Ambient pressure responsive safety valve

Claim 2

A safety valve apparatus compriSing: valve means being supported by a well tubing and including coengageable means being movable between open and closed positions responsive to a pressure differential of a predetermined magnitude; and flow restriction means being disposed upstream of said valve means and being responsive to a decrease in ambient pressure in the well bore for developing said pressure differential.

Claim 3

A safety valve apparatus as recited in claim 1, wherein: said flow restriction means includes a movable element that restricts the flow of production fluid toward said valve element.

Claim 4

A safety valve apparatus as recited in claim 1, wherein: said valve means includes an inlet opening; and said developing means comprises a piston having a force due to said ambient pressure applied to one side thereof and a substantially constant preselected opposing force applied to the other side thereof.

Claim 5

A valve apparatus as recited in claim 3, wherein: said piston defines a plunger cooperating with said inlet opening to restrict the size of said opening responsive to said decrease in ambient pressure.

Claim 6

A safety valve apparatus adapted to be positioned within a well casing of a well having formation pressure comprising: valve housing means adapted for connection to the production tubing of said well, said housing means having inlet and outlet aperture means communicating said valve housing respectively with said casing and said production tubing; seat means disposed within said housing means; valve means disposed within a said housing means and being movable relative to said seat means for controlling the flow of fluid through said valve apparatus; means urging said valve means toward the open position thereof; valve actuator piston means being disposed in movable relation to said housing means and being movable relative to said valve housing responsive to predetermined pressure differential between ambient pressure and pressure within said valve housing means, said valve actuator means, upon being moved, inducing opening and closing movement to said valve means; and flow restricting means being supported within said well casing upstream of said valve means and being responsive to ambient pressure for controlling the flow of production fluid toward said valve means, said flow restricting means developing said predetermined pressure differential responsive to predetermined decrease in ambient pressure.

Claim 7

A safety valve apparatus adapted to be positioned within a well casing of a well having formation pressure comprising: valve housing means adapted for connection to the production tubing of said well, said housing means having inlet and outlet aperture means communicating said valve housing respectively with said casing and said production tubing; seat means disposed within said housing means; valve means disposed within a said housing means and being movable relative to said seat means for controlling the flow of fluid through said valve apparatus; means urging said valve means toward the open position thereof; valve actuator piston means being disposed in movable relation to said housing means and being movable relative to said valve housing responsive to predetermined pressure differential between ambient pressure and pressure within said valve housing means, said valve actuator means, upon being moved, inducing opening and closing movement to said valve means; and flow restricting means being supported within said well casing upstream of said valve means and being responsive to ambient pressure for controlling the flow of production fluid toward said valve means, said flow restricting means developing said predetermined pressure differential responsive to predetermined decrease in ambient pressure.

Claim 8

A safety valve apparatus as recited in claim 5, wherein said developing means comprises: piston means movable supported by said valve housing means and being movable between a position allowing unrestricted flow of fluid through said inlet aperture means and positions restricting the flow of fluid through said inlet aperture means; means urging said piston means toward said positions restricting the flow of fluid through said inlet aperture means; and ambient pressure acting upon said piston means and developing a force opposing said urging means and maintaining said piston means in the said position allowing unrestricted flow of fluid.

Claim 9

A safety valve apparatus as recited in claim 6: said housing defining a piston actuating chamber, said piston means being disposed in sealed relation relative to said piston actuating chamber; and a compressible medium disposed within said piston actuating chamber and urging said piston toward said second position thereof.

Claim 10

A safety valve apparatus as recited in claim 5: said housing defining pressure dome means; a piston movably carried by said pressure dome means and having a plunger portion thereof disposed for restricting relation with said inlet aperture means; means urging said piston toward a position restricting said inlet aperture means; and ambient pressure acting upon said piston and overcoming said urging means and maintaining said piston in a retracted position allowing unrestricted flow of fluid through said inlet aperture meAns, said urging means moving said plunger toward said restricting position upon decrease of said ambient pressure below a predetermined pressure level.

Claim 11

A safety valve apparatus as recited in claim 8: said means urging said piston toward said restricting position comprising a compression spring interposed between said housing means and said piston.

