Mudline emergency shutoff for offshore wells

Claim 2

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means movable from the platform through the conductor pipe extension and incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff valve means movable from the platform through the conductor pipe extension and supported on said casing hanger means, extension conduit means adapted to extend through the conductor pipe extension from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member movable through the conductor pipe extension and shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means movable through the conductor pipe extension and adapted to hold said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure.

Claim 3

In apparatus for producing an offshore well as defined in claim 1, said production fluid conduit means and said extension conduit means having a plurality of conduits for production fluid from a plurality of well zones, said shutoff valve means including a plurality of said passages establishing communication between the respective conduit means and one of said valve members for opening and closing each of said passages.

Claim 4

In apparatus for producing an offshore well as defined in claim 1, said control fluid pressure operated means comprising an actuator piston engaged with said vaLve member, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including means responsive to movement of said actuator piston to move said valve member from said second position to said first position to store energy for returning said valve member to said second position from said first position. 4. In apparatus for producing an offshore well as defined in claim 1, said control fluid pressure operated means comprising an actuator piston engaged with said valve member, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including means responsive to movement of said actuator piston to move said valve member from said second position to said first position to store energy for returning said valve member to said second position from said first position, and supplemental means for actuating said valve member to said second position.

Claim 5

In apparatus for producing an offshore well as defined in claim 1, said control fluid pressure operated means comprising an actuator piston engaged with said valve member, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including means responsive to movement of said actuator piston to move said valve member from said second position to said first position to store energy for returning said valve member to said second position from said first position, and supplemental means for actuating said valve member to said second position, said supplemental means including means for supplying fluid pressure to said power piston chamber to augment the said energy storing means.

Claim 6

In apparatus for producing an offshore well as defined in claim 1, connector means interposed between said shutoff valve means and said casing hanger means, said connector means having latch means interfitting with said casing hanger means when said connector means and said shutoff valve means are lowered into said casing hanger means through said conductor pipe extension.

Claim 7

In apparatus for producing an offshore well as defined in claim 1, said shutoff valve means comprising a valve chamber intersected by said passage, and a valve gate slidable in said chamber between said first and second positions.

Claim 8

In apparatus for producing an offshore well as defined in claim 1, said shutoff valve means comprising a valve chamber intersected by said passage, a valve gate slidable in said chamber between said first and second positions, said control fluid pressure operated means comprising an actuator piston having a rod connected with said valve gate, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including means responsive to movement of said actuator piston to move said valve gate from said second position to said first position to store energy for returning said valve gate to said second position from said first position.

Claim 9

In apparatus for producing an offshore well as defined in claim 1, said shutoff valve means comprising a valve chamber intersected by said passage, a valve gate slidable in said chamber between said first and second positions, said control fluid pressure operated means comprising an actuator piston engaged with said valve gate, a piston chamber in which said actuator piston is reciprocable, said piston having a rod connected to said valve gate in said valve chamber, said means for moving said valve member to said second position including means responsive to movement of said actuator piston to move said valve gate from said second position to said first position to store energy for returning said valve gate to said second position from said first position, and supplemental means for actuating said valve member to said second position.

Claim 10

In apparatus for producing an offshore well, wherein a platform is at the surface oF the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, production conduit means including a casing string for communicating with one well zone and at least one tubing string in said casing string for communicating with another well zone, said extension conduit means including an extension conduit for each of said well zones, said shutoff valve means having a passage communicating between the respective extension conduits, said casing and said tubing, and one of said valve members for opening and closing each of said passages.

Claim 11

In apparatus for producing an offshore well, wherein a platform is at the surface oF the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, production conduit means including a casing string for communicating with one well zone and at least one tubing string in said casing string for communicating with another well zone, said extension conduit means including an extension conduit for each of said well zones, said shutoff valve means having a passage communicating between the respective extension conduits, said casing and said tubing, and one of said valve members for opening and closing each of said passages.

Claim 12

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said control fluid pressure operated means comprising an actuator piston engaged with said valve member, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including a power piston, a piston chamber in which said power piston is reciprocable, energy storing means normally urging said power piston in one direction, passage means leading between the respective piston chambers at one side of each of said pistons, hydraulic fluid filling said piston chamber and said passage means between said pistons, whereby when said actuator piston is moved by control fluid pressure to move said valve member from said second position to said first position, said power piston is moved in the other direction to store energy in said energy storing means for moving said power piston in said one direction and said valve member to said first position when control fluid pressure is reduced.

