Control system for a surface controlled subsurface safety valve

摘要

Surface controlled subsurface control valves for use in wells and methods of controlling the same. In one embodiment, a valve includes a valve body, a bore closure assembly, a mechanical linkage, a drive assembly, and a control assembly. The valve body defines a bore for fluid to flow through when the bore closure assembly is in an open position. When the bore closure assembly is in its closed position, the bore closure assembly prevents fluid from flowing through the bore. The mechanical linkage is operatively connected to the bore closure assembly and to the drive assembly. The primary control assembly determines a force to apply to the mechanical linkage based on a present operating condition of the valve and causes the drive assembly to apply the determined force to the mechanical linkage. As a result, the mechanical linkage drives the bore closure assembly.

主权项

1. A method of controlling a surface-controlled subsurface control valve in a subterranean well, the subsurface control valve having a housing defining a bore for fluid flow, a valve element mounted for movement in the bore between open and closed positions, and an electric motor for applying force to the valve element, the method comprising:
sensing a first operating condition of the valve; driving the valve element, with the electric motor, with a first force towards one of the closed or open positions in response to the sensed first operating condition; then sensing a second operating condition of the valve; and driving the valve element, with the electric motor, with a second force, different than the first force, towards the same closed or open position in response to the sensed second operating condition.