(19)
(11)EP 2 096 254 A3

(12)EUROPEAN PATENT APPLICATION

(88)Date of publication A3:
30.11.2011 Bulletin 2011/48

(43)Date of publication A2:
02.09.2009 Bulletin 2009/36

(21)Application number: 09153547.6

(22)Date of filing:  24.02.2009
(51)International Patent Classification (IPC): 
E21B 23/04(2006.01)
F16K 31/06(2006.01)
E21B 34/10(2006.01)
F15B 21/00(2006.01)
(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK TR
Designated Extension States:
AL BA RS

(30)Priority: 29.02.2008 US 40110

(71)Applicant: HALLIBURTON ENERGY SERVICES, INC.
Dallas, TX 75381-9052 (US)

(72)Inventors:
  • Vick, Jr., James D.
    Dallas, TX 75205 (US)
  • Williamson, Jimmie R.
    Carrollton, TX 75007 (US)

(74)Representative: Bennett, Adrian Robert J. 
A.A. Thornton & Co. Mechanical 235 High Holborn
London WC1V 7LE
London WC1V 7LE (GB)

  


(54)Control system for an annulus balanced subsurface safety valve


(57) A control system (10) for an annulus balanced subsurface safety valve (12). A system for operating a safety valve in a well includes a piston (38) of the safety valve being responsive to displace due to a pressure differential between chambers exposed to the piston; and a valve controller (24) which alternately exposes at least one of the chambers to pressure in an annulus surrounding the safety valve, and to pressure greater than that in the annulus. A method of operating a safety valve in a well includes the steps of: opening the safety valve by biasing a piston of the safety valve to displace in response to a pressure differential between a chamber exposed to pressure greater than well pressure, and another chamber exposed to well pressure; and closing the safety valve by exposing both of the chambers to the well pressure.







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