Claim 13

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said control fluid pressure operated means comprising an actuator piston engaged with said valve member, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including a power piston, a piston chamber in which said power piston is reciprocable, energy storing means normally urging said power piston in one direction, passage means leading between the respective piston chambers at one side of each of said pistons, hydraulic fluid filling said piston chamber and said passage means between said pistons, whereby when said actuator piston is moved by control fluid pressure to move said valve member from said second position to said first position, said power piston is moved in the other direction to store energy in said energy storing means for moving said power piston in said one direction and said valve member to said first position when control fluid pressure is reduced.

Claim 14

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means aNd said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said control fluid pressure operated means comprising an actuator piston engaged with said valve member, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including means responsive to movement of said actuator piston to move said valve member from said second position to said first position to store energy to return said valve member to said second position from said first position, and supplemental means for actuating said valve member to said second position, said supplemental means including an override piston, a piston chamber in which said override piston is reciprocable, said override piston engaging said valve member to move the latter to its second position, and means for supplying pressure fluid to said override position chamber.

Claim 15

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means aNd said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said control fluid pressure operated means comprising an actuator piston engaged with said valve member, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including means responsive to movement of said actuator piston to move said valve member from said second position to said first position to store energy to return said valve member to said second position from said first position, and supplemental means for actuating said valve member to said second position, said supplemental means including an override piston, a piston chamber in which said override piston is reciprocable, said override piston engaging said valve member to move the latter to its second position, and means for supplying pressure fluid to said override position chamber.

Claim 16

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means including means for hanging a plurality of casing strings in the well and defining an annular space between adjacent casing strings, and including passage means communicating with said annular space and extensible to the platform to enable monitoring of the pressure in said annular space.

Claim 17

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means including means for hanging a plurality of casing strings in the well and defining an annular space between adjacent casing strings, and including passage means communicating with said annular space and extensible to the platform to enable monitoring of the pressure in said annular space.

Claim 18

In apparatus for producing an offshore well as defined in claim 13, and monitoring valve means in said passage means for enabling pressurization of said annular space when said monitoring valve means are closed and said monitoring of the pressure in said annular space when said monitoring valve means are open.

Claim 19

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, connector means interposed between said shutoff valve means and said casing hanger means, said connector means having latch means interfitting with said casing hanger means when said connector means and said shutoff valve means are lowered into said casing hanger means through said conductor pipe extension, said casing hanger means supporting in the well a casing string for communicating with one well zone and at least one tubing string in said casing string for communication with another well zone, and extension conduit means including an extension conduit for each of said well zones, said shutoff valve means having a passage communicating with the respective extension conduits, and one of said valve members for opening and closing each of said passages, said connector means forming a seal between said casing string and said tubing string and having passages communicating between said passages in said shutoff valve means, said casing and said tubing.

Claim 20

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, connector means interposed between said shutoff valve means and said casing hanger means, said connector means having latch means interfitting with said casing hanger means when said connector means and said shutoff valve means are lowered into said casing hanger means through said conductor pipe extension, said casing hanger means supporting in the well a casing string for communicating with one well zone and at least one tubing string in said casing string for communication with another well zone, and extension conduit means including an extension conduit for each of said well zones, said shutoff valve means having a passage communicating with the respective extension conduits, and one of said valve members for opening and closing each of said passages, said connector means forming a seal between said casing string and said tubing string and having passages communicating between said passages in said shutoff valve means, said casing and said tubing.

Claim 21

In apparatus for producing an offshore well as defined in claim 15, said casing hanger supporting an outer string of casing defining with the first-mentioned casing string an annular space therebetween, said communicator means forming a seal in said annular space, said connector means and said shutoff valve means also having pressure monitoring passage means opening into said annular space through said connector means.

Claim 22

In apparatus for producing an offshore well as defined in claim 15, said casing hanger supporting an outer string of casing defining with the first-mentioned casing string an annular space therebetween, said connector means forming a seal in said annular space, said connector means and said shutoff valve means also having pressure monitoring passage means opening into said annular space through said connector means, and normally closed valve means for closing said pressure monitoring passage means until said connector means is lowered into said casing hanger means, said normally closed valve means being opened when said connector means is lowered into said casing hanger means.

Claim 23

In apparatus for producing an offshore well as defined in claim 15, said casing hanger means supporting an outer string of casing defining with the first-mentioned casing string an annular space therebetween, said connector means forming a seal in said annular space.

