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A lock open mechanism for downhole safety valve of the type having a valve head movable downwardly from a closed to an open position relative to the bore of a well conduit. The housing of the safety valve is provided with a first downwardly facing locking shoulder above the valve head. The upper por

A lock open mechanism for downhole safety valve of the type having a valve head movable downwardly from a closed to an open position relative to the bore of a well conduit. The housing of the safety valve is provided with a first downwardly facing locking shoulder above the valve head. The upper portion of the safety valve housing is provided with a no-go shoulder and above that a second downwardly facing latching shoulder. A mandrel has a tubular locking body shearably secured to its lower end which locking body is abutable with the valve head. The valve head is displaced downwardly by incremental jar produced downward movements of the mandrel until a locking collet carried on the locking body engages the first downwardly facing locking shoulder. The second downwardly facing latching shoulder absorbs upward forces exerted on the mandrel and the locking assemblage through engagement by a latching collet mounted on an intermediate housing which is carried into the well by a shearable connection which is released when the mandrel reaches its run-in position. After the locking collet is engaged, the latching collet heads are freed for disengagement from the valve housing, permitting the mandrel and the intermediate housing assemblage to be retrieved from the well.

대표청구항 ▼

For use in a downhole safety valve for a subterranean well conduit having an axially shiftable valve member movable downwardly between a closed and an open position relative to the conduit bore and biased to said closed position; said safety valve including a tubular housing assemblage defining an u

For use in a downhole safety valve for a subterranean well conduit having an axially shiftable valve member movable downwardly between a closed and an open position relative to the conduit bore and biased to said closed position; said safety valve including a tubular housing assemblage defining an upwardly facing no-go shoulder in its upper end and a downwardly facing locking shoulder in its lower end above said valve member; a wireline operable lock open mechanism comprising: a central mandrel having means on its upper end for connection to a wireline equipped with jars; a tubular locking assemblage shearably secured to the bottom end of said central mandrel and abuttingly engagable with said valve member; an intermediate tubular housing assemblage surrounding the upper portions of said mandrel and insertable in the bore of said valve housing assemblage with said mandrel; shearable means connecting said mandrel assemblage to said intermediate housing assemblage for run-in; downwardly facing no-go shoulder means on the upper end of said intermediate housing assemblage; said downwardly facing no-go shoulder means being body lock means engagable with said upwardly facing no-go shoulder to position said tubular locking assembly upwardly adjacent to said valve member; intermediate housing assemblage and said mandrel assemblage to permit only downward jar produced movement of said mandrel assemblage relative to said intermediate housing assemblage after shearing said shearable means, thereby moving said tubular locking assemblage and said valve member incrementally downwardly to said open position; and lock means on said locking assemblage engagable with said downwardly facing locking shoulder, thereby securing said valve member in an open position and permitting an upward force on said mandrel to shearably detach said mandrel from said tubular locking assemblage.