Claim 12

A safety valve apparatus as recited in claim 8: said means urging said piston toward said restricting position comprising a compressible medium disposed within said pressure dome and acting upon said piston, said compressible medium being normally of lower pressure than the normal operating range of said ambient pressure.

Claim 13

A safety valve apparatus as recited in claim 8: said valve housing defining a pressure dome; said piston extending in sealed relation into said pressure dome; and a compressible medium disposed within said pressure dome and acting upon said piston to urge said piston in a direction restricting said inlet aperture.

Claim 14

A safety valve apparatus as recited in claim 11: a compression spring disposed within said pressure dome and supplementing the urging force applied to said plunger by said compressible medium.

Claim 15

A safety valve apparatus comprising: housing means adapted for connection to the production tubing of a well having formation pressure for producing the well, said housing means defining flow passage means and having inlet aperture means communicating said flow passage means with ambient pressure and having an outlet aperture means communicating said flow passage means with said production tubing; seat means disposed within said housing; valve means movably disposed within said housing and being movable between open and closed positions relative to said seat means for controlling the flow of fluid through said flow passage means; means urging said valve means toward the open position thereof; piston means being carried by said valve means and being movable within said housing responsive to predetermined pressure differential between ambient pressure and pressure downstream of said valve means for moving said valve means to the closed position thereof against the bias of said urging means; and flow restricting means being supported within said casing upstream of said valve means and being responsive to ambient pressure for controlling the flow of production fluid toward said valve means, said flow restricting means developing said pressure differential responsive to a predetermined decrease in ambient pressure.

Claim 16

A safety valve apparatus comprising: housing means adapted for connection to the production tubing of a well having formation pressure for producing the well, said housing means defining flow passage means and having inlet aperture means communicating said flow passage means with ambient pressure and having an outlet aperture means communicating said flow passage means with said production tubing; seat means disposed within said housing; valve means movably disposed within said housing and being movable between open and closed positions relative to said seat means for controlling the flow of fluid through said flow passage means; means urging said valve means toward the open position thereof; piston means being carried by said valve means and being movable within said housing responsive to predetermined pressure differential between ambient pressure and pressure downstream of said valve means for moving said valve means to the closed position thereof against the bias of said urging means; and flow restricting means being supported within said casing upstream of said valve means and being responsive to ambient pressure for controlling the flow of production fluid toward said valve means, said flow restricting means developing said pressure differential responsive to a predetermined decrease in ambient pressure.

Claim 17

A safety valve apparatus as recited in claim 13: said flow restricting means being a movable element carried by said housing means and being movable between a position allowing full flow of production fluid through said inlet aperture and positions restricting the flow of production fluid through said inlet aperture; and means for moving said movable element toward said positions restricting the flow of production fluid.

Claim 18

A safety valve apparatus as recited in claim 14: said moving means comprising first and second urging means acting in combination; and said ambient pressure normally developing a force acting on said movable element overcoming both of said urging means and retaining said movable element in said position allowing full flow of production fluid.

Claim 19

A safety valve apparatus as recited in claim 13: said housing defining a piston carrier section; and a piston carried by said piston carrier section and being movable between a position allowing unrestricted flow of production fluid through said inlet aperture means and positions restricting flow of production fluid through said inlet aperture, movement of said piston being controlled by force differential responsive to predetermined decrease in ambient pressure.

Claim 20

A safety valve apparatus as recited in claim 16: said force differential acting upon said piston being defined by mechanically creaTed force urging said piston toward said positions restricting flow of production fluid and a force created by ambient pressure acting upon said plunger and urging said plunger toward said position allowing unrestricted flow of production fluid.

Claim 21

A safety valve apparatus as recited in claim 16: said force differential acting upon said plunger being defined by static pressure means acting upon said plunger and creating a force urging said plunger toward said positions restricting the flow of production fluid and a force created by ambient pressure acting upon said plunger and urging said plunger toward said position allowing unrestricted flow of production fluid.

Claim 22

A safety valve apparatus as recited in claim 17: said force differential acting upon said plunger being defined by a mechanically created force and a force defined by static pressure acting together upon said piston and urging said plunger toward said positions restricting the flow of production fluid and a force created by ambient pressure acting upon said plunger and urging said plunger toward said position allowing unrestricted flow of production fluid.