System, arrangements and associated methods for tracking and/or guiding an underground boring tool

• US 6,095,260 A
• Filed: 10/21/1999
• Issued: 08/01/2000
• Est. Priority Date: 04/16/1997
• Status: Expired due to Term

• Current Assignee: Merlin Technologies Incorporated
• Original Assignee: Digital Control Incorporated
• Inventors: Mercer, John E., Zeller, Rudolf, Brune, Guenter W., Moore, Lloyd A., Ng, Shiu S., Hambling, Peter H.
• Primary Examiner(s): SCHOEPPEL, ROGER J
• Application Number:
  US09/422,814
• Time in Patent Office: 285 Days
• Field of Search: 175/24, 175/26, 175/40, 175/45, 175/62, 342/448, 342/449, 342/450, 342/459
• US Class Current: 175/45
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/0232 at least one of the energy sources or one of the detectors being located on or above the ground surface
• CPC Class Codes: E21B 47/04 Measuring depth or liquid level
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 21/29 Combinations of different interacting antenna units for giving a desired directional characteristic H01Q25/00 takes precedence
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Abstract

Systems and associated methods for tracking and/or guiding an underground boring tool are disclosed. Each system or arrangement uses one or more detectors to measure the intensity of an electromagnetic field which is transmitted from an underground boring tool. The measured intensities may then be used to determine the location of the boring tool. In a dead reckoning embodiment of the invention, one detector may be employed while, in a position determination embodiment, two or more detectors may be employed. In any embodiment, physically measurable parameters may be used in addition to measured magnetic intensities. A highly advantageous mapping tool instrument and a cubic antenna are disclosed. The former for use in the position determination embodiment and the latter for use in any magnetic field detector employed herein. A highly advantageous apparatus and associated method for determining the movement of the boring tool underground by monitoring the motion of a drill string, which is attached to the boring tool and extends to a drill rig, are also disclosed wherein measurements are performed relating to movement of the drill string at the drill rig.

Claims

1. A method of tracking the position and certain orientation parameters of a boring tool in the ground as the boring tool moves along a path which lies within a particular coordinate system, said method comprising the steps of:

(a) providing the boring tool with means for transmitting an electromagnetic field;

(b) providing only one detector, the detector having an electromagnetic field receiving antenna assembly including at least one antenna,

positioning the detector provided at a fixed position and at a particular orientation within said coordinate system, and

determining the position and particular orientation within said coordinate system of the antenna associated with the detector provided;

(c) at least periodically transmitting said electromagnetic field from said boring tool when the boring tool is at certain positions on said path;

(d) when the boring tool is at one point on said path, establishing its position and said certain orientation parameters of the boring tool within the coordinate system;

(e) moving said boring tool along said path which includes said one point and at least a subsequent second point;

(f) when the boring tool moves a distance along said path from said one point to said second point, measuring at least one component of the intensity of said electromagnetic field using said detector; and

(g) determining, at least to an approximation, the position and orientation of the boring tool at said second point within the coordinate system using as a first input the electromagnetic field intensity measurement or measurements taken by said detector when the boring tool is at said second point, the position of said boring tool at said one point and said certain orientation parameters of the boring tool at said one point being used along with said electromagnetic field intensity measurement or measurements to determine, at least to an approximation, the position of the boring tool and said orientation parameters at said second point.

2. A method of tracking the position and certain orientation parameters of a boring tool in the ground as the boring tool moves along a path which lies within a particular coordinate system, said coordinate system being a Cartesian coordinate system defined by a horizontal x-axis, a horizontal y-axis and a vertical z-axis, said method comprising the steps of:

(a) providing the boring tool with means for transmitting an electromagnetic field;

(b) providing only one detector, said detector having an electromagnetic field receiving antenna assembly including first, second and third antennas which are orthogonal with respect to one another,

positioning the detector provided at a fixed position and at a particular orientation within said coordinate system, and

determining the position and particular orientation within said coordinate system of the antenna associated with the detector provided;

(c) at least periodically transmitting said electromagnetic field from said boring tool when the boring tool is at certain positions on said path;

(d) when the boring tool is at one point on said path, establishing its position and said certain orientation parameters of the boring tool within the coordinate system;

(e) moving said boring tool along said path which includes said one point and at least a subsequent second point;

(f) when the boring tool moves a distance along said path from said one point to said second point, measuring at least one component of the intensity of said electromagnetic field using said detector; and

(g) determining, at least to an approximation, the position and orientation of the boring tool at said second point within the coordinate system using as a first input the electromagnetic field intensity measurement or measurements taken by said detector when the boring tool is at said second point.

