US Patent 11773687 Single solenoid electro-hydraulic control system to actuate downhole valves

An electro-hydraulic control system for actuating a control valve includes a control module. The control module is coupled to the surface via two hydraulic lines and an electrical power line. The control module uses one of the hydraulic lines as an open line and the other line as a close line. The control module includes a normally closed (NC) solenoid valve (SOV) that is coupled to the electrical power line and may be controlled from the surface to open or close. The opening or closing of the NC SOV in cooperation with hydraulic pressure on an open or close line operates (i.e., closes or opens) the control valve.