Claim 24

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means supporting in the well a casing string for communicating with one well zone, and at least one tubing string in said casing string for communicating with another well zone, said extension conduit means including an extension conduit for each of said well zones, said shutoff valve means having a passage communiating with the respective extension conduits, and one of said valve members for opening and closing each of said passages, and including connector means interposed between said shutoff valve means and said casing hanger means and forming a seal between said casing and said tubing string, said connector means having passages communicating between said passages in said shutoff valve, said casing and said tubing.

Claim 25

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means supporting in the well a casing string for communicating with one well zone, and at least one tubing string in said casing string for communicating with another well zone, said extension conduit means including an extension conduit for each of said well zones, said shutoff valve means having a passage communiating with the respective extension conduits, and one of said valve members for opening and closing each of said passages, and including connector means interposed between said shutoff valve means and said casing hanger means and forming a seal between said casing and said tubing string, said connector means having passages communicating between said passages in said shutoff valve, said casing and said tubing.

Claim 26

In apparatus for producing an offshore well as defined in claim 19, said casing hanger supporting an outer string of casing defining with the first-mentined casing string an annular space there between, said connector means forming a seal in said annular space, said connector means and said shutoff valve means also having pressure monitoring passage means opening into said annular space through said connector means.

Claim 27

In apparatus for producing an offshore well as defined in claim 19, said casing hanger supporting an outer string of casing defining with the first-mentioned casing string an annular space therebetween, said connector means forming a seal in said annular space, said connector means and said shutoff valve means also having pressure monitoring passage means opening into said annular space through said connector means, and normally closed valve means for closing said pressure monitoring passage means until said connector means is lowered into said casing hanger means, said normally closed valve means being opened when said connector means is lowered into said casing hanger means.

Claim 28

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means comprising a housing connected to the lower end of said conductor pipe extension, a first casing hanger for supporting a first inner casing string in the well, a second casing hanger supported by said first casing hanger for supporting another inner string of casing in the well, said housing, said strings of casing and said casing hangers defining annular spaces opening upwardly therebetween, and including connector means interposed between said shutoff valve means and said casing hangers, means connecting said connector means to said casing hanger means, and means on said connector means and said casing hanger means forming a seal between the connector means, said housing and said casing hanger closing off said annular spaces.

Claim 29

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means comprising a housing connected to the lower end of said conductor pipe extension, a first casing hanger for supporting a first inner casing string in the well, a second casing hanger supported by said first casing hanger for supporting another inner string of casing in the well, said housing, said strings of casing and said casing hangers defining annular spaces opening upwardly therebetween, and including connector means interposed between said shutoff valve means and said casing hangers, means connecting said connector means to said casing hanger means, and means on said connector means and said casing hanger means forming a seal between the connector means, said housing and said casing hanger closing off said annular spaces.

Claim 30

In apparatus for producing an offshore well as defined in claim 22, said connector means also having pressure monitoring passage means communicating with said annular spaces and extensible to the platform to enable the monitoring of the pressure in said annular spaces.

Claim 31

In apparatus for providing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, and shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means comprising a housing at the lower end of said conductor pipe extension, a plurality of casing hanger bodies supported in said housing for supporting successive inner casing strings within said housing, and including connector means interposed between said shutoff valve means and said casing hanger bodies and forming a seal between said housing and said casing hanger bodies.

Claim 32

In apparatus for providing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, and shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said casing hanger means comprising a housing at the lower end of said conductor pipe extension, a plurality of casing hanger bodies supported in said housing for supporting successive inner casing strings within said housing, and including connector means interposed between said shutoff valve means and said casing hanger bodies and forming a seal between said housing and said casing hanger bodies.

Claim 33

In apparatus for producing an offshore well as defined in claim 24, said connector means including an intermediate connector member, one of said casing hanger bodies and said inermediate connector member having means for securing said intermediate connector member to said one of said casing hanger bodies, said intermediate connector member having passages opening into the spaces between said housing and said casing hanger bodies, normally closed valve means in the latter passages, an upper connector member engageable with said intermediate connector member when said upper connector member and said shutoff valve means are lowered through said conductor pipe extension, said upper connector member, the innermost casing hanger body and said intermediate connector member having means forming chambers therebetween upon engagement of said upper connector member with said intermediate connector member, said chambers communicating with said passages in said intermediate connector members upon opening of said normally closed valve means, means on said upper connector member and said normally closed valve means for opening the latter upon engagement of said upper connector member with said intermediate member, and passages in said upper connector member communicating with said chambers and extensible to the platform to enable monitoring of the pressure in said chambers at the platform.

