Well ranging apparatus, methods, and systems

Patent metadata

Field	Value
Publication number	US-2016103240-A1
Application number	US-201514865659-A
Country	US
Kind code	A1
Filing date	Sep 25, 2015
Priority date	Oct 10, 2014
Publication date	Apr 14, 2016
Grant date	—

Abstract

Apparatus, systems, and methods may operate to couple a power supply to a ground point associated with a well, and to a lower portion of a conductive casing disposed within the well, where the lower portion of the conductive casing is separated by an insulating gap from an upper portion of the conductive casing, the upper portion of the conductive casing being at a higher elevation of the first well than the lower portion of the conductive casing. Further activity may include injecting an excitation signal into the lower portion of the conductive casing to induce a magnetic field in a geological formation surrounding the first well. Additional apparatus, systems, and methods are disclosed.

First claim

What is claimed is:

1 . A method, comprising:
coupling a power supply to a ground point associated with a first well, and to a lower portion of a conductive casing disposed within the first well, the lower portion of the conductive casing separated by an insulating gap from an upper portion of the conductive casing, wherein the upper portion of the conductive casing is at a higher elevation of the first well than the lower portion of the conductive casing; and injecting an excitation signal into the lower portion of the conductive casing to induce a magnetic field in a geological formation surrounding the first well.

2 . The method of claim 1 , further comprising:
receiving a ranging signal corresponding to the magnetic field at a sensor disposed in a second well.

3 . The method of claim 2 , further comprising:
processing the ranging signal to determine a distance or direction to the first well, from the second well.

4 . The method of claim 2 , wherein the first well is a target well and the second well is a drilling well.

5 . The method of claim 2 , wherein the first well is a drilling well and the second well is a target well.

6 . The method of claim 1 , wherein the coupling comprises:
coupling the power supply to a ground point that is less than 100 m from an opening of the first well in a surface of the Earth.

7 . A method, comprising:
casing a well with a conductive casing separated by insulating gaps into at least two portions; and attaching an insulated conductor to a lower one of the portions that is separated from an upper one of the portions by at least one of the insulating gaps, to form an excitation signal injection point that is not directly electrically coupled to the upper one of the portions, wherein the upper one of the portions is at a higher elevation of the well than the lower one of the portions.

8 . The method of claim 7 , further comprising:
prior to casing the well with the conductive casing, casing the well with an outer casing that has an inner diameter that is larger than the outer diameter of the conductive casing.

9 . The method of claim 7 , further comprising:
moving the excitation signal injection point from a first one of the lower one of the portions to a second one of the lower one of the portions.

10 . An apparatus, comprising:
a well having a conductive casing separated by at least one insulating gap into at least two portions; and an insulated conductor directly electrically coupled to a lower one of the portions that is separated from an upper one of the portions by the at least one insulating gap, to form an excitation signal injection point that is not directly electrically coupled to the upper one of the portions, wherein the upper one of the portions is at a higher elevation of the well than the lower one of the portions.

11 . The apparatus of claim 10 , wherein the at least one insulating gap is less than one meter in length.

12 . The apparatus of claim 10 , further comprising:
a ground point electrically coupled to a surface of the Earth, wherein the ground point is less than 100 m from an opening of the well on the surface of the Earth.

13 . The apparatus of claim 12 , further comprising:
a power supply electrically coupled to the ground point and to the lower one of the portions.

14 . The apparatus of claim 10 , further comprising:
an actuator to move the excitation signal injection point from a first one of the lower one of the portions, to a second one of the lower one of the portions.

15 . An apparatus, comprising:
an upper well casing portion; and a lower well casing portion having an excitation signal injection terminal, wherein the lower well casing portion is joined to the upper well casing portion by insulating gap material disposed between the upper well casing portion and the lower well casing portion.

16 . The apparatus of claim 15 , wherein the insulating gap material comprises a polymer, rubber, or glass.

17 . The apparatus of claim 15 , wherein at least one of the upper well casing portion or the lower well casing portion comprises a conductive metal at least partially surrounded by casing insulation material, to reduce current leakage into a geological formation when current is injected into the lower well casing portion via the terminal.

18 . The apparatus of claim 17 , wherein the casing insulation material comprises a polymer, rubber, or glass.

19 . A system, comprising:
a first well having a conductive casing separated by at least one insulating gap into at least two portions, and an insulated conductor directly electrically coupled to a lower one of the portions that is separated from an upper one of the portions by the at least one insulating gap, to form an excitation signal injection point that is not directly electrically coupled to the upper one of the portions, wherein the upper one of the portions is at a higher elevation of the well than the lower one of the portions; a second well including a signal receiver; and a signal injection apparatus, to inject an excitation signal directly into the lower one of the portions to induce a magnetic field into a geological formation surrounding the lower one of the portions, wherein a ranging signal corresponding to the magnetic field is to be received by the signal receiver.

20 . The system of claim 19 , wherein the signal receiver comprises a magnetometer, a coil antenna, or a telemetry receiver.

21 . The system of claim 19 , wherein the second well comprises a drilling well, wherein the signal injection apparatus comprises a power supply coupled to a ground point that is less than 100 m from an opening of the first well in a surface of the Earth, and wherein the excitation signal comprises a current.

Assignees

• Halliburton Energy Services Inc

Inventors

• Wu Hsu-Hsiang
• Parakash Anand
• Fan Yijing

Classifications

• G01V3/26 Primary

  operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device (with electromagnetic waves G01V3/30) · CPC title

• E21B47/00

  Survey of boreholes or wells (monitoring pressure or flow of drilling fluid E21B21/08) · CPC title

• E21B47/02

  Determining slope or direction · CPC title

• G01V3/081 Primary

  the magnetic field is produced by the objects or geological structures (characterised by the method of magnetic field measurement G01R33/00) · CPC title

• E21B47/022 Primary

  of the borehole, e.g. using geomagnetism · CPC title