Formation evaluation at drill bit

Patent metadata

Field	Value
Publication number	US-11822039-B2
Application number	US-202017769931-A
Country	US
Kind code	B2
Filing date	Oct 8, 2020
Priority date	Oct 21, 2019
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

In a drill bit which has hard-faced cutting or gauge protection elements positioned to be in direct contact with subterranean formation as the bit is rotated, at least one of these elements includes a window positioned to be in direct contact with the formation or cuttings from the formation as the bit rotates and moves forward to drill into the formation. Electromagnetic radiation with wavelength in the range from 100 nm to 2600 nm is transmitted through the window to the formation in contact with the window. Electromagnetic radiation such as fluorescence that returns through the same window is received by a spectrometer. The source and receiver of electromagnetic radiation are both accommodated within the downhole drilling equipment but spaced from the windowed element. The electromagnetic radiation travels along light guides from the source to the window and from the window to the receiver.

First claim

What is claimed is:

1. A drilling tool, comprising:
a plurality of cutting or gauge protection elements, wherein at least one cutting or gauge protection element of the plurality of cutting or gauge protection elements includes a window that is transparent to electromagnetic radiation, and which has an interior surface and a superhard exterior surface;
a drilling tool body defining a plurality of pockets which accommodate the plurality of cutting or gauge protection elements and position the plurality of cutting or gauge protection elements to be in direct contact with a subterranean formation as the drilling tool body is rotated, and position the superhard exterior surface to be in direct contact with the formation or formation cuttings as the drilling tool body is rotated and urged axially forward;
a source of electromagnetic radiation with wavelength in the range from 100 nm to 2600 nm configured to transmit electromagnetic radiation through the window toward the formation; and
a receiver within the drilling tool configured to receive and analyze electromagnetic radiation returning through the window, wherein the source and the receiver are both accommodated within the drilling tool and spaced from the at least one cutting or gauge protection element having the window;
wherein the receiver includes a spectrometer which separates returning radiation into a spectrum directed towards a plurality of light sensors.

2. The drilling tool of claim 1 , wherein at least one of the source or the receiver is optically coupled to the window by at least one light guide forming at least part of an optical path running through the drilling tool body and to the interior surface of the window.

3. The drilling tool of claim 2 , wherein the at least one light guide comprises a first light guide and a second light guide, wherein the first light guide forms a first optical path through the drilling tool body that carries electromagnetic radiation supplied by the source to the window, and wherein the second light guide forms a second optical path through the drilling tool body that carries returning electromagnetic radiation from the window for supply to the receiver, wherein the first optical path is separate and distinct from the second optical path.

4. The drilling tool of claim 3 , wherein the first light guide comprises optical fiber or a light pipe, and the second light guide comprises different optical fiber or a different light pipe.

5. The drilling tool of claim 1 , wherein at least one of the source or the receiver is positioned in a cavity in a portion of the drilling tool body which is axially above a cutting face of the drilling tool body, and which extends radially outwards to less than a full gauge of the drilling tool.

6. The drilling tool of claim 1 , wherein the drilling tool is a drill bit or underreamer and the drilling tool body includes a plurality of blades projecting from the drilling tool body to a full gauge of the drill bit or underreamer, followed axially by a portion that extends radially outwards to less than the full gauge, and at least one of the source or the receiver being positioned within one or more cavities within the such portion.

7. The drilling tool of claim 1 , wherein the drilling tool body comprises a drill bit body with a plurality of blades projecting from the drill bit body, and the at least one cutting or gauge protection element having the window is positioned in a pocket in one of the plurality of blades.

8. The drilling tool of claim 1 , wherein the receiver is optically coupled to the window by at least one light guide forming a complete optical path through the drilling tool from the interior surface of the window to the receiver.

9. The drilling tool of claim 8 , further comprising an internal passageway leading to the element with the window from a cavity containing at least one of the source or receiver, wherein the internal passageway comprises a continuous length running for at least 75% of a path length from the cavity to the window, wherein the at least one light guide is loose fit within the said length of the internal passageway with any width across the internal passageway being no more than five times any width across the at least one light guide, and wherein the internal passageway is configured so that the at least one light guide in the continuous length does not bend with a radius of curvature less than ten times any width of the at least one light guide.

10. The drilling tool of claim 8 , wherein the at least one light guide includes materials that do not emit fluorescence within the at least one light guide.

11. The drilling tool of claim 8 , wherein the source is arranged to transmit radiation within a first range of wavelengths shorter than a boundary value, and the receiver is configured to detect fluorescence within a second range of wavelengths longer than the boundary value.

12. The drilling tool of claim 11 , wherein the at least one light guide includes an optical fiber having a light transmitting core and a sheath, the sheath formed of material which does not emit fluorescence in the second range of wavelengths.

13. The drilling tool of claim 12 , wherein the sheath comprises a polyimide material or a metallic material.

14. The drilling tool of claim 11 , wherein the receiver is arranged to determine a magnitude of returning radiation at each of a plurality of wavelengths in the second range of wavelengths.

15. The drilling tool of claim 14 , wherein the receiver comprises wavelength filters for filtering the returning radiation.

16. The drilling tool of claim 1 , wherein the spectrometer is a microspectrometer that is arranged so that the returning radiation falls on a diffraction grating at a curved mirror, and the plurality of light sensors are formed or positioned on a semiconductor chip.

17. The drilling tool of claim 1 , wherein the spectrometer is a hermetically sealed component including a window for entry of electromagnetic radiation and pins arranged and designed to connect to a circuit board.

18. The drilling tool of claim 1 , wherein at least one of the source or the receiver includes one or more electronic components, and at least one of the source or the receiver being thermally connected to a flow path for fluid for cooling of the one or more electronic components.

19. The drilling tool of claim 18 , further comprising an active cooling mechanism arranged to transfer heat from the one or more electronic components to a drilling fluid flow path.

20. The drilling tool of claim 19 , wherein the active cooling mechanism comprises at least one Peltier cooler configured to transfer heat from the one or more electronic components to thermally conductive material in contact with the drilling fluid flow path.

21. The drilling tool of claim 1 , wherein the source includes a pulsed laser arranged to vaporize material of the formation in contact with the window to create a plasma, and the spectrometer is arranged to analyze electromagnetic radiation emitted from the plasma.

Assignees

• Schlumberger Technology Corp

Inventors

• Hird Jonathan Robert
• Johnson Ashley Bernard
• Cook John Mervyn

Classifications

• G01V3/30 Primary

  operating with electromagnetic waves · CPC title

• E21B10/26 Primary

  Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers (percussion drill bits with leading portion E21B10/40) · CPC title

• E21B10/42

  Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits (characterised by wear resisting parts E21B10/46; by conduits or nozzles for drilling fluid E21B10/60; by detachable or adjustable parts E21B10/62) · CPC title

• E21B10/567

  with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts · CPC title

• E21B47/013

  Devices specially adapted for supporting measuring instruments on drill bits · CPC title