowing from the well, thanks to the temporary cap that has contained the gusher for two weeks. That means that engineers will not have to pump in mud with as much force, said Kent Wells, a BP senior vice president.

There is always the risk that the pressure exerted by the mud will rupture the casing holding in the oil and potentially cause an even greater mess, but experts say that is unlikely.

“I can’t imagine it failing,’’ Smith said. “It’s holding pressure and there’s no indication of any loss of fluid from the well. It’s a vanishingly small risk of failure.’’

The whole procedure is still set to be completed by late August, despite a brief evacuation for Tropical Storm Bonnie last week.

And federal officials are downplaying its importance in case of a failure. Retired Coast Guard Admiral Thad Allen, the government’s point man on the recovery effort, said yesterday that “static kill is not the end all, be all.’’

BP has had more than its share of failures experimenting with other ambitious efforts. So if the oil is already contained and the completion of the relief well appears to be just around the corner, why is the company even bothering to attempt the complicated static kill?

One reason is that it should make it easier to finish the relief well, which BP and government officials have long said is the only permanent solution. Crews are also drilling a backup relief well a few thousand feet behind the primary one, which is about 100 feet from its target.

If the static kill is successful, though, Smith said they likely would not have to use as much mud to choke the oil. It is also a good way for BP to hedge its bets in case the relief well takes longer than expected to work, he said.

There is a third reason the company has embraced the static kill: the threat of another violent storm disrupting the cleanup process. Federal officials are hoping to end the oil threat before peak hurricane season, which typically lasts from mid-August to late October.