Drillpipe structures to accommodate downhole testing

• US 6,710,600 B1
• Filed: 05/18/1998
• Issued: 03/23/2004
• Est. Priority Date: 08/01/1994
• Status: Expired due to Fees

• Current Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Wisler, MacMillian M., Kopecki, Denis S., John, Hendrik
• Primary Examiner(s): Snow, Walter E.
• Application Number:
  US09/080,413
• Time in Patent Office: 2,136 Days
• Field of Search: 324/338, 324/339, 324/346, 324/356, 324/369, 324/333, 175/320, 166/242.1, 138/140
• US Class Current: 324/338
• CPC Class Codes: E21B 47/01 Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like
• CPC Class Codes: G01V 3/30 operating with electromagnetic waves

Abstract

A drill collar structure to facilitate measurement-while-drilling (MWD) techniques while at the same time having sufficient rigidity to facilitate the drilling operation is disclosed. In some embodiments, a metal structure involving openings such as slots, preferably oriented longitudinally along its axis, but also in other configurations, are disclosed to allow sufficient strength while at the same time allowing exit and entrance of electromagnetic energy. A composite structure is also disclosed which, for given layers, has adjacent fibers such as glass and carbon, so that when the layers are overlapped, glass areas overlap glass areas throughout the radial thickness of the composite tube to create “windows” for the entrance and exit of electromagnetic energy. In yet other embodiments, the drill collar can be made of a metallic frame structure with a multiplicity of openings which are filled with a composite material. The metallic frame structure provides structural rigidity while the openings, filled with composite material which are attached to the metal structure, form a fluid-tight cohesive structure sufficient to withstand the rigors of drilling, while at the same time allow the measurements of the formation to be taken through the windows or by making use of sensors embedded in the windows. In another alternative composite structure, carbon fibers can be used if they are electrically insulated in the areas where electromagnetic energy is to enter and exit the structure. Another composite alternative is to alternate carbon and glass fibers in particular sequences or to use insulated carbon fibers to facilitate the operation of instruments which can be mounted in the structure whose operation could be negatively affected by conductivity in the wall in an azimuthal direction.

Claims

1. A drill pipe, comprising:

a nonmetallic wall structure having an upper and a lower end, said wall structure defining a flowpath extending from said upper to said lower end and capable of withstanding differential pressure and applied torque and comprising, at least in part, at least one component made of a material which is presented within said structure in a manner as to permit the passage of electromagnetic energy; and

said wall structure is further formed by a plurality of layers, each layer comprises discrete bands of electromagnetically transparent and non-electromagnetically transparent materials, said wall structure is created by overlapping said layers in a manner that the bands of electromagnetically transparent materials overlap each other to create at least one electromagnetically transparent window.

2. The drill pipe of claim 1, wherein:

said wall structure is made in part of a composite material.

3. The drill pipe of claim 2, wherein:

said wall structure comprises a plurality of layers wherein each layer is made in part of material that permits the passage of electromagnetic energy.

4. The drill pipe of claim 3, wherein:

each overlapping layer is oriented with respect to its adjacent layer so that components made from a material which permits passage of electromagnetic energy overlap, at least in part, in every layer in said wall.

5. The drill pipe of claim 4, wherein:

each layer comprises a plurality of carbon fibers adjacent a plurality of glass fibers.

6. The drill pipe of claim 5, wherein:

said carbon and glass fibers are in alternating bands so that glass fibers in one layer overlap glass fibers in an adjacent layer, such that at least one window of overlapping glass fibers extends through said wall.

7. The drill pipe of claim 1, wherein:

said wall further comprises instrumentation, located adjacent said component which permits passage of electromagnetic energy, said instrumentation uses electromagnetic energy to measure formation properties when the drill pipe is located downhole.

8. The drill pipe of claim 1, further comprising:

a sonde insertable into said flowpath to position instrumentation adjacent said component which permits passage of electromagnetic energy to facilitate use of said instrumentation in testing of a formation using electromagnetic energy when the drill pipe is located downhole.

9. The drill pipe of claim 6, wherein:

said wall further comprises instrumentation located adjacent said window which uses electromagnetic energy to measure formation properties when the drill pipe is located downhole.

10. The drill pipe of claim 6, further comprising:

a sonde insertable into said flowpath to position instrumentation adjacent said window to facilitate testing of a formation using electromagnetic energy when the drill pipe is located downhole.

11. A composite drill pipe to resist conductively in an azimuthal or helical direction, comprising:

a composite tubular wall structure defining a flowpath therein extending from an upper to a lower end thereof and comprising at least in past fibers which, in their position in the wall structure, are not azimuthally conductive or are less azimuthally conductive than other fibers within said wall structure said wall structure comprising sufficient strength to withstand differential pressure and torque imposed during drilling.

12. The drill pipe of claim 11, wherein:

said wall comprises of a plurality of overlapping layers and at least one of said layers comprises an alternating pattern of more-conductive and less-conductive fibers.

13. The drill pipe of claim 12, wherein:

carbon fibers are alternated with glass fibers.

14. The drill pipe of claim 13, wherein:

each carbon fiber is between a glass fiber on either side.

15. The drill pipe of claim 13, wherein:

a plurality of carbon fibers is between at least one glass fiber on either side.

16. The drill pipe of claim 11, wherein:

at least some fibers are insulated to make them less azimuthally conductive than they would be if they were not insulated.

