Inground transmitter with roll orientation pattern based frequency change

• US 9,915,747 B2
• Filed: 11/23/2016
• Issued: 03/13/2018
• 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:
  US15/359,762
• Publication Number:
  US 20170075018A1
• Time in Patent Office: 475 Days
• Field of Search: 324326-329
• 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 for use in an inground tool transmits a locating signal for tracking an underground position of the inground tool. The locating signal is characterized by a transmission frequency which changes responsive to detecting a roll orientation pattern in which the transmitter is held stationary for a predetermined period of time.

Claims

1. A transmitter for use in an inground tool as part of a system in which the inground tool is moved underground in a region, said transmitter comprising:

a transmitter section for transmitting a locating signal from the inground tool for use in tracking an underground position of the inground tool in said region, the locating signal characterized by a transmission frequency;

a sensor for detecting a roll orientation of the transmitter; and

a processor coupled to the sensor to monitor the detected roll orientation to identify a roll orientation pattern including at least one roll orientation at which the transmitter is held stationary for a predetermined period of time and to change the transmission frequency responsive to detecting the roll orientation pattern.

2. The transmitter of claim 1 wherein said sensor is a three axis accelerometer.

3. The transmitter of claim 1 wherein the locating signal is a dipole signal.

4. The transmitter of claim 1 wherein the roll orientation pattern includes a sequence of roll position orientations.

5. The transmitter of claim 4 wherein the transmitter is held stationary at each one of the roll position orientations.