Patent ID: 8464795

Claim:
An annulus isolation valve, comprising: a valve actuation bore having a first longitudinal axis; a flow passage capable of providing fluid communication between an upper annulus and a lower annulus, the flow passage comprising a first flow path and a portion of the valve actuation bore, the first flow path having a second longitudinal axis that is different from the first longitudinal axis; a plug gate positioned in the valve actuation bore having a first opening, a second opening positioned below the first opening, and a gate flow path between the first and second openings that is a portion of the flow passage, the plug gate capable of moving between an open position and a closed position, the plug gate in the open position being configured to allow fluid communication between the upper annulus and the lower annulus, and the plug gate in the closed position being configured to block fluid communication between the upper annulus and the lower annulus; a biasing mechanism positioned in the valve actuation bore, the biasing mechanism being physically coupled to the plug gate so that an actuation force applied to the biasing mechanism is capable of moving the plug gate into the open position, the biasing mechanism further being capable of forcing the plug gate into the closed position when the actuation force is not applied; and wherein a transverse flow path fluidly connects the first flow path and the valve actuation bore, the first opening of the plug gate fluidly connects with the transverse flow path, and the second opening of the plug gate is adjacent to and fluidly connects with the lower annulus when the plug gate is in the open position.