Patent ID: 6390206
Filing Date: 2002-05-21
Classification: E21B

Abstract:
A hydrostatic working device for use as at least one of a core sampler and a core penetration test sampler, for sampling of sediments at the bottom of the sea, wherein the working device comprises:an inner tube; an outer cylindrical tube having an upper lead-through and lower lead-through near ends of said inner tube, said lead-throughs having gaskets; a first piston movable in an annulus between the outer tube and the inner tube, said inner tube acting as a piston rod for the first piston; a catcher situated on a suction anchor which counteracts penetration forces; and a choke valve, wherein said first piston and said outer tube define sealed chambers below and above the first piston; wherein a flow velocity into the sealed chamber above the first piston can be regulated by said choke valve; and wherein the sealed chamber below the first piston constitutes a low pressure reservoir.