Claims
- 1. A method for directionally drilling a well with a well casing as an elongated tubular drill string and a drilling assembly retrievable from the lower distal end of the drill string without withdrawing the drill string from a wellbore being formed by the drilling assembly, the method comprising: providing the casing as the drill string; providing a drilling assembly connected at the distal end of the drill string and being retrievable through the longitudinal bore of the drill string, the drilling assembly including a primary bit and a hole enlargement tool; providing a directional borehole drilling assembly connected to the drilling assembly and positioned to act in the well bore below the drill string and including biasing means for applying a force to the drilling assembly to drive it laterally relative to the wellbore, the directional borehole drilling assembly being at least in part retrievable from the wellbore through the longitudinal bore of the drill string; inserting the drill string, the directional borehole drilling assembly and the drilling assembly into the wellbore and driving the drilling assembly to operate to form a wellbore to a diameter greater than the diameter of the drill string; operating the biasing means to drive the drilling assembly laterally relative to the wellbore; removing at least the primary bit and the hole enlargement tool of the drilling assembly from the distal end of the drill string and moving the at least the primary bit and the hole enlargement tool of the drilling assembly with at least a part of the directional borehole drilling assembly connected thereto out of the wellbore through the drill string without removing the drill string from the wellbore; and leaving the drill string in the wellbore.
- 2. The method of claim 1 wherein after moving the at least the primary bit and the hole enlargement tool of the drilling assembly with at least a part of the directional borehole drilling assembly connected thereto out of the wellbore through the drill string, the method further comprises: replacing the at least the primary bit and the hole enlargement tool of the drilling assembly on the distal end of the drill string and operating the drilling assembly to continue formation of the wellbore.
- 3. The method of claim 2 further comprising replacing the at least a part of the directional borehole drilling assembly when replacing the at least the primary bit and the hole enlargement tool.
- 4. The method of claim 1 wherein the hole enlargement tool is an underreamer including radially expandable and retractable underreamer arms and the method comprises retracting the underreamer arms prior to moving the drilling assembly through the drill string.
- 5. An apparatus for drilling a wellbore in an earth formation comprising: a drill string having a longitudinal bore therethrough; a drilling assembly connected at the lower end of the drill string, the drilling assembly selected to be operable to form a borehole and including a primary bit and a hole enlargement tool, the hole enlargement tool acting to enlarge the wellbore diameter behind the primary bit and the primary bit and the hole enlargement tool being retrievable through the longitudinal bore of the drill string; and a directional borehole drilling assembly connected to the drilling assembly and including biasing means for applying a force to the drilling assembly selected to drive it laterally relative to the wellbore, the directional borehole drilling assembly selected at least in part to be retrievable through the longitudinal bore of the drill string.
- 6. The apparatus for drilling a wellbore of claim 5 wherein the hole enlargement tool is extendable and retractable relative to the primary bit.
- 7. The apparatus for drilling a wellbore of claim 5 wherein the directional borehole drilling assembly includes at least one of (a) a bent sub and (b) a bent housing.
- 8. The apparatus for drilling a wellbore of claim 5 wherein the directional borehole drilling assembly includes a modulated biasing means for forcing the drilling assembly away from one side of the borehole wall.
- 9. The apparatus for drilling a wellbore of claim 5 wherein the primary bit and the hole enlargement tool are driven by a downhole motor.
- 10. The apparatus for drilling a wellbore of claim 5 wherein the directional borehole drilling assembly is a rotary steerable tool and the rotary steerable tool is positioned between the primary bit and the hole enlargement tool.
- 11. The apparatus for drilling a wellbore of claim 5 wherein the directional borehole drilling assembly is a bent sub and the bent sub is positioned between the lower end of the drill string and the hole enlargement tool.
- 12. The apparatus for drilling a wellbore of claim 5 wherein the directional borehole drilling assembly is a bent motor housing and the bent motor housing is positioned between the lower end of the drill string and the hole enlargement tool.
- 13. The apparatus for drilling a wellbore of claim 5 wherein the primary bit and the hole enlargement tool are replaceable on the lower end of the drill string by running through the longitudinal bore of the drill string and once replaced are operable with the drill string to continue to form a borehole.
- 14. The apparatus for drilling a wellbore of claim 13 wherein the directional borehole drilling assembly is selected at least in part to be replaceable through the longitudinal bore of the drill string.
