Patent ID: 7296624
Filing Date: 2007-11-20
Classification: E21B

Abstract:
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: