SURFACE CONTROLLED DOWNHOLE VALVE WITH SUPPLEMENTAL SPRING CLOSING FORCE FOR ULTRA DEEP WELLS

摘要

Apparatus for the activation of a deep set surface controlled subsurface valve such as a SCSSV or a gas vent valve by means of hydraulic pressure applied to an externally mounted control line includes the use of supplemental forces to assist the normal closing force to close the valve. A valve body with a longitudinal bore for fluid flow through, a bore closure member such as a flapper or sleeve, a hydraulic piston to provide for valve opening when pressure is applied to the control line and a plurality of spring assemblies are provided. The spring closure mechanism(s) enable the valve to be set and safely operate at very deep setting depths. Alternatively, magnets of opposite polarity may be positioned in the valve, one of which is attached to an axially movable flow tube located within the valve. The magnetic attraction force increases the total force available to overcome the hydraulic pressure on the piston.