- 15. A method for directionally drilling a well with a well casing as an elongated tubular drill string and a drilling assembly retrievable from the lower distal end of the drill string without withdrawing the drill string from a wellbore being formed by the drilling assembly connected at the distal end of the drill string and being retrievable through the longitudinal bore of the drill string, the drill string including a primary bit and a hole enlargement tool, the method comprising: providing a directional borehole drilling assembly connected to the drilling assembly, the directional borehole drilling assembly including a rotary steerable tool for applying a force to the drilling assembly to drive it laterally relative to the wellbore, the directional borehole drilling assembly being positioned to act in the wellbore below the drill string and between the primary bit and the hole enlargement tool and being at least in part retrievable from the wellbore through the longitudinal bore of the drill string; inserting the drill string, the directional borehole drilling assembly and the drilling assembly into the wellbore and driving the drilling assembly to operate to form a wellbore to a diameter greater than the diameter of the drill string; operating the rotary steerable tool to drive the drilling assembly laterally relative to the wellbore; removing at least a portion of the drilling assembly from the distal end of the drill string and moving the at least a portion of the drilling assembly with at least a part of the directional borehole drilling assembly connected thereto out of the wellbore through the drill string without removing the drill string from the wellbore; and leaving the drill string in the wellbore.
- 16. The method of claim 15 wherein after moving the at least the primary bit and the hole enlargement tool of the drilling assembly with at least a part of the directional borehole drilling assembly connected thereto out of the wellbore through the drill string, the method further comprises replacing the at least the primary bit and the hole enlargement tool of the drilling assembly on the distal end of the drill string and operating the drilling assembly to continue formation of the wellbore.
- 17. The method of claim 16 further comprising replacing the at least a part of the directional borehole drilling assembly when replacing the at least the primary bit and the hole enlargement tool.
- 18. An apparatus for drilling a wellbore in an earth formation composing: a drill string having a longitudinal bore therethrough; a drilling assembly connected at the lower end of the drill string, the drilling assembly selected to be operable to form a borehole and at least in part to be retrievable through the longitudinal bore of the drill string and including a primary bit and a hole enlargement tool, the hole enlargement tool acting to enlarge the wellbore diameter behind the primary bit; and a directional borehole drilling assembly connected between the primary bit and the hole enlargement tool and including a rotary steerable tool for applying a force to the drilling assembly to drive it laterally relative to the wellbore, the directional borehole drilling assembly selected at least in part to be retrievable through the longitudinal bore of the drill string.
- 19. The apparatus for drilling a wellbore of claim 18 wherein the hole enlargement tool is extendable and retractable relative to the primary bit.
- 20. The apparatus for drilling a wellbore of claim 18 wherein the primary bit and the hole enlargement tool are replaceable on the lower end of the drill string by running through the longitudinal bore of the drill string and once replaced are operable with the drill string to continue to form a borehole.
- 21. The apparatus for drilling a wellbore of claim 20 wherein the directional borehole drilling assembly is selected at least in part to be replaceable through the longitudinal bore of the drill string.
- 22. A method for directionally drilling a well with a well casing as an elongated tubular drill string and a drilling assembly retrievable from the lower distal end of the drill string without withdrawing the drill string from a wellbore being formed by the drilling assembly, the method comprising: providing the casing as the drill string; providing a drilling assembly connected at the distal end of the drill string and being retrievable through the longitudinal bore of the drill string, the drill string including a primary bit and a hole enlargement tool; providing a directional borehole drilling assembly connected to the drilling assembly, the directional borehole drilling assembly including a rotary steerable tool for applying a force to the drilling assembly to drive it laterally relative to the wellbore, the directional borehole drilling assembly being positioned to act in the wellbore below the drill string and between the primary bit and the hole enlargement tool and being at least in part retrievable from the wellbore through the longitudinal bore of the drill string; inserting the drill string, the directional borehole drilling assembly and the drilling assembly into the wellbore and driving the drilling assembly to operate to form a wellbore to a diameter greater than the diameter of the drill string; operating the rotary steerable tool to drive the drilling assembly laterally relative to the wellbore; removing at least the primary bit and the hole enlargement tool of the drilling assembly from the distal end of the drill string and moving the at least the primary bit and the hole enlargement tool of the drilling assembly with at least a part of the directional borehole drilling assembly connected thereto out of the wellbore through the drill string without removing the drill string from the wellbore; and leaving the drill string in the wellbore.
- 23. The method of claim 22 wherein the hole enlargement tool is an underreamer including radially expandable and retractable underreamer arms and the method comprises retracting the underreamer arms prior to moving the drilling assembly through the drill string.
- 24. The method of claim 22 wherein after moving the at least the primary bit and the hole enlargement tool of the drilling assembly with at least a part of the directional borehole drilling assembly connected thereto out of the wellbore through the drill string, the method further comprises replacing the at least the primary bit and the hole enlargement tool of the drilling assembly on the distal end of the drill string and operating the drilling assembly to continue formation of the wellbore.
