Claims
- 1. A method of isolating a junction between a first wellbore and a second wellbore extending outwardly from the first wellbore, the method comprising the steps of:
providing an elongated assembly including an outer generally tubular structure and an inner generally tubular structure, a first flow passage being formed through the inner structure and a second flow passage being formed between the inner and outer structures; sealing a first longitudinal portion of the assembly within a first interior sealing area of the first wellbore uphole of the junction, and sealing a second longitudinal portion of the assembly within a second interior sealing area of a selected one of (1) a portion of the first wellbore downhole from the junction and (2) a portion of the second wellbore, in a manner such that the assembly sealingly straddles the junction with the first and second flow passages being isolated from the non-selected wellbore portion; and flowing fluid, via one of the first and second flow passages, through the assembly between the sealing areas while returning circulation of the fluid, via the other one of the first and second flow passages through the assembly between the sealing areas.
- 2. The method of claim 1 wherein the one of the first and second flow passages is the first flow passage.
- 3. The method of claim 1 wherein the selected wellbore portion is the portion of the first wellbore downhole from the junction.
- 4. The method of claim 1 wherein the selected wellbore portion is the portion of the second wellbore.
- 5. The method of claim 1 wherein the sealing steps are performed using packers providing sliding seals with the first and second interior sealing areas.
- 6. The method of claim 1 wherein the sealing steps isolate the junction from a first annulus portion formed between the assembly and the first wellbore above the junction, and wherein the flowing step further comprises flowing the fluid between the second flow passage and the first annulus portion.
- 7. The method of claim 6 wherein the sealing steps isolate the junction from a second annulus portion formed between the assembly and the selected wellbore portion below the junction, and wherein the flowing step further comprises flowing the fluid between the second flow passage and the second annulus portion.
- 8. The method of claim 1 wherein the inner structure is sealingly engaged with the outer structure at opposite ends of the inner structure.
- 9. The method of claim 1 wherein the assembly is positioned and operatively sealed within its associated wellbore portions in a single trip into the first wellbore.
- 10. For use in a subterranean well having a first wellbore extending downwardly from the surface, and a second wellbore extending outwardly from the first wellbore, a method of treating a formation intersected by one of the wellbores, the method comprising the steps of:
providing an elongated assembly including an outer generally tubular structure and an inner generally tubular structure, a first flow passage being formed through the inner structure and a second flow passage being formed between the inner and outer structures, the assembly further including first and second spaced apart external sealing devices; lowering the assembly through the first wellbore in a manner such that the first sealing device is positioned in a portion of the first wellbore uphole of the junction, and the second sealing device is positioned within a selected one of (1) a portion of the first wellbore downhole from the junction, and (2) a portion of the second wellbore; sealingly engaging the first and second sealing devices with their associated wellbore portions to thereby cause the assembly to sealingly straddle the junction; and flowing a well treatment fluid through one of the first and second passages into the selected wellbore portion.
- 11. The method of claim 10 wherein the flowing step is performed by flowing the well treatment through the first passage into the selected wellbore portion.
- 12. The method of claim 11 wherein in the flowing step the first flow passage is isolated from the non-selected wellbore portion.
- 13. The method of claim 10 wherein the first and second sealing devices are packers forming sliding seals with their associated wellbore portions.
- 14. The method of claim 10 wherein the selected wellbore portion is the portion of the first wellbore downhole from the junction.
- 15. The method of claim 10 wherein the selected wellbore portion is the portion of the second wellbore.
- 16. The method of claim 10 wherein in the sealingly engaging step, the first and second sealing devices divide an annulus formed between the assembly, a portion of the first wellbore above the junction, and the selected wellbore portion into first, second and third portions, the second portion being isolated from the non-selected wellbore portion.
- 17. For use in a subterranean well having a first wellbore extending downwardly from the surface and a second wellbore extending outwardly from the first wellbore at a junction therewith, a wellbore isolation system comprising:
an assembly including an elongated section having first and second sealing devices at opposite ends of the section, the first sealing device sealingly engaging a portion of the first wellbore uphole of the junction, and the second sealing device sealingly engaging a selected one of (1) a portion of the first wellbore downhole from the junction and (2) a portion of the second wellbore, the assembly thereby sealingly straddling the junction, the assembly further including an outer generally tubular structure and an inner generally tubular structure, a first flow passage being formed through the inner structure and a second flow passage being formed between the inner and outer structures; and fluid flowing through the section via the first flow passage, the first flow passage being isolated from the non-selected wellbore portion.
- 18. The wellbore isolation system of claim 17 wherein the second flow passage is isolated from the first flow passage and from the non-selected wellbore portion.
- 19. The wellbore isolation system of claim 18 wherein the second flow passage is in communication with the first wellbore above the section and with the selected wellbore portion below the section.
- 20. The wellbore isolation system of claim 17 wherein the second flow passage extends through a first port in the sidewall of the second structure above the first sealing device, and the second flow passage extends through a second port in the second structure sidewall below the second sealing device.
- 21. The wellbore isolation system of claim 17 wherein the assembly is operatively installed in a single trip into the first wellbore.
- 22. The wellbore isolation system of claim 17 wherein the first and second sealing devices slidingly and sealingly engage their associated wellbore portions.
- 23. The wellbore isolation system of claim 22 wherein the first and second sealing devices are cup packers.
- 24. The wellbore isolation system of claim 17 wherein the selected wellbore portion is the portion of the first wellbore downhole from the junction.
- 25. The wellbore isolation system of claim 17 wherein the selected wellbore portion is the portion of the second wellbore.
- 26. The wellbore isolation system of claim 17 wherein:
the well is a subsea well, and the wellbore isolation system further comprises means, associated with the assembly, for automatically compensating for rig heave without breaking the seals between the first and second sealing devices and their associated wellbore portions.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of copending U.S. application Ser. No. 09/637,494 filed on Aug. 11, 2000, the disclosure of such copending application being hereby incorporated in its entirety herein by reference.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09637494 |
Aug 2000 |
US |
Child |
10115783 |
Apr 2002 |
US |