Boring tool locating signal frequency tracking apparatus

• US 8,754,648 B2
• Filed: 07/11/2011
• Issued: 06/17/2014
• Est. Priority Date: 06/01/1999
• Status: Expired due to Term

• Current Assignee: Merlin Technologies Incorporated
• Original Assignee: Merlin Technologies Incorporated
• Inventors: Brune, Guenter W., Mercer, John E.
• Primary Examiner(s): PATIDAR, JAY M
• Application Number:
  US13/179,691
• Publication Number:
  US 20110267064A1
• Time in Patent Office: 1,072 Days
• Field of Search: 324326-329, 175/45
• US Class Current: 324/326
• CPC Class Codes: E21B 47/02 Determining slope or direction
• 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 47/024 of devices in the borehole determining slope or direction of the borehole E21B47/022
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: E21B 47/12 Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
• CPC Class Codes: G01V 3/08 operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices with electromagnetic waves G01V3/12
• CPC Class Codes: G01V 3/081 the magnetic field is produced by the objects or geological structures characterised by the method of magnetic field measurement G01R33/00

Abstract

A transmitter transmits a locating signal from a boring tool by operating at a frequency that is selected as one of at least two operating frequencies for use in locating the boring tool. A receiver, forming part of the locator, cooperates with the locator to cause the locator to respond dynamically to a change of the selected one of the operating frequencies such that the locator tracks the selected operating frequency.

Claims

1. In a system in which a boring tool is moved through the ground in a region, said system including a locator at least for tracking the position of the boring tool as the boring tool moves through the ground, an apparatus comprising:

a transmitter for transmitting a locating signal from the boring tool by operating at a frequency that is selected as one of at least two operating frequencies available for use in locating the boring tool; and

a receiver, forming part of said locator, for cooperating with said transmitter in a way which causes the locator to respond dynamically to a change of the selected one of the operating frequencies, such that the locator tracks the selected operating frequency from said transmitter.

2. The apparatus of claim 1 wherein said transmitter includes locating a signal frequency controller to identify one of said operating frequencies to the receiver using a frequency code, which frequency code can individually identify each of said operating frequencies.

3. The apparatus of claim 2 wherein said locating signal frequency controller is configured to indicate an identified operating frequency to the receiver which is, at least initially, different from the selected operating frequency at which the transmitter is currently transmitting.

4. The apparatus of claim 2 wherein said locating signal frequency controller is configured to indicate an identified operating frequency to the receiver which is the same as the selected operating frequency at which the transmitter is currently transmitting.

5. The apparatus of claim 2 wherein said receiver is configured to receive the frequency code using a roll/pitch receiver.

6. The apparatus of claim 5 wherein said locating signal frequency controller and said receiver are configured to perform at least one of (i) maintaining the selected operating frequency if the identified operating frequency is equal to the selected operating frequency and (ii) changing the selected operating frequency to the identified operating frequency, as a new operating frequency, if the selected operating frequency is different from the identified operating frequency.