17. The drill pipe of claim 16, wherein:

said insulated fibers comprise carbon fibers.

18. The drill pipe of claim 16, wherein:

some fibers are noninsulated carbon fibers and others are insulated carbon fibers to form azimuthal conductivity gaps.

19. The drill pipe of claim 11, further comprising:

instrumentation mounted, at least in part, in said wall for measuring while drilling with drill pipe where reduced azimuthal conductivity facilitates the measurement.

20. The drill pipe of claim 11, further comprising:

instrumentation mounted to a sonde insertable into said flowpath for measuring while drilling with drill pipe where reduced azimuthal conductivity facilitates the measurement.

21. The drill pipe of claim 13, wherein:

glass fibers overlap in every layer to create windows which allow passage of electromagnetic energy.

22. A drill pipe, comprising:

a tubular metallic structure having a flowpath from an upper to a lower end thereof defining a plurality of voids extending through said structure;

covers in said voids attached to said tubular structure to allow the assembly of said tubular metallic structure and said covers to withstand pressure differential and applied torque acting on said covers during drilling while facilitating measurements through said voids while drilling, said covers allow passage of electromagnetic energy.

25. The drill pipe of claim 22, wherein:

said covers are made of a composite material.

26. The drill pipe of claim 25, wherein:

said covers comprise fiber reinforcement.

29. The drill pipe of claim 22, wherein:

said structure further comprises metallic thread at each end for connection down to a drill string.

23. Drill pipe, comprising:

a tubular metallic structure having a flowpath from an upper to a lower end thereof defining a plurality of voids extending through said structure;

covers in said voids attached to said tubular structure to allow the assembly of said tubular metallic structure and said covers to withstand pressure differential and applied torque acting on said covers during drilling while facilitating_measurements through said voids while drilling, said covers allow passage of electromagnetic energy; and

instrumentation mounted at least in part in said covers to facilitate at least one of (1) downhole measurements of the surrounding formation outside said tubular structure, (2) measurements of fluid conditions within the tubular structure, or (3) measurement of the condition of the covers.

30. The drill pipe of claim 23, wherein:

said instrumentation performs at least one of the following measurements;

electromagnetic, gamma ray density, NMR, acoustic, resistivity, directional, pressure, fiber optic, optical distance chemical analysis (spectroscopy), borehole scope, stress measurement in said metallic structure or said covers, vibration, and other applied mechanical forces.

24. A drill pipe, comprising:

a tubular metallic structure having a flowpath from an upper to a lower end thereof defining a plurality of voids extending through said structure;

covers in said voids attached to said tubular structure to allow the assembly of said tubular metallic structure and said covers to withstand pressure differential and applied torque acting on said covers during drilling while facilitating measurements through said voids while drilling, said covers allow passage of electromagnetic energy; and

instrumentation mounted on a sonde and supported within the tubular structure so that measurements of fluid conditions within said tubular structure or of formation properties outside said tubular structure through said covers can be accomplished.

31. The drill pipe of claim 24, wherein:

said instrumentation performs at least one of the following measurements;

electromagnetic, gamma ray density, NMR, acoustic, resistivity, directional, pressure, fiber optic, optical distance chemical analysis (spectroscopy), borehole scope, stress measurement in said metallic structure or said covers, vibration, and other applied mechanical forces.

32. The drill pipe of claim 24, wherein:

said instrumentation on said sonde comprises at least one antenna;

said tubular structure comprises at least one electrically conductive loop;

wherein said antenna creates current through said loop by generating a magnetic field, which in turn allows said loop to create a magnetic field into the surrounding formation through said covers.

33. The drill pipe of claim 32, wherein:

said sonde comprises a transmitting antenna to broadcast a magnetic field into the formation using a plurality of said loops and where another antenna receives the magnetic field which returns from the formation.

27. A drill pipe, comprising:

a tubular metallic structure having a flowpath from an upper to a lower end thereof defining a plurality of voids extending through said structure;

covers in said voids attached to said tubular structure to allow the assembly of said tubular metallic structure and said covers to withstand pressure differential and applied torque acting on said covers during drilling while facilitating_measurements through said voids while drilling, said covers allow passage of electromagnetic energy;

said covers allow passage of electromagnetic energy and are made of a composite material with fiber reinforcement;

said voids are elongated and aligned with a longitudinal axis of said metallic structure.

28. A drill pipe, comprising:

a tubular metallic structure having a flowpath from an upper to a lower end thereof defining a plurality of voids extending through said structure;

covers in said voids attached to said tubular structure to allow the assembly of said tubular metallic structure and said covers to withstand pressure differential and applied torque acting on said covers during drilling while facilitating measurements through said voids while drilling, said covers allow passage of electromagnetic energy;

said covers allow passage of electromagnetic energy and are made of a composite material with fiber reinforcement;

said voids are randomly disposed in said structure.

34. A drill pipe, comprising:

a tubular metallic structure having a flowpath from an upper to a lower end thereof defining a plurality of voids extending through said structure;

covers in said voids attached to said tubular structure to allow the assembly of said tubular metallic structure and said covers to withstand pressure differential and applied torque acting on said covers during drilling while facilitating measurements through said voids while drilling, said covers allow passage of electromagnetic energy;

said covers allow passage of electromagnetic energy and are made of a composite material with fiber reinforcement;

said voids are spirally wound on said structure.