Engineers believe relief wells should work

Last week, I heard rumors that the relief wells that are being drilled to stop oil spewing from the Deepwater Horizon well might not work.

The email discussed a similar accident off of Australia, known as the Montara spill, that began Aug. 21, 2009 and leaked as much as 85,000 gallons per day for four months. The first four attempts – drilled on Oct. 6, 13, 17 and 24 – failed and missed the original well.

Drilling the relief well in the Timor Sea was difficult because the well casing was about 10 inches in diameter at a depth of 1.6 miles below the seabed.

Deepwater Horizon’s well casing is around 7 inches in diameter and is two to three miles below the seabed. Also the Montara drilling platform was operating in water that was 250 feet deep, while the Deepwater Horizon drilling rig was in water 5,000 feet deep.

The email ended with this doomsday warning: “There is no guarantee that BP will EVER hit the well bore with their relief well, they are warning the public to be prepared for the hopefully small, but certainly real possibility that this oil plume could leak at its present rate or even more. . . . . FOR YEARS!”

I began scrambling looking for petroleum experts to see if this was true. Fortunately, the two college professors, from the University of Alabama and Louisiana State University, that I found believed the relief wells would work.

“The relief well appears to be the only long-term solution for capping the Deepwater Horizon well that is spewing millions of gallons of crude in the Gulf of Mexico,” said Peter Clark, Associate Professor of Mineral Engineering, University of Alabama.

“This is a small wellbore,” Clark said. “Usually they drill bigger holes, seldom more than about 15 or 20 inches. Usually they’re bigger because they drill multiple holes out of the same wellbore. That will be eight or nine wells off of the same production platform.

“This one doesn’t appear to have been this way. One good thing about this well is that its have very well-characterized formation. The well off of Australia, in though it was in shallower water, was a wildcat. It was an exploratory well. The odds are they will be able to hit this one better than the one in Timor, but is it 100 percent or two percent better? I don’t know.”

Ted Bourgoyne, professor emeritus of petroleum engineering at Louisiana State University, said that hitting the Deepwater Horizon well is like “finding a needle in a haystack,” but he was optimistic about the success of the relief wells.

“They have directional surveys and GPS to help them locate the well casing.”
Clark agreed. “The technology is there. They have the history of the well so they should be able to hit it without too much problems. They can steer these things amazingly accurately. The downhole technologies these days is just amazing.”

He said, “Drilling is probably the only option if they can’t do a top kill. They can back off and try again if they miss the wellbore. They don’t have to start from the surface again. They can keep stabbing at it until they finally hit it.

I asked Clark and Bourgoyne about the so-called “nuclear option,” which involves denoting a nuclear bomb over the leak to close it.

“That is crazy,” Bourgoyne said. “You could wind up with more fractures in the seabed and make the problem worse.”

Clark brought the failed Project Gas Buggy. “Years ago somebody decided that the way to get gas from tight reservoirs was to dig a hole, a plant a nuclear device at the bottom of the hole and denote it,” Clark said. “Then wait the prerequisite number of years for the gas to lose enough of its radioactivity that you put in a pipeline.

“Essentially what they did is blow a big glass bubble. The trouble with the nuclear option is that there is no control. You don’t know what is going to happen. You just might blow the thing up and open that pipe wide open, then you have a hard time stopping it.”

Clark added, “I would say that’s beyond the last resort. There so much crap floating around this. It’s totally the internet, too many people writing stuff that don’t have a clue.”

Clark had his own theory on the April explosion at Deepwater Horizon that sank the platform and killed 11 men:

“I finally got a hold of the driller’s log. It appears as though, more and more, that the cement didn’t set and that’s what caused the problem. They tested the float equipment, a one-way valve. When landed the bottom plug and then landed the top plug, they tested the float and the float held. What that means is that they opened the valve and it did not float back. At one point in time, the float had held. Then they started pressure testing it and when they did, the float must have opened. When the float opened, it must have jammed – that’s pure speculation. Once it was jammed open anything could have gotten back into the well.

“When the pressure went negative – “That was a little weird, but that was the weight on the bit. What that indicates is there was an upward flow pushing the bit up. You’ve got some neutral weight on the bit. …That was disturbing because it indicated there was flow.

“It was a series of unfortunate events. Anyone of which had it not gone wrong stopped the whole process. The dots came together in an unfortunate way.”