Antenna coupling component measurement tool having a rotating antenna configuration

Patent metadata

Field	Value
Publication number	US-9329298-B2
Application number	US-201514880043-A
Country	US
Kind code	B2
Filing date	Oct 9, 2015
Priority date	Dec 15, 2006
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

Disclosed herein are electromagnetic resistivity logging systems and methods that employ an antenna configuration having at most two transmitter or receiver antenna orientations that rotate relative to the borehole. The measurements made by this reduced-complexity antenna configuration enable the determination of at least seven components of a coupling matrix, which may be determined using a linear system of equations that express the azimuthal dependence of the measurements. For increased reliability, measurement averaging may be performed in azimuthally spaced bins. The coupling matrix components can then be used as the basis for determining logs of various formation parameters, including vertical resistivity and anisotropy.

First claim

What is claimed is:

1. A logging method that comprises:
receiving at least one of a set of amplitude and phase measurements as a function of azimuthal angle and tool position from a set of receivers having no more than two different receiver orientations in response to signals from a set of transmitters having no more than one transmitter orientation;
determining from said set of measurements at least seven components of a coupling matrix as a function of tool position;
finding at least one of vertical resistivity and anisotropy as a function of tool position from the coupling matrix components; and
storing said vertical resistivity or anisotropy in the form of a log.

2. The method of claim 1 , wherein said at least one of a phase and amplitude measurement is at least one of a phase difference between responses of the receiver antennas and an amplitude ratio between responses of the receiver antennas.

3. The method of claim 1 , further comprising: averaging measurements in a plurality of bins associated with different azimuthal angles.

4. The method of claim 1 , wherein said determining is performed based on a linear system of equations that express a dependence of each receiver's response on azimuthal angle.

5. The method of claim 1 , further comprising geosteering based at least in part on said vertical resistivity or anisotropy as a function of tool position.

6. The method of claim 1 , further comprising detecting a bed boundary based at least in part on said vertical resistivity or anisotropy as a function of tool position.

7. The method of claim 1 , wherein said determining, finding, and storing are performed by a downhole processor.

8. The method of claim 1 , wherein said determining, finding, and storing are performed by a surface computing facility.

9. An electromagnetic resistivity logging tool that comprises:
a rotational position sensor;
a set of receiver antennas, wherein the set of receiver antennas includes at least one receiver antenna in a first receiver orientation and at least one receiver antenna in a second receiver orientation that is different than the first receiver orientation;
a set of transmitter antennas, wherein the set of transmitter antennas includes at least one transmitter antenna in a first transmitter orientation and at least one transmitter antenna in a second transmitter orientation that is different than the first transmitter orientation;
a processor to receive at least one of a phase and amplitude measurement for each receiver antenna in the set of receiver antennas in response to signals from transmitter antennas with no more than two orientations for each of a plurality of azimuthal angles and to calculate at least one component of a coupling matrix using only receiver antennas having the first and second receiver antenna orientations.

10. The system of claim 9 , wherein the processor finds at least one of vertical resistivity and anisotropy as a function of tool position from coupling matrix components including the at least one component.

11. The system of claim 9 , wherein the processor causes said vertical resistivity or anisotropy to be stored in the form of a log.

12. The system of claim 9 , wherein said at least one of a phase and amplitude measurement is at least one of a phase difference between responses of the set of receiver antennas and an amplitude ratio between responses of the set of receiver antennas.

13. The system of claim 9 , wherein the processor averages measurements in a plurality of bins associated with different azimuthal angles.

14. The system of claim 9 , wherein the processor calculates the at least one component of a coupling matrix based on a linear system of equations that express a dependence of each receiver's response on azimuthal angle.

15. The system of claim 9 , wherein the processor determines a geosteering signal based at least in part on the at least one component of the coupling matrix.

16. The system of claim 10 , wherein the processor determines a bed boundary based at least in part on said vertical resistivity or anisotropy as a function of tool position.

Assignees

• Halliburton Energy Services Inc

Inventors

• Bittar Michael S
• Hu David Guoyu

Classifications

• E21B47/024

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

• G01B7/30

  for measuring angles or tapers; for testing the alignment of axes · CPC title

• G01V3/34

  Transmitting data to recording or processing apparatus; Recording data · CPC title

• G01V3/28 Primary

  using induction coils · CPC title