초록 ▼

A wellhead system diverter spool contains an internal sleeve that can be axially shifted internal to the spool with a handling tool. The sleeve permits access to outlets in the spool when required. When higher pressures are required, the internal sleeve is shifted downward to close off access to th

A wellhead system diverter spool contains an internal sleeve that can be axially shifted internal to the spool with a handling tool. The sleeve permits access to outlets in the spool when required. When higher pressures are required, the internal sleeve is shifted downward to close off access to the outlets without change out of equipment or changing the BOP stack riser system. The low pressure lines connected to the outlets can remain installed but are isolated from the higher pressure BOP stack pressures.

대표청구항 ▼

What is claimed is: 1. A wellhead system, comprising: a lower diverter adapted to be disposed in a wellhead system between a blowout preventer (BOP) and a wellhead housing assembly, the lower diverter having an axial bore and a pressure outlet extending from the axial bore for discharging drilling

What is claimed is: 1. A wellhead system, comprising: a lower diverter adapted to be disposed in a wellhead system between a blowout preventer (BOP) and a wellhead housing assembly, the lower diverter having an axial bore and a pressure outlet extending from the axial bore for discharging drilling mud therefrom, the lower diverter comprising: a sleeve located in and axially movable relative to the axial bore, the sleeve having an upward axial position and a downward axial position, wherein access from the axial bore to the pressure outlet is unimpeded when the sleeve is disposed in the upward axial position; and a sleeve retainer screw to secure the sleeve in the upward axial position. 2. A wellhead system according to claim 1, wherein the lower diverter comprises a drilling adapter having an upper axial shoulder for landing the sleeve in the upward axial position, a body secured to the drilling adapter and having a lower axial shoulder for landing the sleeve in the downward axial position, and the pressure outlet extends through the body. 3. A welthead system according to claim 2, wherein the sleeve actually straddles the drilling adapter and the body in the upward axial position, and the sleeve is axially located entirely within the body in the downward axial position. 4. A wellhead system according to claim 1, further comprising an overshot mandrel located between an upper diverter and the BOP. 5. A wellhead system according to claim 1, further comprising a handing tool adapted to extend through an upper diverter and the BOP for moving the sleeve between the upward axial and downward axial positions. 6. A wellhead system according to claim 1, wherein the sleeve retainer screw comprises at least one radially movable sleeve retainer screw for engaging and securing a lower end of the sleeve in the upward axial position of the sleeve, and engaging and securing an upper end of the sleeve in the downward axial position of the sleeve. 7. A wellhead system according to claim 1, wherein the lower diverter comprises locator screws for engaging a locator sleeve for locating an axial position of a handling tool relative to the sleeve, the handling tool being adapted to extend through the BOP to move the sleeve between the upward axial position and the downward axial position. 8. A wellhead system according to claim 5, wherein the handling tool comprises a locator sleeve, the locator sleeve being axially movable along a portion of the handling tool, the locator sleeve having a lower position for locating the handling tool at an upper end of the sleeve to push the sleeve down to the downward axial position, and an upper position for locating the handling tool at a lower end of the sleeve to pull the sleeve upward to an open position. 9. A wellhead system according to claim 1, wherein access from the axial bore to the pressure outlet is unimpeded when the sleeve is in the upward axial position and access from the axial bore to the pressure outlet is impeded when the sleeve is in the downward axial position. 10. A diverter for a wellhead system, comprising: a drilling adapter having an axial bore, and an upper axial shoulder in the axial bore; a body securable to a lower end of the drilling adapter and having an axial bore concentric with the axial bore of the drilling adapter, a lower axial shoulder formed in the axial bore of the body, and low pressure outlets extending radially through the body; a sleeve located in and axially movable relative to the axial bores of the drilling adapter and the body, the sleeve landing on the upper axial shoulder in an open position such that access to the low pressure outlets is unimpeded, and the sleeve landing on the lower axial shoulder in a closed position for impeding access to the low pressure outlets; and a sleeve locking system for mechanically locking the sleeve in the closed position. 