System and methods for evaluating a formation using pixelated solutions of formation data

Patent metadata

Field	Value
Publication number	US-11525353-B2
Application number	US-201715773511-A
Country	US
Kind code	B2
Filing date	May 8, 2017
Priority date	May 8, 2017
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A system and method for evaluating a subterranean earth formation as well as a method of steering a drill bit in a subterranean earth formation. The system comprises a logging tool that is operable to measure formation data and locatable in a wellbore intersecting the subterranean earth formation. The system also comprises a processor that is in communication with the logging tool. The processor is operable to calculate multiple distance-to-bed-boundary (DTBB) solutions using the measured formation data, identify DTBB solutions that satisfy a threshold, convert the identified solutions into pixelated solutions by dividing the identified solutions into pixels, generate a formation model based on the pixelated solutions, and evaluate the formation using the generated formation model.

First claim

What is claimed is:

1. A system for evaluating a subterranean earth formation, comprising:
a logging tool locatable in a wellbore intersecting the subterranean earth formation and operable to measure formation data at different measurement depths along the wellbore; and
a processor in communication with the logging tool and operable to:
generate multiple distance-to-bed-boundary (DTBB) solutions at a measurement depth using a DTBB inversion method with the measured formation data for the measurement depth,
identify the DTBB solutions that satisfy a residual threshold relative to the measured formation data,
convert only the identified solutions into pixelated solutions by dividing the identified solutions into pixels,
generate a formation model based on the pixelated solutions, and
evaluate the formation using the generated formation model.

2. The system of claim 1 , wherein the logging tool comprises a resistivity logging tool operable to measure the resistivity of the formation.

3. The system of claim 1 , wherein the processor is further operable determine an uncertainty of a parameter from the measured formation data based on the pixelated solutions.

4. The system of claim 3 , wherein the uncertainty of the parameter is determined based on the standard deviation of the parameter determined from the formation model.

5. The system of claim 3 , wherein the uncertainty of the parameter is determined based on the derivative of a horizontal resistivity determined from the formation model.

6. The system of claim 3 , wherein the parameter includes any one or any combination of a horizontal resistivity, an anisotropy ratio, a boundary position of formation layers, and a formation dip.

7. The system of claim 3 , wherein the uncertainty of the parameter is determined by applying a filter to the derivative of a horizontal resistivity derived from the formation model.

8. The system of claim 3 , wherein the uncertainty of the parameter is determined by applying a filter to a derivative of a horizontal resistivity determined from the formation model and identifying a peak width of the convoluted derivative.

9. The system of claim 1 , wherein the formation model is generated by calculating a mean of the pixelated solutions.

10. The system of claim 9 , wherein the mean is calculated by not including outlier pixels among the pixelated solutions.

11. A method of evaluating a subterranean earth formation, comprising:
measuring formation data at different measurement depths in a wellbore intersecting the subterranean earth formation using a logging tool;
transmitting the formation data to a computer system comprising a processor at the surface of the earth;
generating, with the processor, multiple distance-to-bed-boundary (DTBB) solutions at a measurement depth using a DTBB inversion method with the measured formation data for the measurement depth;
identifying, with the processor, the DTBB solutions that satisfy a residual threshold relative to the measured formation data;
converting, with the processor, only the identified solutions into pixelated solutions by dividing the identified solutions into pixels;
generating, with the processor, a formation model based on the pixelated solutions; and
evaluating the formation using the formation model.

12. The method of claim 11 , wherein the logging tool comprises a resistivity logging tool operable to measure the resistivity of the formation.

13. The method of claim 11 , further comprising determining an uncertainty of a parameter based on the formation model.

14. The method of claim 13 , wherein determining the uncertainty of the parameter comprises calculating a standard deviation of the parameter based on the formation model.

15. The method of claim 13 , wherein determining the uncertainty of the parameter comprises:
calculating a derivative of a horizontal resistivity determined from the formation model;
applying a convolution method to the derivative of the horizontal resistivity; and
identifying a peak width of the convoluted derivative, wherein the uncertainty of the parameter includes the peak width.

16. The method of claim 13 , wherein the parameter includes any one or any combination of a horizontal resistivity, an anisotropy ratio, a boundary position of formation layers, and a formation dip.

17. The method of claim 11 , wherein generating the formation model comprises calculating a mean of the pixelated resistivity solutions.

18. The method of claim 17 , wherein the mean is calculated by not including outlier pixels among the pixelated solutions from the calculation.

19. A method of steering a drill bit in a subterranean earth formation, comprising:
measuring formation data at different measurement depths in a wellbore intersecting the subterranean earth formation using a logging tool located in the wellbore;
transmitting the formation data to a computer system comprising a processor at the surface of the earth;
generating, with the processor, multiple distance-to-bed-boundary (DTBB) solutions at a measurement depth using a DTBB inversion method with the measured formation data for the measurement depth;
identifying, with the processor, the DTBB solutions that satisfy a residual threshold relative to the measured formation data;
converting, with the processor, only the identified solutions into pixelated solutions;
generating, with the processor, a formation model based on the pixelated solutions;
identifying a wellbore trajectory based on the formation model; and
steering a drill bit according to the wellbore trajectory.

20. The method of claim 19 , further comprising determining an uncertainty of a parameter of the formation based on the formation model by calculating a derivative of a horizontal resistivity derived from the formation model, applying a convolution method to the derivative of the horizontal resistivity, and identifying a peak width of the convoluted derivative, wherein the uncertainty of the parameter includes the peak width.

Assignees

• Halliburton Energy Services Inc

Inventors

• Song Rencheng
• Pan Li
• Wu Hsu-Hsiang

Classifications

• G01V3/26

  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

• E21B47/026

  of penetrated ground layers · CPC title

• G01V3/38

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

• G01V3/34

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

• E21B47/13 Primary

  by electromagnetic energy, e.g. radio frequency · CPC title