- 25. The method of claim 24 further comprising replacing the at least a part of the directional borehole drilling assembly when replacing the at least the primary bit and the hole enlargement tool.
- 26. An apparatus for drilling a wellbore in an earth formation comprising: a drill string having a longitudinal bore therethrough; a drilling assembly connected at the lower end of the drill string, the drilling assembly selected to be operable to form a borehole and including a primary bit and a hole enlargement tool, the hole enlargement tool acting to enlarge the wellbore diameter behind the primary bit and the primary bit and the hole enlargement tool being retrievable through the longitudinal bore of the drill string; and a directional borehole drilling assembly connected between the primary bit and the hole enlargement tool and including a rotary steerable tool for applying a force to the drilling assembly to drive it laterally relative to the wellbore, the directional borehole drilling assembly selected at least in part to be retrievable through the longitudinal bore of the drill string.
- 27. The apparatus for drilling a wellbore of claim 26 wherein the hole enlargement tool is extendable and retractable relative to the primary bit.
- 28. The apparatus for drilling a wellbore of claim 26 wherein the primary bit and the hole enlargement tool are replaceable on the lower end of the drill string by running through the longitudinal bore of the drill string and once replaced are operable with the drill string to continue to form a borehole.
- 29. The apparatus for drilling a wellbore of claim 28 wherein the directional borehole drilling assembly is selected at least in part to be replaceable through the longitudinal bore of the drill string.
- 30. An apparatus for drilling a wellbore in an earth formation comprising: a drill string having a longitudinal bore therethrough; and an assembly including a primary bit at its first end, an underreamer adjacent its opposite end, the underreamer including radially expandable and retractable underreamer arms operable to enlarge the wellbore diameter behind the primary bit, and a directional borehole drilling assembly positioned between the primary bit and the underreamer, the assembly being releasably connectable at the lower end of the drill string to be operable to form a directionally selected borehole and being retrievable through the longitudinal bore of the drill string.
- 31. The apparatus for drilling a wellbore of claim 30 wherein the assembly is replaceable on the lower end of the drill string by running through the longitudinal bore of the drill string and once replaced is operable with the drill string to continue to form the borehole.
- 32. The apparatus for drilling a wellbore of claim 30 wherein the opposite end of the assembly is connectable at the lower end of the drill string and the assembly is formed such that the underreamer and primary bit rotate with drill string and the directional borehole drilling assembly includes a rotary steerable tool.
- 33. A method for directionally drilling a well with a well casing as an elongated tubular drill string and a drilling assembly retrievable from the lower distal end of the drill string without withdrawing the drill string from a wellbore being formed by the drilling assembly, the method comprising: providing the casing as the drill string; providing an assembly including a primary bit at its first end, an underreamer adjacent its opposite end, the underreamer including radially expandable and retractable underreamer arms operable to enlarge the wellbore diameter behind the primary bit, and a directional borehole drilling assembly positioned between the primary bit and the underreamer, the assembly being operable to form a directionally selected borehole and being moveable through the longitudinal bore of the drill string; connecting the assembly at its opposite end to the distal end of the drill string such that the underreamer, directional borehole drilling assembly and primary bit extend out below the drill string; inserting the drill string and the assembly into the wellbore and operating the drilling assembly to form a wellbore to a diameter greater than the diameter of the drill string; operating the directional borehole drilling assembly to select the direction of the wellbore; removing the assembly from the distal end of the drill string and moving the assembly out of the wellbore through the drill string without removing the drill string from the wellbore; and leaving the drill string in the wellbore.
- 34. The method of claim 33 wherein the opposite end of the assembly is connected at the lower end of the drill string such that the underreamer and the primary bit rotate with the drill string and the directional borehole drilling assembly includes a rotary steerable tool.
- 35. The method of claim 33 wherein after moving the assembly out of the wellbore through the drill string, the method further comprises replacing the assembly on the distal end of the drill string and operating the assembly to continue formation of the wellbore.
Parent Case Info
This application claims subject matter disclosed in prior filed provisional application serial No. 60/122,755, filed Feb. 23, 1999.
US Referenced Citations (25)
Foreign Referenced Citations (2)
Number |
Date |
Country |
530045 |
Mar 1993 |
EP |
571 045 |
Nov 1993 |
EP |
Non-Patent Literature Citations (1)
Entry |
Warren, Tommy Trends Toward Rotary Steerable Directiona Systems. World Oil May 1997. |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/122755 |
Feb 1999 |
US |