Failsafe control system for a subsurface safety valve
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
E21B-034/10
출원번호
US-0144121
(1998-08-31)
발명자
/ 주소
Beall Clifford H.
출원인 / 주소
Baker Hughes Incorporated
대리인 / 주소
Duane, Morris & Heckscher LLP
인용정보
피인용 횟수 :
23인용 특허 :
12
초록▼
An improved control system, particularly useful for SSVs, is disclosed. The control system has an operating piston which acts on a flow tube to move a flapper to an open position. The flapper is spring-loaded to close when the flow tube moves up. A return spring acts on the piston to lift the flow t
An improved control system, particularly useful for SSVs, is disclosed. The control system has an operating piston which acts on a flow tube to move a flapper to an open position. The flapper is spring-loaded to close when the flow tube moves up. A return spring acts on the piston to lift the flow tube to allow the flapper to close. The operating piston is exposed to a control line from the surface as well as to a bypass piston. Opposing the hydrostatic forces of the control line is a pressurized chamber with a pressure in excess of the hydrostatic pressure. A secondary chamber acts on one side of the equalizing piston and is pressurized to a pressure less than the anticipated hydrostatic pressure in the control line. The system, including the operating piston, is configured so that when leakage occurs into or out of the control system in many places, the SSV will fail toward its failsafe closed position.
대표청구항▼
[ What is claimed:] [1.] A control system for a downhole valve to place a valve member assembly mounted therein in an open and closed position, comprising:an assembly of an actuating piston mounted in a housing with at least one seal, said assembly is operably connected to the valve member assemblys
[ What is claimed:] [1.] A control system for a downhole valve to place a valve member assembly mounted therein in an open and closed position, comprising:an assembly of an actuating piston mounted in a housing with at least one seal, said assembly is operably connected to the valve member assemblysaid actuating piston having a first end in said housing in fluid communication to a pressure source;a primary pressure reservoir in communication with a second end of said actuating piston in said housing such that pressure in said primary pressure reservoir acts against existing hydrostatic pressure on said first end of said actuating piston and applied pressure from said pressure source;a pressure-equalizing mechanism in fluid communication with said pressure source and said second end of said actuating piston, said pressure-equalizing mechanism remaining in a closed position during shifting of said actuating piston with pressure applied or removed from said pressure source;said pressure-equalizing mechanism shifting to an open position upon failure of said at least one seal on said actuating piston. [15.] In a subsurface tubing safety valve control system, having an actuating piston and related housing and seals and operably connected to a flow tube which moves a closer mechanism, said actuating piston comprising a return spring and having a first end exposed to pressure from a pressure source and a second end exposed to pressure in a primary pressure reservoir, said seals on said actuating piston isolating tubing pressure from the control system, the improvement comprising:a bypass from said control line to a location in fluid communication with said second side of said piston and the pressure exerted thereon by said primary pressure reservoir, said bypass path running externally of said piston; anda normally closed valve in said bypass path when application and removal of said pressure source moves said actuating piston. The control system of claim 15, wherein:said valve further comprises a piston valve, said piston valve shiftable to an open position to equalize said pressure source on opposed ends of said actuating piston, and once shifted to open, stays open to preclude movement of said actuating piston with said pressure source. In a subsurface tubing safety valve control system, having an actuating piston and related housing and seals and operably connected to a flow tube which moves a closer mechanism, said actuating piston comprising a return spring and having a first end exposed to pressure from a pressure source and a second end exposed to pressure in a primary pressure reservoir, said seals on said actuating piston isolating tubing pressure from the control system, the improvement comprising:a bypass from said control line to a location in fluid communication with said second side of said piston and the pressure exerted thereon by said primary pressure reservoir;a normally closed valve in said bypass path when application and removal of said pressure source moves said actuating piston; andfailure of any one of said seals in said housing for said actuating piston will cause said piston valve to shift to its said open position. The control system of claim 17, further comprising:a secondary pressure reservoir acting on said piston valve in opposition to pressure from said primary pressure reservoir such that upon loss of a predetermined amount of pressure from said primary pressure reservoir, pressure in said secondary reservoir shifts said piston valve. The control system of claim 18, wherein:said housing for said actuating piston comprising an opening with a first seal in said housing adjacent said first end, a second seal adjacent said first seal and above said opening in said housing, and a third seal adjacent said second end of said actuating piston below said opening in said housing;a passage through said piston, one end of which extends out of said actuating piston between said first and second seals and the other end extending to said second end of said piston;whereupon leakage past said second seal towards said flow tube, the pressure in said primary pressure reservoir is reduced until at a predetermined level, said piston valve shifts open.
Anderson, David Z.; Welch, Jr., Edward W.; Wagner, Alan N.; Bane, Darren E.; Beall, Clifford H., Control line hydrostatic minimally sensitive control system.
Bane, Darren E.; Anderson, David Z.; Wagner, Alan N.; Beall, Clifford H.; Lake, Gary B., Distortion compensation for rod piston bore in subsurface safety valves.
Bane, Darren E.; Anderson, David Z.; Jackson, Aaron T.; Beall, Clifford H.; Welch, Jr., Edward W.; Wagner, Alan N., Downhole hydraulic control system with failsafe features.
Bane, Darren E.; Jennings, Steven L.; Anderson, David Z.; Rosenblatt, Steve, Method of using a charged chamber pressure transmitter for subsurface safety valves.
Anderson, David Z.; Bane, Darren E.; Wagner, Alan N.; Gunnells, John E.; Coghill, Anthony S.; Carney, Allen P.; Brown, Barry Lee; Smith, Troy L.; Johnson, Jeremy R., Switching apparatus between independent control systems for a subsurface safety valve.
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