Patent ID: 8978766
Filing Date: 2015-03-17
Classification: E21B,Y10T

Abstract:
1. A temperature compensated accumulator comprising: a generally cylindrical housing having a first longitudinal end and a second longitudinal end, each longitudinal and having a port therein, the housing divided into three sections, including a centrally sealable pressure relief chamber, by two longitudinally spaced apart bulkheads; a first piston disposed in the housing on one side of a first of the two bulkheads, the first piston separating a hydraulic fluid chamber and a gas precharge pressure chamber; a second piston disposed in the housing on one side of a second of the two bulkheads, the second piston separating an ambient pressure chamber and an atmospheric chamber; a connecting rod disposed between the first and second pistons; and a pressure relief valve and a check valve in pressure communication between the gas precharge pressure chamber and the pressure relief chamber, the pressure relief chamber defined between the first bulkhead and the second bulkhead, the pressure relief chamber including a longitudinally movable pressure barrier responsive to downhole temperature variations, the pressure relief valve set to a preselected value within a range of pressure safely containable by the housing, the pressure barrier engageable with a stop feature on the connecting rod such that an increase in pressure of the ambient pressure chamber compresses gas discharged into the pressure relief chamber back into the gas precharge pressure chamber through the check valve.