Balanced line tubing retrievable safety valve

专利名称：Balanced line tubing retrievable safety valve发明人：Rennie L. Dickson,Nam Van Le申请号：US08/980593申请日：19971201公开号：US06003605A公开日：19991221

摘要：A tubing retrievable surface controlled subsurface safety valve 106 is adaptedto be positioned in a well tubing string 102 to control the flow through the tubing string.The safety valve includes an annular housing or body 200 defining a fluid passagewaythrough which fluids and/or gasses may flow to the surface. The safety valve is equippedwith a valve closure member such as flapper 252, positioned in the fluid passageway whichis moveable between an open and closed position. The valve closure member is engagedand actuated by a longitudinally extending operator 242 that engages the valve closuremember 252. In one embodiment, the longitudinally extending operator 242 may be atubular member longitudinally moveable within the valve body. The longitudinallyextending member 242 is operatively coupled to a spring guide 226. A biasing spring 222is positioned in a spring chamber 120 defined by a spring housing 228 and the springguide 226. A spring 256 biases the closure member 252 in the closed position. A balanceline 114 extending from the surface is connected to a balance pressure conduit 118 thatis in fluid communication with the spring chamber 120 to balance the hydrostatic pressurefrom the control line 112. The spring chamber 120 is isolated from well pressure at thetop and bottom therefore the pressure applied to the spring chamber 120 through thebalance pressure line via the balance pressure conduit 118 counteracts the hydrostatic

head of the fluid in the control line or lines, thereby enabling the subsurface safety valve106 to operate at vary depths.

申请人：HALLIBURTON ENERY SERVICES, INC.

代理人：William M. Imwalle,Lawrence R. Youst

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