초록 ▼

A control system for the operation of the subsurface safety valve is disclosed. The control system uses a pressurized gas chamber, as well as a shuttle valve which connects to the main fluid pressure supply from the surface. The shuttle valve is connected to the gaseous chamber as well as to a barri

A control system for the operation of the subsurface safety valve is disclosed. The control system uses a pressurized gas chamber, as well as a shuttle valve which connects to the main fluid pressure supply from the surface. The shuttle valve is connected to the gaseous chamber as well as to a barrier piston. As a result of the arrangement, leakages between the downstream side of the operating piston and the shuttle valve result in a reestablishment of the pressure balance on the operating system which allows the subsurface safety valve to close. Additionally, in the event of loss of gaseous pressure, the same pressure-balancing effect occurs on the operating piston, which allows the subsurface safety valve to go to a closed position. The configuration of the control system, which includes a gaseous chamber, allows for disconnection of the hydraulic fluid supply before the predetermined depth is reached to facilitate the connection of a tubing hanger.

대표청구항 ▼

[ We claim:] [1.] A control system for a subsurface safety valve, comprising:a subsurface safety valve;a biased main piston operably connected to said subsurface safety valve through an opening in a main cylinder in which said main piston is reciprocally mounted, said main cylinder having an upper c

[ We claim:] [1.] A control system for a subsurface safety valve, comprising:a subsurface safety valve;a biased main piston operably connected to said subsurface safety valve through an opening in a main cylinder in which said main piston is reciprocally mounted, said main cylinder having an upper connection and a lower connection;a control valve mounted in parallel to said main cylinder to selectively prevent pressure applied at said upper connection from being applied at said lower connection on said main cylinder;at least one compensating piston in at least one compensating cylinder, said compensating piston being displaced responsive to movement of said main piston between said upper and lower connections thereof;said compensating cylinder having a first connection in fluid communication with a pressurized fluid reservoir on the opposite side of said compensating piston from said main cylinder;said pressurized fluid reservoir operably connected to said control valve to counteract hydrostatic forces of a control fluid column from the surface to said upper connection of said main cylinder.