2,227 psi at the well head...

I had to go back to Scuba Diving Physics and after making a quick call to my PADI SCUBA Instructor to confirm it, Chet helped to refresh some calculations regarding water pressure at depth...

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"We know that water is much heavier than air, so it exerts higher pressures with less volume. A cubic foot of water weighs 62.5 lbs, whereas a cubic foot of air weighs 1/12 lb. Sea water is even heavier - a cubic foot of sea water weighs 64 lbs. To exert 14.7 psi (1 ATM) it takes 50 miles of air, whereas it only takes 33 feet of water to exert the same pressure."

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It is reported that the Deepwater Horizon wellhead is at a depth of about 5,000 feet saltwater.

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5,000 ft-sw divide by 33 and multiply by 1 atmosphere (14.7 lbs) is equal to

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2,215 lbs per square inch

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of pressure at the wellhead. If you were to push a single golfball out of a pipe at that depth you would need 2,215+ psi just to push it out the end of the pipe...

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