Monday, June 14, 2010

Relief Wells

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A drilling rig drills a relief well or second well to intersect the original, flowing well as deeply as possible. A specialized heavy liquid is then pumped into the flowing well to bring it under control. This liquid is denser than oil and so exerts pressure (known as hydrostatic pressure) to stem the flow of oil.

Once the flow is stopped, the well can be returned to a safe condition. Drilling a well of this nature presents many technical challenges to ensure that the flowing well is intersected in the right position and that the fluid pumping operations are effective.

The Obama administration insisted that BP drill a second relief well in case there were problems with the first well. It is anticipated that the wells will be completed sometime in August or September. Relief wells of this type usually work, but critics state that there is no guarantee that the relief wells will work. The Center is recommending that two relief wells should be included with drilling at the 33 pending deepwater wells currently under a 6-month stop-work moratorium. The moratorium should be lifted. The Center opposes expanded offshore drilling. (BP)

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