Claims
- 1. A reamer for use in horizontal directional drilling, the reamer comprising:a drive shaft; a front coupling disposed on a front end of the drive shaft, the front coupling configured to removably couple the reamer to a drill string; a carrier frame mounted about the drive shaft; a sun gear disposed on the drive shaft; at least one planet gear rotatably mounted to the carrier frame, the planet gear engaging the sun gear; a ring gear having a reaming surface, the ring gear being rotatably driven by the planet gear; an anti-rotation member hinged to the carrier frame; and wherein when the drive shaft is rotated, torque is transferred to the ring gear through the sun and the planet gear such that the ring gear is rotated at fewer revolutions per minute than the drive shaft.
- 2. The reamer according to claim 1 further comprising a spring disposed between the carrier frame and the anti-rotation member, the spring biasing the anti-rotation member toward a position away from the carrier frame.
- 3. A reamer for use in horizontal directional drilling, the reamer comprising:a drive shaft; a front coupling disposed on a front end of the drive shaft, the front coupling configured to removably couple the reamer to a drill string; a carrier frame mounted about the drive shaft; a mixing element disposed on the drive shaft; a sun gear disposed on the drive shaft; at least one planet gear rotatably mounted to the carrier frame, the planet gear engaging the sun gear; a ring gear having a reaming surface, the ring gear being rotatably driven by the planet gear; wherein when the drive shaft is rotated, torque is transferred to the mixing element and to the ring gear through the sun gear and planet gear such that the ring gear is rotated at fewer revolutions per minute than the drive shaft and the mixing element.
- 4. The reamer according to claim 3 further comprising a means for preventing rotation of the carrier frame.
- 5. The reamer according to claim 3 further comprising a rear coupling disposed on a rear end of the carrier frame, the rear coupling configured to removably couple the carrier frame of the reamer to a ream string.
- 6. The reamer according to claim 3 further comprising an anti-rotation member hinged to the carrier frame.
- 7. The reamer according to claim 6 further comprising a spring disposed between the carrier frame and the anti-rotation member, the spring biasing the anti-rotation member toward a position away from the carrier frame.
- 8. The reamer according to claim 3 wherein the carrier frame is configured to be removably coupled to an end of a conduit line.
- 9. A method for backreaming a pilot bore in horizontal directional drilling, the method comprising:running a drill string with a distal end through the pilot bore; coupling a backreamer including a mixing element and a reaming surface to the distal end of the drill string; pumping drilling fluid to the backreamer; rotating the reaming surface at a first speed while simultaneously rotating the mixing elements at a second speed faster than the first speed; drawing the rotating drill string and backreamer along the length of the pilot bore; and mixing the drilling fluid with dirt and cuttings into a slurry and displacing the slurry from the pilot bore.
- 10. A reamer assembly adapted to be driven by a drill string, the reamer assembly comprising:a reamer having a reaming surface; a torque transfer gear system for transferring torque from the drill string to the reamer, the torque transfer gear system being configured to rotate the reamer at a different speed than the drill string; and a mixing element coupled to the torque transfer gear system.
- 11. The reamer assembly of claim 10 wherein the reamer is rotated at a slower speed than the drill string.
- 12. The reamer assembly of claim 10 wherein the mixing element is rotated at a faster speed than the reamer.
- 13. A steerable reamer for use in horizontal directional drilling, the reamer comprising:a cutting body having an axis of rotation and configured to be removably coupled to a drill string; and an offset mount rotatably coupled to the cutting body such that the axis of rotation of the offset mount is collinear with the axis of rotation of the cutting body, the offset mount configured to be removably coupled to a ream line such that a longitudinal axis defined by the ream line is not collinear with the axis of rotation of the offset mount.
- 14. The reamer of claim 13 further comprising a back u-joint configured to couple the offset mount to the ream line.
- 15. The reamer of claim 14 further comprising a front u-joint configured to couple the drill string to the cutting body.
