Subsurface safety valve actuator

A subsurface relief valve actuation system in a well conduit includes a relief valve, a piston assembly, a motor, a pump, a spring, a reservoir, a first valve and a second valve configured to provide a pressure in a chamber of the piston assembly to drive the relief valve to an open position, maintain a pressure in the chamber to maintain the relief valve in the open position, and provide a pressure in the chamber to drive the relief valve to an open position. Pressure in the chamber is released via a first hydraulic release path and/or a second hydraulic release path extending through the first valve and the second valve, respectively, between the chamber and the reservoir, and the first hydraulic release path and the second hydraulic release path are independent of each other, thus, when there is a failure in one of the first or second release paths, pressure in the chamber that holds the relief valve in the open position may be released via the other of the first or second hydraulic release paths. 本发明涉及一种井