Patent ID: 9297232
Filing Date: 2016-03-29
CPC Classification: E21B

Claim Text:
1. An apparatus for isolating a first zone from a second zone in a subterranean wellbore, the apparatus comprising: an outer tubular and an inner tubular disposed within the outer tubular forming a substantially annular flow path therebetween that is in fluid communication with the first zone, the inner tubular defining a central flow path therein that is in fluid communication with the second zone; a sleeve having at least one seal disposed on an inner surface thereof, the sleeve positioned in the annular flow path to control fluid flow therethrough, the sleeve axially movable relative to the outer tubular and the inner tubular between a closed position wherein the seal engages an outer surface of the inner tubular and an open position wherein the seal engages an outer surface of the outer tubular; and a mandrel slidably disposed within the inner tubular and coupled to the sleeve, the mandrel operable to shift the sleeve between the open position and the closed position responsive to changes in pressure within the central flow path.