3. A method of tracking the position of a boring tool in the ground as the latter moves along a path which lies within a Cartesian coordinate system defined by a horizontal x-axis, a horizontal y-axis normal to the x-axis and a vertical z-axis, said method comprising the steps of:

(a) providing the boring tool with means for transmitting an electromagnetic field and locating the boring tool at a starting point;

(b) providing a detector with an electromagnetic field receiving antenna assembly including first, second and third receiving antennas mounted orthogonal to one another, positioning said detector at a fixed location within said coordinate system but not necessarily along the intended path of movement of said boring tool, and determining the position and orientation of the first, second and third antennas within said coordinate system;

(c) at least periodically transmitting said electromagnetic field from said boring tool at various points along the path of movement of said boring tool;

(d) when the boring tool is at the starting point of said path, initially establishing its coordinates and its pitch and yaw angles within the coordinate system;

(e) moving said boring tool a distance Δ

L from said starting point to a second point;

(f) when the boring tool moves the distance Δ

L along said path from the starting point thereof to a second point, measuring first, second and third components of the intensity of said electromagnetic field using the three antennas of said detector; and

(g) from said initially established coordinates, initial pitch and yaw angles and the electromagnetic field intensity measurements taken when the boring tool is at said second point, determining at least to an approximation the distance Δ

L and coordinates of the boring tool and also the pitch and yaw angles of the boring tool at said second point within the coordinate system.

4. A method according to claim 3 wherein said initially established coordinates, initial pitch and yaw angles and the electromagnetic field intensity measurements taken when the boring tool is at said second point are the only inputs required in determining at least to an approximation the distance Δ

L, the coordinates of the boring tool and its pitch and yaw angles at said second point within the coordinate system.

5. In an overall method of tracking the position of a boring tool in the ground as the latter moves along a path which lies within a Cartesian coordinate system, a method of tracking the boring tool'"'"'s x-axis and y-axis position within said coordinate system and its yaw angle, comprising the steps of:

(a) providing the boring tool with means for transmitting an electromagnetic field and locating the boring tool at a starting point;

(b) providing a detector with an electromagnetic field receiving antenna assembly including first and second receiving antennas mounted orthogonal to one another, positioning said detector at a fixed location within said Cartesian coordinate system but not necessarily along the intended path of movement of said boring tool, and determining the position and orientation of the first and second antennas within said coordinate system;

(c) at least periodically transmitting said electromagnetic field from said boring tool at various points along the path of movement of said boring tool;

(d) when the boring tool is at the starting point of said path, initially establishing its x-axis and y-axis positions and its yaw angle within the coordinate system;

(e) when the boring tool moves a particular distance along said path from the starting point thereof to a second point, measuring first and second components of the intensity of said electromagnetic field using the two antennas of said detector; and

(f) from said initially established x-axis and y-axis positions and the initial yaw angle and the electromagnetic field intensity measurements taken when the boring tool is at said second point, determining at least to an approximation the x-axis and y-axis positions of the boring tool and its yaw angle at said second point within the coordinate system.

6. A method according to claim 5 wherein said initially established x-axis and y-axis positions and initial yaw angle and the electromagnetic field intensity measurements taken when the boring tool is at said second point are the only inputs required in determining at least to an approximation the x-axis and y-axis positions of the boring tool and its yaw angle at said second point within the coordinate system.

7. A method of tracking the position of a boring tool in the ground as the latter moves along a path which lies a coordinate system, said method comprising the steps of:

(a) providing the boring tool with a pitch sensor and means for transmitting an electromagnetic field and locating the boring tool at a starting point;

(b) providing a detector with an electromagnetic field receiving antenna assembly including first, second and third receiving antennas mounted orthogonal to one another, positioning said detector at a fixed location within said coordinate system but not necessarily along the intended path of movement of said boring tool, and determining the position and orientation of the first, second and third antennas within said coordinate system;

(c) at least periodically transmitting said electromagnetic field from said boring tool at various points along the path of movement of said boring tool;

(d) when the boring tool is at the starting point of said path, initially establishing its position and its pitch and yaw angles within the coordinate system;

(e) when the boring tool moves a particular distance along said path from the starting point thereof to a second point, measuring first, second and third components of the intensity of said electromagnetic field using the three antennas of said detector and measuring its pitch using said pitch sensor; and

(f) from said initial position, initial pitch angle, initial yaw angle and the electromagnetic field intensity and pitch measurements taken when the boring tool is at said second point, determining at least to an approximation the coordinates of the boring tool and its yaw angle at said second point within the coordinate system.

8. A method according to claim 7, wherein said initially established position and initial pitch and yaw angles and the electromagnetic field intensity and pitch measurements taken when the boring tool is at said second point are the only inputs required in determining at least to an approximation the coordinates of the boring tool and its yaw angle at said second point within the coordinate system.

9. In a system in which a boring tool is moved through the ground in a region, an arrangement for tracking the position and/or guiding the boring tool as it moves through the ground, said arrangement comprising:

(a) means located within said boring tool for transmitting an electromagnetic field;

(b) one detector means for receiving said electromagnetic field, the detector means having an electromagnetic field receiving antenna assembly including at least one antenna for measuring at least one component of the intensity of said electromagnetic field, the detector being positioned at a fixed position with its antenna at a particular orientation within said region;

(c) means for determining certain initial conditions prior to drilling which include the position of said detector in said region, the particular orientation of the antenna associated with the detector provided and an initial position and orientation of the boring tool; and

(d) processing means for using at least one measured component of the intensity of said electromagnetic field, which is obtained using said detector after the boring tool moves a distance along said path, in determining, at least to an approximation, the position of the boring tool after moving said distance.