Processing and geosteering with a rotating tool

Patent metadata

Field	Value
Publication number	US-9791586-B2
Application number	US-201013502571-A
Country	US
Kind code	B2
Filing date	Apr 15, 2010
Priority date	Apr 15, 2010
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Various embodiments include apparatus and methods of processing and geosteering with respect to well logging. Apparatus and methods may include acquiring signals generated from operating a tool rotating in a borehole of a well, where the tool includes a receiver antenna tilted with respect to the longitudinal axis of the tool and two transmitter antennas. The acquired signals can be processed with respect to a direction in the rotation of the tool to determine properties associated with a formation and/or to determine a geosignal for geosteering a drilling operation.

First claim

What is claimed is:

1. A method of determining properties of a formation surrounding a borehole in which a tool coupled to a drilling tool is operating, the method comprising:
acquiring signals generated from operating the tool rotating in the borehole, the tool having a longitudinal axis, the tool including two transmitter antennas and a receiver antenna tilted with respect to the longitudinal axis, the two transmitter antennas being oriented within different adjacent quadrants with respect to the longitudinal axis, the acquired signals including signals received at the tilted receiver antenna in response to firing separately the two transmitter antennas associated with the tilted receiver antenna; and
operating a processing unit to process the acquired signals with respect to a direction relative to the rotation of the tool to determine properties associated with the formation, including determining a coupling matrix by determining a plurality of coupling voltage components directly from the acquired signals, based on the two transmitter antennas being oriented in adjacent quadrants, by directly calculating each of the plurality of coupling voltage components from the acquired signals measured at rotated positions of the tool, and the position and orientation of the tool without solving a set of equations relating the acquired signals to the coupling voltage components;
determining a geosignal from the coupling matrix; and
utilizing the geosignal to control a drilling direction of the drilling tool.

2. The method of claim 1 , wherein acquiring signals includes acquiring voltage signals generated from operating the tool with the receiver antenna tilted with respect to the longitudinal axis and the two transmitter antennas placed essentially at the same location.

3. The method of claim 1 , wherein acquiring signals includes acquiring voltage signals generated from operating the tool with the receiver antenna tilted with respect to the longitudinal axis such that the tilted receiver antenna is placed between the two transmitter antennas.

4. The method of claim 1 , wherein acquiring signals includes acquiring voltage signals generated from operating the tool with the receiver antenna tilted with respect to the longitudinal axis and with another receiver antenna tilted with respect to the longitudinal axis and with the two receiver antennas placed between the two transmitter antennas.

5. The method of claim 4 , wherein the method includes generating two coupling voltage matrices from received voltage signals at the two tilted receiver antennas.

6. The method of claim 4 , wherein, with respect to the longitudinal axis, one of the two transmitter antennas is tilted at 45 degrees and the other transmitter antenna is tilted at −45 degrees and the two receiver antennas are tilted at an angle of 45 degrees.

7. The method of claim 4 , wherein acquiring signals includes:
firing one of the two transmitter antennas and measuring a response at the tilted receiver antenna with respect to the firing;
firing the other transmitter antenna and measuring a response at the other tilted receiver antenna with respect to the firing of the other transmitter antenna; and
calculating coupling voltage components for a coupling matrix using the measured responses received at the two tilted receivers with respect to tool position and tool orientation; and
performing one or more inversion operations to generate formation parameters from the coupling matrix.

8. The method of claim 7 , wherein the method includes determining horizontal resistivity, vertical resistivity, relative dip angle, or combinations thereof from the coupling matrix.

9. The method of claim 1 , wherein acquiring signals includes acquiring voltage signals with respect to tool orientation, the tool orientation including a number of directions, the total number of directions corresponding one complete rotation partitioned into N bins, each bin associated with an angle of rotation equal to 2π/N, N being an integer equal to or greater than one.

10. The method of claim 1 , wherein acquiring signals includes acquiring voltage signals generated from operating the tool rotating in the borehole with the receiver antenna operated as a transmitting antenna and the two transmitter antennas tilted and operated as receiver antennas.

11. The method of claim 1 , wherein the two transmitter antennas and the receiver antenna tilted with respect to the longitudinal axis is an arrangement of antennas based on criteria to arrange the antennas, wherein the criteria enables the direct determination of the coupling matrix.

12. A method of determining properties of a formation surrounding a borehole in which a tool is operating, the method comprising:
acquiring signals generated from operating a tool rotating in the borehole, the tool having a longitudinal axis, the tool including a receiver antenna tilted with respect to the longitudinal axis and two transmitter antennas, the two transmitter antennas being oriented within different adjacent quadrants with respect to the longitudinal axis, the acquired signals including signals received at the tilted receiver antenna in response to firing separately the two transmitter antennas associated with the tilted receiver antenna; and
operating a processing unit to process the acquired signals with respect to a direction in the rotation of the tool to determine properties associated with a formation, including determining a geosignal response, directly from the acquired signals based on the two transmitter antennas being oriented within different adjacent quadrants with respect to the longitudinal axis, by generating the geosignal response as a ratio of a received signal at an azimuthal angle to a received signal at the azimuthal angle plus 180°.

13. The method of claim 12 , wherein the method includes geosteering of a drill operation based on the geosignal response.

14. The method of claim 12 , wherein determining a geosignal response from the acquired signals includes generating the geosignal response as a geosignal phase and a geosignal attenuation.

15. The method of claim 14 , wherein the method includes:
partitioning the tool rotation into N bins in which completion of the N bins is one complete rotation, N≦2;
generating, for a bin, the geosignal phase as the difference between a phase of a voltage signal received at the tilted receiver antenna in response to firing one transmitter antenna for the bin and a phase of a voltage signal received at the tilted receiver antenna in response to firing the one transmitter antenna at another bin that is 180 degrees from the bin; and
generating, for the bin, the geosignal attenuation as the difference between the log of the voltage signal received at the tilted receiver antenna in response to firing the one transmitter antenna for the bin and the log of the voltage signal received at the tilted receiver antenna in response to firing the one transmitter antenna at another bin that is 180 degrees from the bin.

16. A method comprising:
acquiring signals generated from operating a tool rotating in a borehole, the tool having a longitudinal axis, the tool including a receiver antenna tilted with respect to the longitudinal axis and two transmitter antennas, the acquired signals including signals received at the tilted receiver antenna in response to firing separately the two transmitter antennas associated with the tilted receiver antenna; and
operating a processing unit to process the acquired signals with respect to a direction in the rotation of the tool to determine properties associated with a for

Assignees

• Bittar Michael S
• Wu Hsu-Hsiang
• Li Shanjun
• Halliburton Energy Services Inc

Inventors

• Bittar Michael S
• Wu Hsu-Hsiang
• Li Shanjun

Classifications

• G01V3/28 Primary

  using induction coils · CPC title

• E21B47/026

  of penetrated ground layers · CPC title