초록 ▼

A retrievable tree cap for use on a subsea tree having a concentric bore. The tree cap may be installed and retrieved using a remotely operated vehicle. Hydraulic pressure may be used to lock the tree cap onto the subsea tree and to set the tree cap seals. The tree cap is locked onto the subsea tree

A retrievable tree cap for use on a subsea tree having a concentric bore. The tree cap may be installed and retrieved using a remotely operated vehicle. Hydraulic pressure may be used to lock the tree cap onto the subsea tree and to set the tree cap seals. The tree cap is locked onto the subsea tree before setting the seals within the concentric bore. The tree cap includes a locking means that may engage a profile within the subsea tree regardless of the radial orientation of the tree cap. The tree cap may be used to hydraulically isolate an annulus bore from the production bore of the subsea tree. The tree cap may provide for the injection of a corrosion inhibitor within a cavity of the tree cap and may also provide for the removal of water trapped between the tree cap and the subsea tree.

대표청구항 ▼

What is claimed is: 1. A tree cap for a subsea tree having an annulus bore and a production bore, the tree cap comprising: a cylindrical body having an upper end and a lower end, the cylindrical body having an upper fluid port in communication with a lower fluid port; a cap connected to the upper e

What is claimed is: 1. A tree cap for a subsea tree having an annulus bore and a production bore, the tree cap comprising: a cylindrical body having an upper end and a lower end, the cylindrical body having an upper fluid port in communication with a lower fluid port; a cap connected to the upper end of the cylindrical body, the cap including an opening through the cap; a rod positioned through the opening in the cap, the rod having an upper end above the cap and a lower end positioned within the cylindrical body; a cam connected to the rod within the cylindrical body; a spring positioned about the rod between the cap and the cam, the spring being biased to move the cam from an upper position to a lower position; a lower locking dog movable between an inner position and an outer position, wherein in the inner position the lower locking dog retains the cam in its upper position; a seal carrier slideably connected to the cylindrical body, the seal carrier being selectively movable between a first position and a second position and having an upper seal and a lower seal, wherein in the first position the seal carrier retains the lower locking dog in its inner position and in the second position the seal carrier releases the lower locking dog and the upper seal and lower seal of the seal carrier isolate the annulus bore from the production bore; a sleeve having an upper seal and a lower seal and being slideably connected to the upper end of the cylindrical body, the sleeve being movable between a first position, a second position, and a third position, wherein in the first position and the second position the upper seal and the lower seal of the sleeve hydraulically isolate the upper fluid port of the cylindrical body; a housing connected around the sleeve, the housing creating a cavity between the sleeve and the housing; an upper locking dog selectively movable between an inner position and an outer position, the upper locking dog being biased to its inner position, wherein in its outer position the upper locking dog is adapted engage a profile in the subsea tree; a plate connected to the cylindrical body; syntactic foam connected to the plate; a hot stab injector selectively connected to the plate and being in fluid communication with the cavity between the housing and the sleeve, wherein fluid pressure applied through the hot stab injector moves the sleeve from the first position to the second position moving the upper locking dog to its outer position; wherein fluid pressure applied through the hot stab injector moves the sleeve from the second position to the third position moving the upper seal past the upper fluid port of the cylindrical body, the upper fluid port being in fluid communication with the cavity between the sleeve and the housing; and wherein fluid pressure applied through the hot stab injector passes through the upper fluid port to the lower fluid port and moves the seal carrier to the second position releasing the lower locking dog to move to its outer position. 2. The tree cap of claim 1, wherein a corrosion inhibitor is applied through the hot stab injector. 3. The tree cap of claim 1 further comprising a centralizer connected to the seal carrier. 4. The tree cap of claim 1, wherein the upper seal and lower seal of the seal carrier are metal-to-metal seals. 5. The tree cap of claim 4 further comprising an upper elastomeric seal adjacent the upper metal-to-metal seal and a lower elastomeric seal adjacent the lower metal-to-metal seal. 6. The tree cap of claim 1 further comprising a handle connected to the upper end of the cylindrical body, the handle being movable from an upright vertical position to a lower horizontal position. 7. The tree cap of claim 1 further comprising a longitudinal bore within the rod, wherein the longitudinal bore may be used to pressure test below the seal carrier. 