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U.S. Department of Energy
Office of Scientific and Technical Information

Downhole safety valve operable by differential pressure

Patent ·
OSTI ID:5394242
This patent describes an oil well downhole safety valve operable by downhole annulus pressure, comprising: a. a tool body having a continuous (well) wall defining a longitudinal flow bore for conveying liquid, and adapted to travel through a well annulus as part of a work string; b. a valve body slideably mounted within the tool longitudinal flow bore; c. seal means carried by the valve body for forming a seal between the valve body and the continuous wall of the tool body; d. a valving member carried by the valve body for travel therewith and movable between open flow and closed flow positions for valving the flow bore; e. drive means operative by annulus pressure for moving the valving member between open flow and closed flow positions and comprising a pair of opposing pistons attached to the valve body with drive surfaces of differing surface areas; and f. a pair of openings through the tool body and positioned respectively above and below the pair of pistons, for allowing annulus pressure to communicate with the flow bore and with the piston drive surfaces so that annulus pressure simultaneously acting upon the piston drive surfaces can move the valving member.
Assignee:
NOV; NOV-88-001173; EDB-88-071639
Patent Number(s):
US 4714116
OSTI ID:
5394242
Country of Publication:
United States
Language:
English