System and method for automatically drilling and backreaming a horizontal bore underground

• US 20040028476A1
• Filed: 07/12/2003
• Published: 02/12/2004
• Est. Priority Date: 01/12/2000
• Status: Abandoned Application

• Current Assignee: Charles Machine Works Incorporated The
• Original Assignee: Charles Machine Works Incorporated The
• Inventors: Stevens, Norman E. Jr., Stangl, Gerald A., Gard, Michael F., Payne, David R.
• Application Number:
  US10/617,975
• Publication Number:
  US 20040028476A1
• Time in Patent Office: Days
• US Class Current: 405/184
• CPC Class Codes: E21B 19/20 Combined feeding from rack and connecting, e.g. automatically
• CPC Class Codes: E21B 44/00 Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003
• CPC Class Codes: E21B 7/28 Enlarging drilled holes, e.g. by counterboring

Abstract

A system and method for automatically drilling and backreaming a horizontal borehole underground. The system includes a horizontal drilling machine and a machine control system for operating the drilling machine. The machine control system has sensors and control circuits for monitoring and automatically controlling the functions of the drilling machine. The machine control system manages the power consumption of the drilling machine, the fluid dispensed during drilling and backreaming, the lengthening and shortening of the drill string, the tracking and recording of progress along a selected bore path, and the guiding of the downhole tool along the selected bore path. In a drilling operation the method involves identifying a selected bore path and automatically guiding the downhole tool along the selected bore path. In a backreaming operation the method involves connecting a backreamer and a utility line to the drill string and automatically pulling the utility line back through the borehole.

Claims

1. A method for installing a utility line in a borehole comprising:

drilling a pilot borehole; and

automatically backreaming the pilot borehole while installing a utility line.

2. The method of claim 18 further comprising attaching the utility line to a backreamer.

3. The method of claim 19 further comprising recording the actual location of the utility line installed underground as the utility line is automatically pulled through the borehole.

4. A method for backreaming a horizontal borehole, the method comprising:

automatically pulling a drill string through the horizontal borehole;

automatically reducing a length of the drill string when the drill string must be shortened;

automatically reducing a rate of pullback if the rotation pressure on the drill string is greater than a predetermined limit; and

automatically reducing a rate of pullback if the product tension is greater than a predetermined limit.