Protective barriers for small devices

• US 20070062695A1
• Filed: 09/19/2005
• Published: 03/22/2007
• Est. Priority Date: 09/19/2005
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Donzier, Eric, Harrison, Christopher, Mullins, Oliver, Vancauwenberghe, Olivier
• Granted Patent: US 7,673,679 B2
• Time in Patent Office: Days
• US Class Current: 166/250.110
• CPC Class Codes: E21B 47/017 Protecting measuring instruments
• CPC Class Codes: E21B 47/10 Locating fluid leaks, intrusions or movements
• CPC Class Codes: E21B 49/10 using side-wall fluid samplers or testers

Abstract

Protective barriers for small devices, such as sensors, actuators, flow control devices, among others, protect the devices from erosive and/or corrosive fluids, for example, formation fluids under harsh downhole conditions. The protective barriers include protective coatings and fluid diverting structures in the fluid flow which facilitate use of the small devices in high temperature-high pressure applications with erosive and/or corrosive fluids that are often found in downhole environments.

Claims

1. A downhole fluids analysis system, comprising:

a small device adapted for downhole use to measure a property of a flowing fluid in contact with the device; and

a protective barrier for protecting the device against the fluid.

2. The downhole fluids analysis system claimed in claim 1, wherein

the protective barrier protects against at least one of erosion and corrosion by the fluid.

3. The downhole fluids analysis system claimed in claim 2, wherein

the protective barrier comprises a coating on the device.

4. The downhole fluids analysis system claimed in claim 3, wherein

the coating is selected from the group consisting of tantalum, tungsten, titanium, silicon, boron, aluminum, chromium, and their oxides, carbides and nitrides.

5. The downhole fluids analysis system claimed in claim 4, wherein

the coating is selected from the group consisting of silicon carbide, boron nitride, boron carbide, tungsten carbide, chromium nitride, titanium nitride, silicon nitride, titanium carbide, tantalum carbide, tungsten, titanium, aluminum nitride, tantalum oxide, silicon carbide and titanium oxide.

6. The downhole fluids analysis system claimed in claim 3, wherein

the coating comprises titanium nitride.

7. The downhole fluids analysis system claimed in claim 3, wherein

the coating comprises tantalum oxide.

8. The downhole fluids analysis system claimed in claim 3, wherein

the coating comprises an anti-adhesion layer as an outer layer of the coating on the device.

9. The downhole fluids analysis system claimed in claim 1, wherein

the protective barrier comprises two or more layers of coating on the device.

10. The downhole fluids analysis system claimed in claim 9, wherein

the two or more layers of coating are selected from the group consisting of tantalum, tungsten, titanium, silicon, boron, aluminum, chromium, and their oxides, carbides and nitrides.

11. The downhole fluids analysis system claimed in claim 10, wherein

the two or more layers of coating are selected from the group consisting of silicon carbide, boron nitride, boron carbide, tungsten carbide, chromium nitride, titanium nitride, silicon nitride, titanium carbide, tantalum carbide, tungsten, titanium, aluminum nitride, tantalum oxide, silicon carbide and titanium oxide.

12. The downhole fluids analysis system claimed in claim 9, wherein

the protective barrier comprises a first layer of tantalum oxide and a second layer of titanium nitride.

13. The downhole fluids analysis system claimed in claim 12, wherein

the tantalum oxide layer protects against corrosion and the titanium nitride layer protects against erosion, the titanium nitride layer being over the tantalum oxide layer.

14. The downhole fluids analysis system claimed in claim 13, wherein

the protective barrier further comprises:

an anti-adhesion layer over the titanium nitride layer.

15. The downhole fluids analysis system claimed in claim 12, wherein

the protective barrier further comprises:

an anti-adhesion layer as an outer layer on the device.

16. The downhole fluids analysis system claimed in claim 1, wherein

the protective barrier comprises a baffle device for deflecting particulate laden flow away from the device.

17. The downhole fluids analysis system claimed in claim 16, wherein

the protective barrier further comprises:

at least one coating on the device.

18. The downhole fluids analysis system claimed in claim 17, wherein

the at least one coating is selected from the group consisting of tantalum, tungsten, titanium, silicon, boron, aluminum, chromium, and their oxides, carbides and nitrides.

19. The downhole fluids analysis system claimed in claim 18, wherein

the at least one coating is selected from the group consisting of silicon carbide, boron nitride, boron carbide, tungsten carbide, chromium nitride, titanium nitride, silicon nitride, titanium carbide, tantalum carbide, tungsten, titanium, aluminum nitride, tantalum oxide, silicon carbide and titanium oxide.

20. The downhole fluids analysis system claimed in claim 16, wherein

the protective barrier further comprises:

a tantalum oxide layer on the device for protecting the device against corrosion and a titanium nitride layer on the device for protecting the device against erosion, the titanium nitride layer being over the tantalum oxide layer.

21. A tool adapted to be movable through a borehole that traverses an earth formation, comprising:

a fluid admitting assembly for extracting a fluid from the earth formation into the tool;

a small device arranged to be in fluid contact with the fluid in the tool to determine a fluid property; and

a protective barrier associated with the small device for shielding the device against corrosion and erosion by the fluid.

22. A device having applications in high temperature, high pressure environments, comprising:

a portion for exposure to high temperature, high pressure subterranean fluids that are at least one of erosive and corrosive in nature; and

a protective barrier associated with the device for protecting the exposed portion of the device against at least one of erosion and corrosion by the fluids.

23. The device claimed in claim 22, wherein

the device comprises a MEMS sensor for downhole applications.

24. A method of downhole fluid analysis, comprising:

establishing fluid communication between a downhole device, adapted for measuring fluid properties under high temperature, high pressure conditions, and subterranean formation fluids in a borehole; and

providing at least one protective barrier associated with the downhole device for protecting the downhole device against at least one of erosion and corrosion by the formation fluids.