[Ben Lahnger]

While Transocean and British Petroleum still struggle with efforts to stop the flow of oil from the broken pipe in the Gulf of Mexico, the following article about a similar problem off the shore of Australia gives us an idea about how long it may take to fix this thing,

Relief Well Was Used to Halt Australian Spill

While BP tries various short-term efforts to plug a leaking oil well in the Gulf of Mexico, the company is preparing to drill a relief well as a backup plan. BP hopes to drill that well diagonally to intersect the original one below the seabed and then flood it with mud and concrete to stop the uncontrolled flow.

Although the idea sounds simple, the experience with a similar spill last year near Australia shows just how difficult it can be to execute the maneuver.

“It’s like finding a needle in a haystack,” said Rachel Siewert, an Australian senator who is a member of the country’s opposition Greens Party and is critical of the oil industry.

The Australian accident, known as the Montara spill, began Aug. 21 with a blowout of high-pressure oil similar to the one in the gulf. With the well spewing 17,000 to 85,000 gallons per day, precious weeks passed before the relief wells were started. When efforts got under way, the first four attempts — drilled on Oct. 6, 13, 17 and 24 — missed the original well.

A fifth attempt finally intersected the original on Nov. 1, and about 3,400 barrels of heavy mud were pumped through the relief well into the base of the original well. The spewing oil finally stopped Nov. 3 — more than 10 weeks after the original explosion.

BP intends to drill a similar relief well close to the site where the Deepwater Horizon drilling rig blew up and sank in the gulf nearly two weeks ago. The company says the well could take months to complete. In the meantime, the well continues to leak 210,000 gallons of oil a day, according to the latest official estimates.

The Montara accident resembled the Gulf of Mexico accident in that both started with problems in the well itself, and it proved very hard to stop without resorting to further underground drilling, said Elmer P. Danenberger III, who was the top American regulator of offshore oil drilling until his retirement on Jan. 2.

“There are clearly some similarities,” Mr. Danenberger said.

Drilling the relief well proved tricky in the Montara spill, which was located in Australian waters in the Timor Sea, between northwest Australia and Indonesia.

The drilling team was trying to hit a well casing less than 10 inches in diameter at a depth 1.6 miles below the seabed, according to testimony this spring before an Australian government commission of inquiry.

The BP well has an even skinnier casing, reportedly measuring seven inches in diameter.

(more of this article at the link in the headline above)