CASING MOUNTED EM TRANSDUCERS HAVING A SOFT MAGNETIC LAYER

• US 20150137817A1
• Filed: 11/18/2013
• Published: 05/21/2015
• Est. Priority Date: 11/18/2013
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Donderici, Burkay, WILSON, Glenn A.
• Granted Patent: US 9,513,398 B2
• Time in Patent Office: Days
• US Class Current: 324/333
• CPC Class Codes: E21B 43/10 Setting of casings, screens, liners or the like in wells
• CPC Class Codes: E21B 43/12 Methods or apparatus for controlling the flow of the obtained fluid to or in wells E21B43/25 takes precedence; valve arrangements E21B34/00
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/092 by detecting magnetic anomalies
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: G01V 3/28 using induction coils

Abstract

Illustrative permanent electromagnetic (EM) monitoring systems and methods have a casing string positioned inside a borehole and equipped with one or more EM transducer modules having a layer of soft magnetic material that substantially encircles the casing string to amplify a signal response of a magnetic field transmitting and/or sensing element. The layer preferably has an axial dimension at least twice an axial dimension of the magnetic field sensing element, with a relative permeability at least twice that of the casing material. The magnetic field transmitting element can be a coil. The magnetic field sensing element can be a coil or a piezoelectric or magnetostrictive element that applies stress to an optical fiber. A well interface system communicates with the one or more EM transducer modules to transmit and/or collect EM signals over time. Additional casing strings may be provided in other nearby boreholes to enable tomographic mapping and monitoring of fluid interfaces in the reservoir.

Claims

1. A permanent electromagnetic (EM) monitoring system that comprises:

a casing string positioned inside a borehole, the casing string having at least one EM transducer module that includes;

a wire coil that encircles the casing string; and

a layer of soft magnetic material between the coil and the casing string; and

a well interface system coupled to the at least one EM transducer module to transmit and/or collect EM signals over time.

2. The system of claim 1, wherein the casing string includes multiple EM transducer modules.

3. The system of claim 2, further comprising:

a second casing string positioned inside a second borehole and having at least one EM transducer module; and

a second well interface system coupled to the at least one EM transducer module in the second borehole to collect and/or transmit EM signals over time.

4. The system of claim 3, further comprising a computer that receives measurements from each of said well interface systems, wherein the computer images and/or inverts said measurements to monitor at least one parameter of the subsurface formation over time.

5. The system of claim 4, wherein said at least one parameter includes fluid saturation.

6. The system of claim 1, wherein said layer has an axial dimension at least twice an axial dimension of the wire coil.

7. The system of claim 1, wherein said layer has a thickness between 1 mm and 15 mm.

8. The system of claim 1, wherein said layer has a relative permeability of at least 200 and a conductivity of less than 1 S/m.

9. The system of claim 1, wherein the at least one EM transducer module is a self-contained unit that communicates wirelessly with the well interface system.

10. The system of claim 1, wherein the at least one EM transducer module further includes a connector for a wired connection to the well interface system.

11. The system of claim 1, wherein said layer is created in a recess on an exterior surface of a casing tubular.

12. The system of claim 1, wherein said layer is integral to a module body that slips over a casing tubular.

13. A permanent electromagnetic (EM) monitoring method that comprises:

running a casing string into a borehole, the casing string including at least one EM transducer module with a layer of soft magnetic material underlying a wire coil that encircles the casing string;

establishing communication between a well interface system and the at least one EM transducer module; and

employing the at least one EM transducer module to transmit and/or collect EM signals over time.

14. The method of claim 13, further comprising cementing the casing string in place.

15. The method of claim 13, further comprising imaging and/or inverting said EM signals to monitor at least one parameter of the subsurface formation over time.

16. The method of claim 15, wherein said parameter is fluid saturation.

17. A permanent electromagnetic (EM) monitoring system that comprises:

a casing string positioned inside a borehole, the casing string having at least one EM transducer module that includes;

a magnetic field sensing element; and

a layer of soft magnetic material that substantially encircles the casing string to amplify a signal response of the magnetic field sensing element; and

a well interface system coupled to the at least one EM transducer module to collect EM signals over time.

18. The system of claim 17, further comprising an optical fiber that couples the magnetic field sensing element to the well interface system.

19. The system of claim 18, wherein the magnetic field sensing element is a piezoelectric or magnetostrictive material that modulates a strain in said optical fiber to represent a received EM signal.

20. A permanent electromagnetic (EM) monitoring method that comprises:

running a casing string into a borehole, the casing string including at least one EM transducer module with a magnetic field sending element and a layer of soft magnetic material that substantially encircles the casing string to amplify a signal response of the magnetic field sensing element;

establishing communication between a well interface system and the at least one EM transducer module; and

employing the at least one EM transducer module to collect EM signals over time.

21. The method of claim 20, further comprising cementing the casing string in place.

22. The method of claim 20, further comprising imaging and/or inverting said EM signals to monitor at least one parameter of the subsurface formation over time.

23. The method of claim 22, wherein said parameter is fluid saturation.