Claim 34

In apparatus for producing an offshore well as defined in claim 24, said connector means including an intermediate connector member, one of said casing hanger bodies and said intermediate connector member having means for securing said intermediate connector member to said one of said casing hanger bodies, said intermediate connector member having passages opening into the spaces between said housing and said casing hanger bodies, normally closed valve means in the latter passages, an upper connector member engageable with said intermediate connector member when said upper connector member and said shutoff valve means are lowered through said conductor pipe extension, said upper connector member, the innermost casing hanger body and said intermediate connector member having means forming chambers therebetween upon engagement of said upper connector member with said intermediate connector member, said chambers communicating with said passsages in said intermediate connector member upon opening of said normally closed valve means, means on said upper connector member and said normally closed valve means for opening the latter upon engagement of said upper connector member with said intermediate member, passages in said upper connector member communicating with said chambers and extensible to the platform to enable monitoring of the pressure in said chambers at the platform, and said upper connector member and said housing having latch means coengageable to hold said upper connector member in engagement with said intermediate connector member upon engagement of said upper connector member with said intermediate connector member.

Claim 35

In apparatus for producing an offshore well as defined in claim 24, said connector means including a connector body engageable with said casing hanger bodies upon lowering of said connector body and said shutoff valve means into said housing, said connector body and said housing having latch means coengageable to hold said connector body in engagement with said casing hanger bodies upon engagement of said connector body with said casing hanger bodies.

Claim 36

In apparatus foR producing an offshore well as defined in claim 24, said connector means including a connector body engageable with said casing hanger bodies upon lowering of said connector body and said shutoff valve means into said housing, said connector body and said housing having latch means coengageable to hold said connector body in engagement with said casing hanger bodies upon engagement of said connector body with said casing hanger bodies, said connector body having pressure monitoring passages therein communicating with the spaces between said housing and said casing hanger bodies to enable monitoring at the platform of the pressure in said spaces.

Claim 37

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said extension conduit means comprising a number of extension joints, each of said joints having complemental pin and box ends having means for interconnecting said joints together, each joint including an outer casing and an inner tubing adapted to receive well fluid when said valve passage is open, said tubing having a stabbing sub at one end and a complemental receptacle at the other end for interconnecting the tubing of the interconnected joints.

Claim 38

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said extension conduit means comprising a number of extension joints, each of said joints having complemental pin and box ends having means for interconnecting said joints together, each joint including an outer casing and an inner tubing adapted to receive well fluid when said valve passage is open, said tubing having a stabbing sub at one end and a complemental receptacle at the other end for interconnecting the tubing of the interconnected joints.

Claim 39

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said shutoff valve means comprising a valve chamber intersected by said passage, a valve gate slidable in said chamber between said first and second positions, said control fluid pressure operated means comprising an actuator piston connected with said valve gate, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including a power piston, a piston chamber in which said power piston is reciprocable, energy storing means normally urging said power piston in one direction, passage means leading between the respective platform chambers at one side of each of said pistons, hydraulic fluid filling said piston chambers and said passage means between said pistons, whereby when said actuator piston is moved by control fluid pressure to move said valve gate from said second position to said first position, said powEr piston is moved in the other direction to store energy in said energy storing means for moving said power piston in said one direction and said valve gate to said first position when control fluid pressure is reduced.

Claim 40

In apparatus for producing an offshore well, wherein a platform is at the surface of the water, wellhead equipment is located at the mudline, and a conductor pipe extension extends between the platform and the wellhead equipment: casing hanger means incorporated in said wellhead equipment, production fluid conduit means extending into the well from said casing hanger means, shutoff means within said conductor pipe extension and supported on said casing hanger means, extension conduit means extending from said shutoff valve means to said platform, said shutoff valve means having a passage communicating between said production fluid conduit means and said extension conduit means, a valve member shiftable between a first position at which said passage is open and a second position at which said passage is closed, control fluid pressure operated means for holding said valve member in said first position, and means for moving said valve member to said second position upon reduction in control fluid pressure, said shutoff valve means comprising a valve chamber intersected by said passage, a valve gate slidable in said chamber between said first and second positions, said control fluid pressure operated means comprising an actuator piston connected with said valve gate, a piston chamber in which said actuator piston is reciprocable, said means for moving said valve member to said second position including a power piston, a piston chamber in which said power piston is reciprocable, energy storing means normally urging said power piston in one direction, passage means leading between the respective platform chambers at one side of each of said pistons, hydraulic fluid filling said piston chambers and said passage means between said pistons, whereby when said actuator piston is moved by control fluid pressure to move said valve gate from said second position to said first position, said powEr piston is moved in the other direction to store energy in said energy storing means for moving said power piston in said one direction and said valve gate to said first position when control fluid pressure is reduced.