System and method for imaging properties of subterranean formations

Patent metadata

Field	Value
Publication number	US-9678239-B2
Application number	US-201414272431-A
Country	US
Kind code	B2
Filing date	May 7, 2014
Priority date	Nov 15, 2010
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A system and method for imaging properties of subterranean formations in a wellbore is provided. The system comprises a formation sensor for collecting currents injected into the subterranean formations, the formation sensor positionable on a downhole tool deployable into the wellbore. The system comprises a controller for controlling the formation sensor and a formation imaging unit. The formation imaging unit comprises a current management unit for collecting data from the currents injected into the subterranean formations, the currents having at least two different frequencies. The formation imaging unit comprises a drilling mud data unit for determining at least one drilling mud parameter, a formation data unit for determining at least one formation parameter from the collected data, and an inversion unit for determining at least one formation property by inverting the at least one formation parameter.

First claim

What is claimed is:

1. A formation imaging unit for imaging properties of at least one subterranean formation in a wellbore at a wellsite, the formation imaging unit comprising:
a current management unit for collecting data from at least two currents injected into the at least one subterranean formation, the at least two currents having at least two different frequencies;
a drilling mud data unit for determining at least one drilling mud parameter;
a formation data unit for determining at least one formation parameter from the collected data; and
an inversion unit configured to determine at least one of a drilling mud property and a formation property based on an inversion of the at least one drilling mud parameter or an inversion of the at least one formation parameter.

2. The formation imaging unit of claim 1 , wherein the inversion unit is configured to determine at least one drilling mud property and at least one formation property based on an inversion of data from the drilling mud unit or an inversion of data from the formation data unit.

3. The formation imaging unit of claim 1 , wherein the inversion unit is configured to determine at least one formation property based on an inversion of the drilling mud parameter and the at least one formation parameter.

4. The formation imaging unit of claim 3 , wherein the at least two currents comprise at least three currents.

5. The formation imaging unit of claim 3 , wherein the inversion unit is configured to determine a sensor standoff.

6. The formation imaging unit of claim 5 , wherein a sensor standoff is determined by the inversion unit using the measured borehole fluid mud property.

7. The formation imaging unit of claim 1 , wherein the drilling mud parameter is determined by measuring a borehole fluid mud property with a drilling mud sensor.

8. The formation imaging unit of claim 1 , wherein the at least two currents have a frequency range between 0.5 MHz and 100 MHz.

9. The formation imaging unit of claim 1 , further comprising a formation model unit for producing a formation model based on the at least one formation property.

10. A system for imaging properties of at least one subterranean formation in a wellbore at a wellsite, the system comprising:
a formation sensor for collecting at least two currents injected into the at least one subterranean formation, the formation sensor positionable on a downhole tool deployable into the wellbore;
a controller for controlling the formation sensor; and
a formation imaging unit, the formation imaging unit comprising:
a current management unit for collecting data from the at least two currents injected into the at least one subterranean formation, the at least two currents having at least two different frequencies;
a drilling mud data unit for determining at least one drilling mud parameter;
a formation data unit for determining at least one formation parameter from the collected data; and
an inversion unit configured to determine at least one of a drilling mud property and a formation property based on an inversion of the at least one drilling mud parameter or an inversion of the at least one formation parameter.

11. The system of claim 10 , wherein the inversion unit is configured to perform a multi-frequency parametric inversion on the at least one formation parameter.

12. The system of claim 10 , comprising a modeling unit, wherein the modeling unit is configured to construct a three-dimensional model based on the multi-frequency parametric inversion.

13. A method for imaging properties of at least one subterranean formation in a wellbore at a wellsite, the method comprising:
deploying a downhole tool into the wellbore, the downhole tool having a formation sensor thereon;
collecting at least two currents sent through the at least one subterranean formation from the formation sensor;
sending formation data from the at least two currents to a formation imaging unit, the formation imaging unit comprising:
a current management unit for collecting data from the at least two currents injected into the at least one subterranean formation, the at least two currents having at least two different frequencies;
a drilling mud data unit for determining at least one drilling mud parameter;
a formation data unit for determining at least one formation parameter from the collected data;
an inversion unit for determining at least one formation property by inverting the at least one formation parameter or the at least one drilling mud parameter; and

determining at least one formation property with the formation imaging unit.

14. The method of claim 13 , further comprising measuring a drilling mud parameter by collecting at least one current sent through a drilling mud.

15. The method of claim 14 , wherein the current sent through the drilling mud has the same frequency as the at least one of the two different frequencies.

16. The method of claim 15 , further comprising exchanging the current sent by the mud sensor substantially through the drilling mud.

17. The method of claim 16 , wherein collecting the at least two currents comprises collecting the two currents and inverting the formation parameters collected by the two currents.

18. The method of claim 17 , further comprising determining a formation resistivity by inverting the formation parameters.

19. The method of claim 13 , wherein collecting the at least two currents comprises collecting three currents and inverting the formation parameters collected by the three currents and inverting for the drilling fluid parameters.

20. The method of claim 19 , further comprising determining a formation resistivity by inverting the formation parameters, the drilling fluid parameters and a sensor standoff.

Assignees

• Schlumberger Technology Corp

Inventors

• Habashy Tarek M
• Hayman Andrew J
• Chen Yong-Hua
• Omeragic Dzevat
• Cheung Philip S

Classifications

• G01V3/24 Primary

  using AC · CPC title

• G01V3/088

  operating with electric fields (G01V3/082 takes precedence) · CPC title

• E21B49/005

  Testing the nature of borehole walls or the formation by using drilling mud or cutting data · CPC title

• G01V3/20 Primary

  operating with propagation of electric current · CPC title