8. The tree cap of claim 1 further comprising a longitudinal bore within the rod in communication with a radial bore through the seal carrier, wherein the longitudinal bore may be used to pressure test the seals of the seal carrier. 9. The tree cap of claim 1, wherein the tree cap may be installed in the subsea tree with a remotely operated vehicle. 10. The tree cap of claim 9, wherein the remotely operated vehicle may remove the hot stab injector after the seal carrier is moved to the second position. 11. The tree cap of claim 1, wherein the tree cap may be installed in the subsea tree at any radial orientation. 12. The tree cap of claim 1, wherein the distance of the upper end of the rod above the cap indicates the position of the seal carrier. 13. A tree cap for installation in a subsea tree having an annulus bore and a production bore, the tree cap comprising: a cap; a cylindrical body being connected to the cap; means for selectively locking the cylindrical body to a profile in the subsea tree, wherein the locking means is hydraulically actuated; a seal carrier slideably connected to the cylindrical body, the seal carrier being movable between a non-actuated position and an actuated position, wherein the seal carrier is adapted to hydraulically isolate the annulus bore and the production bore of the subsea tree in the actuated position; means for hydraulically moving the seal carrier to the actuated position after locking the cylindrical body to the profile; and hydraulic injection means, wherein the means for hydraulically moving the seal carrier is configured to come into fluid communication with the hydraulic injection means only after the locking means is hydraulically actuated. 14. The tree cap of claim 13 further comprising means for selectively locking the seal carrier in the actuated position. 15. The tree cap of claim 13 wherein the tree cap may be installed into the subsea tree at any radial orientation. 16. The tree cap of claim 13 further comprising means for injecting a corrosion inhibitor into a cavity between the tree cap and the subsea tree. 17. The tree cap of claim 16 further comprising means for removing water trapped between the tree cap and the subsea tree. 18. The tree cap of claim 13, wherein the hydraulic injection means is a hot stab injector, and wherein fluid pressure from the hot stab injector first actuates the locking means and then moves the seal carrier to the actuated position. 19. A method for installing a tree cap on a subsea tree, the method comprising: moving the tree cap to the subsea tree with a remotely operated vehicle; inserting the tree cap into a bore in the subsea tree; applying fluid pressure to the tree cap with a hot stab injector selectively connected to the tree cap; locking the tree cap into the subsea tree, wherein locking dogs are engaged by the fluid pressure from the hot stab injector; and setting seals of the tree cap to isolate an annulus bore and production bore of the subsea tree, wherein the seals are set after locking the tree cap into the subsea tree. 20. The method of claim 19 further comprising injecting a corrosion inhibitor through the hot stab injector into a cavity between the tree cap and the subsea tree. 21. The method of claim 20 further comprising removing water trapped between the tree cap and the subsea tree. 22. The method of claim of claim 19 further comprising moving a handle of the tree cap with the remotely operated vehicle from a vertical position to a horizontal position. 23. The method of claim 19 further comprising removing the hot stab injector with the remotely operated vehicle. 24. The method of claim 19, wherein the tree cap may be inserted at any radial orientation into the bore of the subsea tree. 25. The method of claim 19, wherein fluid pressure from the hot stab injector sets the seals of the tree cap. 26. A tree cap fur use with a subsea tree having a concentric bore, the tree cap comprising: a cylindrical body having a top end and a bottom end; a cap connected to the top end of the cylindrical body; a seal carrier slideably connected to the bottom end of the cylindrical body movable between an upper position and a lower position, the seal carrier including a plurality of seals adapted to seal the concentric bore of the subsea tree in the lower position of the seal carrier a first locking means connected to the cylindrical body, the first locking means being adapted to selectively engage a profile in the concentric bore of the subsea tree, wherein the first locking means is adapted to engage the profile of the concentric bore for any radial orientation of the cylindrical body; a second locking means connected to the cylindrical body, the second locking means being adapted to selectively retain the seal carrier in the lower position; and a hot stab injector, wherein fluid pressure from the hot stab first actuates the first locking means and then moves the seal carrier to the lower position, wherein the second locking means selectively retains the seal carrier in the lower position. 27. The tree cap of claim 26 further comprising a plate connected to the cylindrical body, an upper portion of syntactic foam connected to an upper portion of the plate, and a lower portion of syntactic foam connected to a lower portion of the plate.