Deep set subsurface safety system
A subsurface safety valve is operable to close a fluid flow path by virtue of an axially movable flow sleeve. The valve includes a recockable linear actuator and a latch mechanism so that the valve can be moved from an open to a closed position as a result of axial movement of the flow sleeve without overcoming the pressure head and frictional forces currently encountered in conventional safety valves.
1. A safety valve comprising:
a) a body,
b) a flow sleeve positioned within the body and axially movable,
c) a valve element pivotably mounted within the body between an open and closed position,
d) a recockable actuator within the body for moving the flow sleeve in an axial direction, and disengaging from the flow sleeve when the valve is in the open position,
e) a latching mechanism for locking and unlocking the flow sleeve in a given position; and
f) wherein the latching mechanism comprises an annular groove on an outside surface of the flow sleeve and a split ring formed of a shape memory alloy that contracts partially into the groove when activated.
2. A safety valve as claimed in claim 1 wherein the recockable actuator comprises a motorized electric linear actuator.
3. A safety valve as claimed in claim 1 wherein the recockable actuator comprises a shape memory alloy linear actuator.
4. A safety valve as claimed in claim 1 wherein the flow sleeve includes a shoulder, and a spring captured between the shoulder and a second shoulder located within the valve body.
5. A safety valve as claimed in claim 1 wherein the split ring is positioned within the valve body.