Safety valve hydraulically operated by telescopic drill stem movement

Claim 2

Safety valve apparatus adapted for closing a well pipe against upward flow of fluids therethrough, comprising: tubular telescoping members defining a flow passage and movable between extended and contracted relative positions; full-opening valve means for opening and closing said flow passage, said valve means including a valve seat surrounding said flow passage and a valve element adapted to close upwardly against said valve seat; and actuator means including oppositely moving parts for opening said valve means in response to extension of said members and for closing said valve means in response to contraction of said members.

Claim 3

The apparatus of claim 1 wherein at least one of said parts is sealingly slidable with respect to one of said members to define an enclosed chamber containing hydraulic fluid, movement of the other of said parts in one longitudinal direction functioning to displace fluid in said chamber and cause movement of said one part in the opposite longitudinal direction.

Claim 4

The apparatus of claim 2 wherein said one part is operatively coupled to said valve means for actuating the same in response to such longitudinal movement, and said other part is arranged to be moved by the other of said members in response to contraction of said members.

Claim 5

The apparatus of claim 1 wherein said oppositely movable parts are sealingly slidable with respect to each other and one of said members and together with said one member define an enclosed chamber containing hydraulic fluid, longitudinal movement in one direction of one of said parts with respect to said one member displacing said hydraulic fluid and causing movement of the other of said parts with respect to said one member in the opposite longitudinal direction.

Claim 6

The apparatus of claim 4 wherein said one part includes a portion movable into and out of said chamber to effect displacement of said hydraulic fluid.

Claim 7

The apparatus of claim 1 wherein said valve means includes a flapper valve element movable between a closed position transverse to said flow passage and an open position to the side of said flow passage.

Claim 8

The apparatus of claim 1 further including means responsive to longitudinal movement of said actuator means for equalizing the pressures of fluids above and below said valve means prior to opening of said valve means.

Claim 9

The apparatus of claim 1 further including piston and cylinder means on said members for balancing out and cancelling the net effect on said members of changes in the pressure of fluids in said passage through said members.

Claim 10

The apparatus of claim 8 further including coengaged spline means on said members for preventing relative rotation thereof.

Claim 11

Safety valve apparatus for use in a well, comprising: an upper inner member telescopically disposed within a lower outer member and movable with respect thereto between extended and contracted relative positions, said members defining a flow passage extending longitudinally therethrough; full-opening valve means mounted on said outer member for opening and closing said flow passage; hydraulically operated first valve actuator means movable upwardly in said outer member for enabling closure of said valve means and downwardly in said outer member for causing opening of said valve means; chamber means containing hydraulic fluid cooperable with said first actuator means for moving said first actuator means in response to displacement of hydraulic fluid within said chamber means; and force responsive second valve actuator means movable downwardly in said outer member for displacing hydraulic fluid in said chamber means and causing upward movement of said first valve actuator means in response to telescoping relative movement of said members to said contracted position.

Claim 12

Safety valve apparatus for use in a well, comprising: an upper inner member telescopically disposed within a lower outer member and movable with respect thereto between extended and contracted relative positions, said members defining a flow passage extending longitudinally therethrough; full-opening valve means mounted on said outer member for opening and closing said flow passage; hydraulically operated first valve actuator means movable upwardly in said outer member for enabling closure of said valve means and downwardly in said outer member for causing opening of said valve means; chamber means containing hydraulic fluid cooperable with said first actuator means for moving said first actuator means in response to displacement of hydraulic fluid within said chamber means; and force responsive second valve actuator means movable downwardly in said outer member for displacing hydraulic fluid in said chamber means and causing upward movement of said first valve actuator means in response to telescoping relative movement of said members to said contracted position.

Claim 13

The apparatus of claim 10 further including spring means reacting between said first valve actuator means and said outer member for urging said first valve actuator means downwardly during upward movement of said second valve actuator means.

Claim 14

The apparatus of claim 10 wherein said chamber means is defined in part by said first valve actuator means, said second valve actuator means being sealingly slidable with respect to said first valve actuator means and said outer member.

Claim 15

The apparatus of claim 12 wherein said second valve actuator means includes upwardly facing surface means adapted to be engaged by downwardly facing surface means on said inner member to effect downward movement of said second valve actuator means in response to said telescoping relative movement.

Claim 16

The apparatus of claim 10 wherein said valve means includes a flapper valve element movable between a closed position transverse to said flow passage and an open position to the side thereof.

Claim 17

The apparatus of claim 10 further including equalizing valve means for equalizing the pressures of fluids in said flow passage above and below said valve means prior to the opening thereof by said first valve actuator means.

Claim 18

The apparatus of claim 10 further including piston means on said inner member movable in cylinder means on said outer member, the upper face of said piston means being subject to the pressure of fluids in said flow passage and the lower face of said piston means being subject to the pressure of fluids externally of said outer member, said piston and cylinder means being sized and arranged to balance out and cancel the net force on said members due to changes in the pressure of fluids in said flow passage.

Claim 19

The apparatus of claim 16 further including coengaged spline means on said members for preventing relative rotation thereof.