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Pressure control apparatus and method

  • US 7,296,624 B2
  • Filed: 01/18/2005
  • Issued: 11/20/2007
  • Est. Priority Date: 05/21/2003
  • Status: Active Grant
First Claim
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1. An apparatus for controlling the pressure in an isolated lower wellbore annulus while gravel packing, the isolated lower wellbore annulus being defined by a conduit sealably positioned within an isolated lower wellbore segment, the apparatus comprising:

  • a plurality of valves carried by the conduit at discrete locations for selectively admitting fluid from the isolated lower annulus into the conduit at the discrete locations; and

    a pressure-sensitive device carried by the conduit independently of the valves for sensing the pressure within the isolated lower annulus while gravel packing, and for actuating one or more of the valves when the sensed pressure corresponds to one or more threshold pressure conditions so as to admit fluid from the isolated lower annulus into the conduit and thereby control the pressure within the isolated lower annulus while gravel packing, wherein each of the valves comprises;

    a valve body carried within the conduit, the valve body being equipped with a first port for admitting fluid from the isolated lower annulus to the conduit; and

    a piston slidably disposed in a chamber of the valve body and movable from a position closing the first port to a position opening the first port upon actuation of the piston by the pressure-sensitive device, each valve further comprising a check valve carried in the first port to ensure fluid flows through the first port in one direction;

    from the isolated lower annulus to the conduit, the check valve comprising a flapper valve having one or more pivotally mounted plates.

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