Method of estimating anisotropic formation resistivity profile using a multi-component induction tool

Patent metadata

Field	Value
Publication number	US-10416336-B2
Application number	US-201214409931-A
Country	US
Kind code	B2
Filing date	Jul 13, 2012
Priority date	Jul 13, 2012
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

Improved algorithm for estimating anisotropic formation resistivity profile using a multi-component induction tool are disclosed. A method for estimating anisotropic formation resistivity profile of a formation comprises obtaining borehole corrected log data and determining at an azimuth angle of the formation. One or more formation bed boundaries are located and initial formation properties are calculated. One of a plurality of inversion windows is sequentially selected and a one-dimensional inversion of each of the sequentially selected one of the plurality of inversion windows is performed.

First claim

What is claimed is:

1. A method for estimating anisotropic formation resistivity profile of a formation comprising:
exciting a transmitter of a logging tool;
receiving one or more measurements from a receiver of the logging tool, wherein the one or more measurements are based on the excitation of the transmitter;
determining an azimuth angle of the formation based on the one or more measurements;
locating one or more initial formation bed boundaries of the formation;
calculating initial formation properties based on one or more selected logging points of the one or more measurements, wherein the one or more selected logging points sit at a middle of each of the one or more initial formation bed boundaries, wherein the initial formation properties comprise at least an initial dipping angle, an initial horizontal conductivity and an initial vertical conductivity;
sequentially selecting each one of a plurality of inversion windows, each inversion window comprising one or more formation layers modelled therein, wherein each inversion window comprises at least one formation layer of the one or more formation layers in common with one other inversion window; and
performing a one-dimensional inversion of each of the sequentially selected one of the plurality of inversion windows until the one or more formation layers for each plurality of inversion windows have been finally modelled, wherein a first one of the one-dimensional inversion is based on the initial formation properties, and wherein each subsequent one of the one-dimensional inversion is based on at least one previous one of the one-dimensional inversion;
determining one or more formation properties for the one or more layers, one or more formation bed boundaries within the one or more layers, and a relative dipping angle for each plurality of inversion windows based on the one-dimensional inversion; and
estimating an anisotropic formation resistivity profile based on the one or more formation properties, the one or more formation bed boundaries and the relative dipping angle for each plurality of inversion windows based on the one-dimensional inversion.

2. The method of claim 1 , further comprising obtaining borehole corrected log data, wherein obtaining borehole corrected log data comprises directing the logging tool to a desired location in a wellbore and obtaining the one or more measurements.

3. The method of claim 2 , wherein at least one of obtaining borehole corrected log data, determining the at least one of the azimuth angle of the formation, determining the one or more formation bed boundaries, calculating the initial formation properties, sequentially selecting the one of the plurality of inversion windows, and performing the one-dimensional inversion of each of the sequentially selected one of the plurality of inversion windows is performed using an information handling system.

4. The method of claim 1 , wherein determining the one or more formation bed boundaries comprises using a variance based method.

5. The method of claim 4 , wherein the variance based method comprises:
computing a variance value for the borehole corrected log data;
determining a variance curve for the borehole corrected log data; and
using the variance curve to locate the one or more formation bed boundaries.

6. The method of claim 5 , wherein the location of the one or more formation bed boundaries is determined based on one or more peak positions of the variance curve.

7. The method of claim 1 , wherein at least one of Levenberg-Marquardt algorithm and Broyden's method are used to perform the one-dimensional inversion of each of the sequentially selected one of the plurality of inversion windows.

8. An information handling system having a computer-readable medium containing machine readable instructions to:
receive one or more measurements from a receiver of a logging tool disposed in a borehole of a formation, wherein the one or more measurements are based on an excitation of a transmitter of the logging tool;
determine an azimuth angle of the formation based on the one or more measurements;
locate one or more initial formation bed boundaries;
calculate initial formation properties based on one or more selected logging points of the one or more measurements, wherein the one or more selected logging points sit at a middle of each of the one or more initial formation bed boundaries, wherein the initial formation properties comprise at least an initial dipping angle, an initial horizontal conductivity and an initial vertical conductivity;
sequentially select each one of a plurality of inversion windows, each inversion window comprising one or more formation layers modelled therein, wherein each inversion window comprises at least one formation layer of the one or more formation layers in common with one other inversion window; and
perform a one-dimensional inversion of each of the sequentially selected one of the plurality of inversion windows until the one or more formation layers for each plurality of inversion windows have been finally modelled, wherein a first one of the one-dimensional inversion is based on the initial formation properties, and wherein each subsequent one of the one-dimensional inversion is based on at least one previous one of the one-dimensional inversion;
determining one or more formation properties for the one or more layers, one or more formation bed boundaries within the one or more layers, and a relative dipping angle for each plurality of inversion windows based on the one-dimensional inversion; and
estimate an anisotropic formation resistivity profile based on the one or more formation properties, the one or more formation bed boundaries and the relative dipping angle for each plurality of inversion windows based on the one-dimensional inversion.

9. The information handling system of claim 8 , wherein the computer-readable medium further contains machine readable instructions to obtain borehole corrected log data, wherein obtaining borehole corrected log data comprises directing the logging tool to a desired location in the borehole and obtaining the one or more measurements.

10. The information handling system of claim 8 , wherein determining the one or more formation bed boundaries comprises using a variance based method.

11. The information handling system of claim 10 , wherein the variance based method comprises:
computing a variance value for the borehole corrected log data;
determining a variance curve for the borehole corrected log data; and
using the variance curve to locate the one or more formation bed boundaries.

12. The information handling system of claim 11 , wherein the location of the one or more formation bed boundaries is determined based on one or more peak positions of the variance curve.

13. The information handling system of claim 8 , wherein at least one of Levenberg-Marquardt algorithm and Broyden's method are used to perform the one-dimensional inversion of each of the sequentially selected one of the plurality of inversion windows.

14. A method for determining one or more parameters of a formation comprising:
placing a logging tool at a desired location in the formation;
exciting a transmitter of the logging tool;
receiving one or more measurements from a receiver of the logging tool, wherein the one or more measurements are based on the excitation of the transmitter;
determining an azimuth angle of the formation using the one or more measurements;
determining one or more initial boundary positions of the formation;
calculating one or more initial formation parameters based on one or more selected logging points of

Assignees

• Li Shanjun
• Wu Dagang
• San Martin Luis E
• Tang Yumei
• Halliburton Energy Services Inc

Inventors

• Li Shanjun
• Wu Dagang
• San Martin Luis E
• Tang Yumei

Classifications

• G01V3/18 Primary

  specially adapted for well-logging · CPC title

• G01V3/34

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

• G01V3/28 Primary

  using induction coils · CPC title

• G01V3/38

  Processing data, e.g. for analysis, for interpretation, for correction · CPC title

• E21B49/00

  Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells · CPC title