Water sampling and disposal apparatus for an offshore operating site

Claim 1

The combination with a marine structure positioned at an offshore body of water and being communicated with a source of process gas resulting from a hydrocarbon producing operation, which operation further yields a supply of an immiscible dispersion liquid comprising waste water and hydrocarbon liquid, of an upstanding elongated disposal caisson communicated with said immiscible dispersion liquid supply for effecting a gravity separation of the water component thereof from the hydrocarbon liquid, and a discharge port positioned at the disposal caisson lower end, a pump positioned at the caisson lower end and including means forming coaxially arranged power chamber and collecting chamber, a piston slidably received in reciprocal movement between advanced and retracted positions in each of said respective power and collecting chambers, and being connected by a common piston rod, means communicating said power chamber with a source of a pressurized gas whereby to displace piston in said power chamber when an amount of said pressurized gas is introduced thereto, a passaged panel means disposed intermediate the respective power and collecting chambers to slidably register said piston rod therein, and to communicate the respective chambers one with the other, biasing means engaging at least one of said pistons to urge the same into a retracted position at one end of the respective power and collecting chambers, venting means communicating the power chamber with said immiscible dispersion liquid to permit a flow of the said liquid through the respective chambers and through said passaged panel during reciprocal movement of the piston through the respective chambers, flow control means including, a first valved passage communicating the collecting chamber with liquid at the caisson lower end and being operable to permit a stream of said liquid to be drawn into said collecting chamber when the piston is moved to the retracted position, and a second valved passage being operable to direct said stream of liquid from said collecting chamber during the piston discharge stroke, and conduit means communicated with said second valved passage and extending to the water's surface whereby said stream of liquid can be delivered to the latter.