Patent ID: 8555988
Filing Date: 2013-10-15
Classification: E21B

Abstract:
1. A downhole oilfield tool assembly, comprising: a mandrel; a valve oriented to block downwards flow through the mandrel in a closed position, wherein the valve comprises: a setting sleeve, a collet mandrel rotatably disposed concentric with the mandrel, and a biasing mechanism, wherein in a first rotational position of the collet mandrel relative to the mandrel, the collet mandrel is locked against rotational motion relative to the setting sleeve and the valve is in an open position, and wherein in a second rotational position of the collet mandrel relative to the mandrel, the biasing mechanism is configured to axially translate a flapper prop and transition the valve to the closed position, wherein the second rotational position is rotationally offset about a longitudinal axis of the collet mandrel from the first rotational position; and a first piston located above the valve and positioned at least partly around an outside of the mandrel, wherein the first piston is configured to develop motive force from a pressure differential between an interior of the mandrel and an exterior of the downhole oilfield tool assembly when the valve is in the closed position.