Title of Invention

" A METHOD OF DETERMINING A RESISTIVITY OF AN ANISOTROPIC EARTH FORMATION"

Abstract A method is disclosed for real-time (well-site) resistivity anisotropy determination using array lateral logs or any other unfocused, lateral-type measurements, and array induction logs or any other focused, induction-type measurements. Near-vertical wells with a deviation angle of less than 30 degrees are considered. Since with a lateral log, at each logging depth the injected current has both horizontal and vertical components, the data contains information related to both horizontal (Rh) and vertical (Rv) resistivities. With array induction tool, the induced current in near-vertical wells has only a horizontal component, and the induction data contain information related to Rh only. Having those two data sets acquired in the same well, i...
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WE CLAIM:
1. A method of determining a resistivity of an anisotropic earth
formation, the method comprising:
(a) obtaining a plurality of differential array resistivity
measurement (511);
(b) obtaining a plurality of induction resistivity measurements
(511); and
(c) processing (513, 515, 517) said plurality of unfocused
differential array resistivity measurements and said plurality
of induction resistivity measurements and obtaining
therefrom the resistivity, said processing excluding an
inversion of said induction log;
the method characterized by:
(d) the differential array resistivity measurements comprise
unfocused measurements (lateral log).
2. The method as claimed in claim 1, wherein the resistivity comprises a
mean resistivity of the earth formation.
3. The method as claimed in claim 1, wherein the resistivity
comprises a vertical resistivity of the earth formation.
4. The method as claimed in claim 1, wherein the resistivity comprises a
horizontal resistivity of said earth formation.
5. The method as claimed in claim 1, wherein the plurality of induction
measurements comprises focused measurements.
6. The method as claimed in claim 1, wherein the processing further
comprises applying a borehole correction and an invasion correction to
the lateral log.
7. The method as claimed in claim 1, wherein the processing further
comprises applying a borehole correction and an invasion correction to
the induction log and obtaining a horizontal resistivity.
8. The method as claimed in claim 7, wherein determining an anisotropy
factor from a vertical resistivity and the horizontal resistivity.
9. The method as claimed in claim 1, wherein making measurements
with a micro-laterolog and using said micro-laterolog measurements in
said processing.
10. The method as claimed in claim 1, wherein step (a), (b) and (c) are
performed using:
(a) an unfocused differential array resistivity measuring device
configured to obtain the plurality of unfocused differential
array resistivity measurements (lateral log);
(b) an induction resistivity measuring device configured to
obtain the plurality of induction resistivity measurements;
(c) a processor configured to process the plurality of unfocused
differential array resistivity measurements and the plurality
of induction resistivity measurements and estimates
therefrom the parameter of interest, the processing
excluding an inversion of the induction log.
11. The method as claimed in claim 10, wherein the processor is
configured to estimate, the parameter of interest, a vertical
resistivity of said earth formation.

12. The method as claimed in claim 10, wherein the processor is configured to estimate, as the parameter of interest, a horizontal resistivity of said earth formation.
13. The method as claimed in claim 10, wherein the induction
resistivity measuring device is configured to obtain, as the
plurality of induction measurements, focused measurements.
14. The method as claimed in claim 10, wherein the processor is
configured to apply a borehole correction and an invasion
correction to the lateral log.
15. The method as claimed in claim 14, wherein the processor is
configured to apply a borehole correction and an invasion
correction to said induction log and obtain a horizontal resistivity.
16. The method as claimed in claim 15, wherein the processor is
configured to determine the anisotropy factor from the vertical
resistivity and the horizontal resistivity.
17. The method as claimed in claim 10, wherein the processor is
configured to use the micro-laterolog in the processing.
18. The method as claimed in claim 10, wherein a processor is
configured to perform said processing in real time
19. The method as claimed in claim 10, wherein a processor is at a surface location.
20 The method as claimed in claim 10, wherein the processor is at a downhole location.
21. The method as claimed in claim 10, wherein an induction
resistivity device is an array device.
22. The method as claimed in claim 10, wherein an induction
resistivity device having a plurality of coils with an axis parallel to
an axis of said induction resistivity device.
23. The method as claimed in claim 10, wherein:
(i) as the unfocused differential array resistivity device, an unfocused differential array resistivity measuring device configured to be conveyed into the borehole using a conveyance device, and
(ii) as the induction resistivity device, an induction resistivity device
configured to be conveyed into the borehole using the conveya.

Documents:

1183-delnp-2005-abstract.pdf

1183-delnp-2005-claims.pdf

1183-delnp-2005-complete specification (granted).pdf

1183-DELNP-2005-Correspondence-Others-(24-09-2009).pdf

1183-delnp-2005-correspondence-others.pdf

1183-delnp-2005-correspondence-po.pdf

1183-delnp-2005-description (complete).pdf

1183-delnp-2005-drawings.pdf

1183-delnp-2005-form-1.pdf

1183-delnp-2005-form-18.pdf

1183-delnp-2005-form-2.pdf

1183-DELNP-2005-Form-3-(24-09-2009).pdf

1183-delnp-2005-form-3.pdf

1183-delnp-2005-form-5.pdf

1183-delnp-2005-gpa.pdf

1183-delnp-2005-pct-409.pdf

1183-delnp-2005-petition-137.pdf

1183-delnp-2005-petition-138.pdf


Patent Number 241542
Indian Patent Application Number 1183/DELNP/2005
PG Journal Number 29/2010
Publication Date 16-Jul-2010
Grant Date 12-Jul-2010
Date of Filing 24-Mar-2005
Name of Patentee BAKER HUGHES INCORPORATED
Applicant Address 3900 ESSEX LANE, SUITE 1200, HOUSTON,TX 77027, UNITED STATES OF AMERICA
Inventors:
# Inventor's Name Inventor's Address
1 INGO M GELDMACHER 20922 MANON LANE,SPRING TX 77388, USA
2 MICHAEL A FRENKEL 1130PENNBURY DRIVE, HOUSTON, TX 77094, USA
PCT International Classification Number G01V 3/20
PCT International Application Number PCT/US2003/030440
PCT International Filing date 2003-09-26
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/414174 2002-09-27 U.S.A.