External Hollow Antenna

Patent metadata

Field	Value
Publication number	US-2016356146-A1
Application number	US-201514733340-A
Country	US
Kind code	A1
Filing date	Jun 8, 2015
Priority date	Jun 6, 2014
Publication date	Dec 8, 2016
Grant date	—

Abstract

A beacon assembly located at a downhole end of a drill string proximate a boring tool. The beacon assembly transmits data to an above-ground receiver. The beacon has a housing with a housing wall located between its sensors, such as gradiometers, accelerometers, and other orientation sensors, and an antenna assembly. The antenna assembly has a protective covering made of electromagnetically transparent material.

First claim

What is claimed is:

1 . A beacon assembly for attachment to a downhole end of a drill string, the beacon assembly comprising:
a housing wall; a sensor located within the housing wall; a coil electronically connected to the at least one sensor, the coil disposed outside of and about the housing wall.

2 . The beacon assembly of claim 1 further comprising a plurality of ferrite rods located between the coil and the housing wall.

3 . The beacon assembly of claim 1 further comprising:
an electromagnetically transparent protective casing located about the coil;
a conductive, non-magnetic shield disposed between the housing wall and the coil; and
a non-conductive, non-magnetic tube disposed between the shield and the coil.

4 . The beacon assembly of claim 3 wherein the electromagnetically transparent layer comprises ceramics.

5 . The beacon assembly of claim 1 wherein the housing wall has a varying diameter.

6 . The beacon assembly of claim 1 wherein the sensor is an orientation sensor.

7 . A beacon assembly for attachment to a downhole end of a drill string, the drill string comprising a substantially constant first diameter, the beacon assembly comprising:
a housing wall comprising a first portion and a second portion, wherein the first portion has substantially the first diameter, and the second portion has a second diameter, wherein the second diameter is less than the first diameter; an antenna located about the second portion of the housing wall; and a sensor located within the housing wall in electronic communication with the antenna.

8 . The beacon assembly of claim 7 further comprising a protective casing disposed about the antenna.

9 . The beacon assembly of claim 8 wherein the protective casing has substantially the first diameter.

10 . The beacon assembly of claim 7 wherein the sensor is located within the first portion of the housing wall.

11 . The beacon assembly of claim 7 wherein the antenna comprises a coil and a plurality of ferrite rods disposed between the coil and the housing wall.

12 . The beacon assembly of claim 7 wherein the housing wall further comprises a transition shoulder between the first portion and the second portion, wherein the antenna is connected to the sensor through the transition shoulder.

13 . A downhole tool coupled to a drill string comprising:
a sensor; an antenna electronically connected to the sensor; a wall disposed between the antenna and the sensor, the wall comprising a connection point for connection to the drill string; a conductive, non-magnetic shield disposed between the wall and the antenna; and a non-conductive, non-magnetic tube disposed between the shield and the antenna.

14 . The downhole tool of claim 13 wherein the antenna comprises a coil and a plurality of ferrite rods disposed between the coil and the wall.

15 . The downhole tool of claim 14 wherein the sensor is disposed within the coil and within the wall.

16 . The downhole tool of claim 13 wherein the sensor comprises an orientation sensor.

17 . The downhole tool of claim 13 wherein the wall comprises a first portion and a second portion, wherein the first portion has a greater diameter than the second portion and wherein the sensor is located within the first portion and the antenna coil is disposed about the second portion.

18 . The downhole tool of claim 13 further comprising a protective shell disposed about the antenna.

19 . The downhole tool of claim 13 further comprising a generator driven by the drill string for powering the antenna assembly.

20 . The downhole tool of claim 13 further comprising an insulating gap between the shield and the wall.

Assignees

• Charles Machine Works

Inventors

• Gard Michael F
• Bailey Brian K
• Sharp Richard F

Classifications

• E21B47/0232

  at least one of the energy sources or one of the detectors being located on or above the ground surface · CPC title

• H01Q1/526

  Electromagnetic shields · CPC title

• E21B7/046

  horizontal drilling (drilling with mechanical conveying means E21B7/003) · CPC title

• H01Q1/42

  Housings not intimately mechanically associated with radiating elements, e.g. radome · CPC title

• E21B47/024 Primary

  of devices in the borehole (determining slope or direction of the borehole E21B47/022) · CPC title