11. A diverter according to claim 10, wherein the sleeve axially straddles the drilling adapter and the body in the open position, and the sleeve is axially located entirely within the body in the closed position. 12. A diverter according to claim 10, further comprising a handling tool for moving the sleeve between the open and closed positions. 13. A diverter according to claim 10, wherein the sleeve locking system comprises a plurality of radially movable sleeve retainer screws for engaging and securing an upper end of the sleeve in the closed position. 14. A diverter according to claim 10, wherein the drilling adapter comprises locator screws extending radially therethrough for engaging a locator sleeve for locating an axial position of a handling tool relative to the sleeve, the handling tool being adapted to extend through the BOP to move the sleeve between the open position and the closed position. 15. A diverter according to claim 12, wherein the handling tool comprises a locator sleeve, the locator sleeve is being axially movable along a portion of the handling tool, the locator sleeve having a lower position for locating the handling tool at an upper end of the sleeve to push the sleeve down to the closed position, and an upper position for locating the handling tool at a lower end of the sleeve to pull the sleeve upward to the open position. 16. A method of controlling discharge of drilling mud in a wellhead system, the method comprising: assembling a wellhead system with a lower diverter having an axial bore and an outlet mounted axially in the wellhead system below an upper diverter and a blowout preventer (BOP) and above a wellhead housing assembly; positioning a sleeve in the lower diverter in an open position to enable drilling mud to be discharged from the axial bore through the outlet; positioning the sleeve in a closed position to block drilling mud from being discharged from the axial bore through the outlet; and mechanically securing the sleeve in the closed position to prevent the sleeve from being repositioned from the closed position to the open position. 17. A method according to claim 16, wherein positioning the sleeve in the lower diverter in the open position comprises landing the sleeve on an upper axial shoulder in the lower diverter, and positioning the sleeve in the closed position comprises landing the sleeve on a lower axial shoulder in the lower diverter. 18. A method according to claim 16, further comprising extending a handling tool through the upper diverter and the BOP to move the sleeve between the open and closed positions. 19. A method according to claim 18, further comprising engaging and disengaging the sleeve with hydraulically-actuated, radially movable pins on the handling tool to move the sleeve between the open and closed positions. 20. A method according to claim 18, further comprising engaging and disengaging a lower end of the sleeve with radially movable sleeve retainer screws on the lower diverter in the open position, and engaging and securing an upper end of the sleeve with the retainer screws in the closed position. 21. A method according to claim 18, further comprising providing a locator sleeve on the handling tool, and locator screws on the lower diverter for engaging the locator sleeve, and locating an axial position of the handling tool relative to the sleeve with the locator sleeve and locator screws. 22. A method according to claim 21, further comprising axially moving the locator sleeve relative to the handling tool, such that the locator sleeve has a lower position for locating the handling tool at an upper end of the sleeve to push the sleeve down to the closed position, and an upper position for locating the handling tool at a lower end of the sleeve to pull the sleeve upward to the open position. 23. A wellhead system according to claim 1, comprising: a sleeve retainer screw to secure the sleeve in the downward axial position. 24. A method of controlling discharge of drilling mud in a wellhead system, the method comprising: assembling a wellhead system with a lower diverter having an axial bore and an outlet mounted axially in the wellhead system below a blowout preventer (BOP) and above a wellhead housing assembly; positioning a sleeve in the lower diverter in an open position to enable drilling mud to be discharged from the axial bore through the outlet; and mechanically securing the sleeve in the open position to prevent the sleeve from being repositioned from the open position to a closed position that blocks drilling mud from being discharged from the axial bore through the outlet. 25. A method according to claim 24, further comprising: releasing the sleeve to enable the sleeve to be repositioned from the open position; and repositioning the sleeve from the open position to the closed position to block drilling mud from being discharged from the axial bore through the outlet. 26. A method according to claim 25, further comprising: mechanically securing the sleeve in the closed position to prevent the sleeve from being repositioned from the closed position to the open position.