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hey guys an engineer would love some help to get an explanation, Thank you.

  • 22-07-2011 2:30pm
    #1
    Mahony
    Registered Users, Registered Users 2 Posts: 43 ✭


    Problem:
    Drilling in London and high pressure Nitrogen gas pockets are hit killing two workers due to lack of ventilation.



    Background and proposed theory:
    Underneath London in the 1940s the water table was lowered underneath an impermeable layer of clay.
    This created a vacuum in certain areas
    Due to the vacuum the water cavitated
    Air came out of the water and formed above the water and below the clay.
    Iron present in the clay oxidised causing the removal of Oxygen in this air and resulted in Nitrogen rich air
    Water table increased (due to less demand officially) and resulted in the Nitrogen under high pressure.

    Question:
    Does this theory make sense to scientists?

    Thanks for your help regardless I really appreciate it

    Mahony


Comments

  • #2
    Morbert
    Registered Users, Registered Users 2 Posts: 3,457 ✭✭✭Morbert


    Wouldn't the water rise to fill the vacuum?

    http://www.youtube.com/watch?v=_3YArPbmjsY&NR=1


  • #3
    krd
    Banned (with Prison Access) Posts: 3,455 ✭✭✭krd


    They're gas pockets.

    Over enough time, through oxidation and bacterial activity, all the oxygen could be sucked out of the air in these pockets - leaving something like a huge pocket of nitrogen. Water normally carries excess oxygen (stuff that's not used up in H2O). Given the right conditions, there could be a build up of nitrogen. There could also be methane and carbon dioxide pockets - these can and do kill sewer workers and miners.

    Those London sewers have some very big spaces. They have vaulted ceilings. The belief being they could trap the miasma, or bad air (mal aria) in the sewers.

    And what could start out as a water filled cavity, could over time become a gas pocket. As gases like nitrogen, or carbon dioxide were leeched from the water or by bacterial activity.

    If you were drilling, and you hit a gas pocket - you could be asphyxiated in the gas plume.


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