- 16. A steerable reamer for use in horizontal directional drilling, the reamer comprising:a cutting body having a front end and a back end and defining an axis of rotation; a front coupling configured to removably couple the front end of the cutting body to a drill string; a steering shaft having a front end and a back end, the front end of the steering shaft being rotatably coupled to the back end of the cutting body and centered on the cutting body's axis of rotation, the back end of the steering shaft being offset from the cutting body's axis of rotation; and a rear coupling configured to removably couple the back end of the steering shaft to a ream line.
- 17. The steerable reamer of claim 16 wherein the front coupling is coupled to the drill string by a front u-joint, and further wherein the back coupling is coupled to the ream line by a back u-joint.
- 18. A steerable reamer for use in horizontal directional drilling, the reamer comprising:a drive shaft characterized by an axis of rotation and configured to be removably coupled to a drill string; a carrier frame offset mount rotatably coupled to the drive shaft, the carrier frame offset mount configured to be coupled to a ream line such that a longitudinal axis of the ream line is not collinear with the axis of rotation of the drive shaft; a sun gear disposed on the drive shaft; at least one planet gear rotatably mounted to the carrier frame offset mount, the planet gear engaging the sun gear; a ring gear having a cutting surface rotatably coupled to the drive shaft, the ring gear being rotatably driven by the planet gear; wherein when the drive shaft is rotated, torque is transferred to the ring gear through the sun and the planet gears.
- 19. The reamer of claim 18 wherein the drive shaft is coupled to the drill string by a front u-joint, and further wherein the carrier frame offset mount is coupled to the ream line by a back u-joint.
- 20. A method for steering a reamer while reaming a pilot bore in horizontal directional drilling, the method comprising:providing a reamer having an offset mount that is rotatably coupled to a distal end of the reamer, the reamer being coupled to a drill string, the offset mount being coupled to a ream line; rotating and positioning the ream line to adjust the positioning of the offset mount and reamer, thereby inducing a change in the attitude of the reamer as the reamer is pulled through the pilot bore.
- 21. The method of claim 20 further comprising the step of providing a front u-joint to couple the reamer to the drill string and a distal u-joint to couple the offset mount of the reamer to the ream string.
- 22. The method of claim 20 wherein the drill string is coupled to a horizontal drilling machine and the ream line is coupled to an anchoring machine and further comprising the step of applying longitudinal force to the reamer by means of the anchoring machine to assist in redirecting the reamer.
- 23. A method for horizontal directional drilling, the method comprising:drilling a pilot bore from an entry point to an exit point with a drilling machine; connecting a reamer having an offset mount to a drill string which extends through the pilot bore at the exit point; positioning an anchor machine at the exit point of the pilot hole; connecting a ream line both to the reamer by means of the offset mount and to the anchor machine such that the anchor machine prevents the ream line from rotating; propelling the reamer back along the pilot bore by cooperation of the drilling machine and the anchor machine thereby reaming a hole, the anchor machine adding to the length of the ream line in the hole while the drilling machine is reducing the length of the drill string; and removing the reamer when the reamer exits at the entry point.
- 24. The method of claim 23 further comprising the steps of:connecting the ream line to the drilling machine; removing the anchor machine from the ream line; connecting a product line to the ream string at the exit point; and pulling the product line into the hole with the drilling machine.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. Provisional Application 60/217,563 and U.S. Provisional Application 60/218,008, both filed on Jul. 12, 2000.
US Referenced Citations (3)
Number |
Name |
Date |
Kind |
4381038 |
Sugden |
Apr 1983 |
A |
4789280 |
Dobat et al. |
Dec 1988 |
A |
5429198 |
Anderson et al. |
Jul 1995 |
A |
Provisional Applications (2)
|
Number |
Date |
Country |
|
60/217563 |
Jul 2000 |
US |
|
60/218008 |
Jul 2000 |
US |