Formation property measurement apparatus, methods, and systems

Patent metadata

Field	Value
Publication number	US-10429459-B2
Application number	US-201515564627-A
Country	US
Kind code	B2
Filing date	Apr 16, 2015
Priority date	Apr 16, 2015
Publication date	Oct 1, 2019
Grant date	Oct 1, 2019

Abstract

In some embodiments, an apparatus and a system, as well as methods, may include operating a transmitting antenna and a receiving antenna as equivalent tilted dipoles, wherein the tilted dipoles provide a selection of equivalent tilt angles for at least one of the transmitting antenna or the receiving antenna. Further activity may comprise receiving signals by the receiving antenna disposed in a geological formation, the signals to be inverted to obtain at least one of resistivity or dielectric constant properties of the geological formation at a selected depth of investigation, the depth determined by the selection of the equivalent tilt angles and weighting with pre-computed integrated radial sensitivity signal data. Additional methods, apparatus, and systems are disclosed.

First claim

What is claimed is:

1. An apparatus, comprising:
at least a transmitting antenna and a receiving antenna of a downhole tool housing, wherein the transmitting antenna and receiving antenna are steerable to provide equivalent dipoles with a selected tilt angle of a plurality of tilt angles with respect to a longitudinal axis of the downhole tool housing; and
a controller to select the selected tilt angle of the transmitting antenna and the receiving antenna, to enable acquisition of signal data by the receiving antenna corresponding to a selected depth of investigation for resistivity and dielectric constant in a geological formation.

2. The apparatus of claim 1 , wherein the transmitting antenna and the receiving antenna are synchronously steerable.

3. The apparatus of claim 1 , wherein the transmitting antenna and the receiving antenna are electrically steerable.

4. The apparatus of claim 1 , further comprising:
a memory accessible by the controller, the memory to store a look-up table of measurement data weights corresponding to the selected tilt angle and the selected depth of investigation.

5. The apparatus of claim 1 , wherein the transmitting antenna comprises a multi-feed cavity antenna.

6. A system, comprising:
a downhole tool housing having a longitudinal axis;
at least a transmitting antenna and a receiving antenna attached to the housing, the transmitting antenna and the receiving antenna synchronously steerable to provide an equivalent dipole array with a selected tilt angle of a plurality of tilt angles with respect to the longitudinal axis of the downhole tool housing; and
a controller to select the selected tilt angle, to enable acquisition of signal data by the receiving antenna corresponding to a selected depth of investigation for at least one physical property in a geological formation in which the housing is disposed.

7. The system of claim 6 , wherein at least one of the transmitting antenna or the receiving antenna comprise a cross-feed, square cavity antenna or circular cavity antenna.

8. The system of claim 6 , wherein the downhole tool housing comprises one of a wireline tool housing or a drill string tool housing.

9. The system of claim 6 , further comprising:
a memory accessible by the controller, the memory to store a look-up table of measurement data weights corresponding to the selected tilt angle and the selected depth of investigation.

10. A method comprising:
operating at least a transmitting antenna and a receiving antenna as equivalent tilted dipoles, wherein the tilted dipoles provide a selection of equivalent tilt angles for at least one of the transmitting antenna or the receiving antenna; and
receiving signals by the receiving antenna disposed in a geological formation, the signals to be inverted to obtain at least one of resistivity or dielectric constant properties of the geological formation at a selected depth of investigation, the depth determined by the selection of the equivalent tilt angles and weighting with pre-computed integrated radial sensitivity signal data.

11. The method of claim 10 , further comprising:
retrieving weight values corresponding to a desired integrated radial sensitivity level and the depth, to apply to the signals, producing weighted signal data.

12. The method of claim 11 , wherein the desired integrated radial sensitivity level is a maximal value.

13. The method of claim 10 , further comprising:
interpolating between weight values stored in a memory to derive weighting values corresponding to the selected depth of investigation; and
applying the weighting values to the signals, producing weighted signal data.

14. The method of claim 11 , further comprising:
inverting the weighted signal data to determine at least one of the resistivity or dielectric constant properties of the geological formation.

15. The method of claim 10 , further comprising:
determining convergence of at least one of the resistivity or dielectric properties over a range of the depth of investigation, as a measure of model quality.

16. The method of claim 10 , further comprising:
determining divergence of the at least one of the resistivity or dielectric properties over a range of the depth of investigation, as a measure of formation transition zone existence.

17. The method of claim 10 , further comprising:
selecting the depth of investigation by steering at least one of the transmitting antenna or the receiving antenna to select one of the equivalent tilt angles.

18. The method of claim 10 , further comprising:
applying weight values corresponding to a desired integrated radial sensitivity level and the depth, to maintain the desired integrated sensitivity level across more than one formation type.

19. A method, comprising:
simulating operation of a tilted dipole antenna array in a simulated geological formation to obtain simulated signals over a predetermined range of equivalent magnetic dipole tilt angles and properties of the geological formation;
determining integrated radial sensitivity of the array with respect to the range of equivalent magnetic dipole tilt angles;
determining weight values corresponding to the range of equivalent magnetic dipole tilt angles and a desired depth of investigation; and
storing the weight values in a memory, to enable dynamic control of depth of investigation with respect to measuring resistivity or dielectric constant for a real geological formation upon access to and application of the weight values to real signals received by one or more real receiver antennas disposed in a real geological formation to generate weighted averaged values.

20. The method of claim 19 , further comprising:
repeating the simulating, determining the integrated radial sensitivity of the array, and determining the weighted average values over a range of depths of investigation.

21. The method of claim 19 , wherein determining the weighted average values comprises:
selecting the weighted average values to provide a maximal value for the integrated radial sensitivity at the desired depth of investigation.

Assignees

• Halliburton Energy Services Inc

Inventors

• Ewe Wei-Bin
• Donderici Burkay
• Wilson Glenn A
• San Martin Luis Emilio

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

• G01R33/4831

  using B1 gradients, e.g. rotating frame techniques, use of surface coils · CPC title

• G01R33/44

  using nuclear magnetic resonance [NMR] (G01R33/24, G01R33/62 take precedence) · CPC title

• G01R33/3415 Primary

  comprising arrays of sub-coils {, i.e. phased-array coils with flexible receiver channels} · CPC title

• E21B47/123

  Fixed Constructions · mapped topic