Vibration Damping Tool for Downhole Electronics

Abstract

A shock reduction tool includes an upper interconnect module configured to electrically and mechanically orient and connect to an upper module and a lower interconnect module configured to electrically and mechanically orient and connect to a lower module. A shock absorber section is disposed between the upper interconnect module and the lower interconnect module. A wire management section is disposed between the upper interconnect module and the lower interconnect module. A plurality of wires electrically connect the upper interconnect module and the lower interconnect module and pass through the shock absorber section and the wire management section.

Description

BACKGROUND

Downhole tools are subjected to substantial forces and vibration during drilling. Sensor packages and other sensitive downhole electronics, such as those housed in measurement-while-drilling (MWD) tools, steering tools, gyros, or logging-while-drilling (LWD) tools, are particularly vulnerable to damage from vibration and shock during drilling. Electronics in downhole tools are often mounted in ways that reduce the vibration and shock that is felt by the electronics, but ultimately the vibration and shock still reduce the life cycle of the electronics and add fatigue and wear to the bottom hole assembly. Reducing shock and vibration felt by the electronics extends their life cycle, which saves valuable time and money that would be spent replacing or repairing the directional sensors and electronics. Accordingly, additional measures to minimize shock and vibration that reaches electronics are valuable.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the embodiments, reference will now be made to the following accompanying drawings:

FIG. 1 is a schematic representation of a drilling system including a downhole tool with a shock reduction tool according to the principles disclosed herein;

FIG. 2 schematically illustrates a MWD tool including a shock reduction tool according to the principles disclosed herein;

FIGS. 3A-3F are cross-sectional views of a shock reduction tool according to the principles disclosed herein;

FIG. 4 is a wire management section of a shock reduction tool according to the principles disclosed herein.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

The present disclosure relates to a shock and vibration reduction tool (hereinafter “shock reduction tool”) for downhole tools with electronic or sensitive mechanical components. The drawings and the description below disclose specific embodiments with the understanding that the embodiments are to be considered an exemplification of the principles of the invention, and are not intended to limit the invention to that illustrated and described. Further, it is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce desired results. The term “couple,” “couples,” or “coupled” as used herein is intended to mean either an indirect or a direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection; e.g., by conduction through one or more devices, or through an indirect connection; e.g., by convection or radiation. “Upper” or “uphole” means towards the surface (i.e. shallower) in a wellbore, while “lower” or “downhole” means away from the surface (i.e. deeper) in the wellbore.

Referring now to FIG. 1, a drill string 10 is suspended in a wellbore 12 and supported at the surface 14 by a drilling rig 16. The drill string 10 includes a drill pipe 18 coupled to a downhole tool assembly 20. The downhole tool assembly 20 includes multiple (e.g., twenty) drill collars 22, a measurement-while-drilling (MWD) tool assembly 1, a mud motor 24, and a drill bit 26. The drill collars 22 are connected to the drill string 10 on the uphole end of the drill collars 22, and the uphole end of the MWD tool assembly 1 is connected to the downhole end of the drill collars 22, or vice versa. The uphole end of the mud motor 24 is connected to the downhole end of MWD tool assembly 1. The downhole end of the mud motor 24 is connected to drill bit 26.

The drill bit 26 is rotated by rotary equipment on the drilling rig 16 and/or the mud motor 24 which responds to the flow of drilling fluid, or mud, which is pumped from a mud tank 28 through a central passageway of the drill pipe 18, drill collars 22, MWD tool assembly 1 and then to the mud motor 24. The pumped drilling fluid jets out of the drill bit 26 and flows back to the surface through an annular region, or annulus, between the drill string 10 and the wellbore 12. The drilling fluid carries debris away from the drill bit 26 as the drilling fluid flows back to the surface. Shakers and other filters remove the debris from the drilling fluid before the drilling fluid is recirculated downhole.

The drill collars 22 provide a means to set weight off on the drill bit 26, enabling the drill bit 26 to crush and cut the formations as the mud motor 24 rotates the drill bit 26. As drilling progresses, there is a need to monitor various downhole conditions. To accomplish this, the MWD tool assembly 1 measures and stores downhole parameters and formation characteristics for transmission to the surface using the circulating column of drilling fluid. The downhole information is transmitted to the surface via encoded pressure pulses in the circulating column of drilling fluid.

FIG. 2 schematically illustrates the inside of MWD tool assembly 1, in accordance with one embodiment. The MWD tool assembly 1 includes a collar 201 that includes a seat 230 in which an orienting sub 230 of an MWD tool 200 is disposed. Collar 201 is typically non-magnetic in order to allow measurements of the outside formation conditions to be taken by the MWD tool 200 from within the collar 201. In the prior art, MWD tools often include multiple discrete modules that are electronically connected to form the MWD tool 200. The multiple discrete modules are often connected using an interconnect module that provides electrical connectors and, optionally, a centralizer for centralizing the MWD tool 200 within the collar 201. Embodiments of the present disclosure place a shock reduction tool 210 between at least two modules: lower module 202 and upper module 220. Lower module 202 may include, for example, a pulser that produces pressure signals to transmit measurement data to the surface. Upper module 220 may include, for example, various sensors, such as directional sensors, microprocessors, and other electronic circuitry. Embodiments of the present disclosure are not limited to any particular combination of electronic modules for steering tools, MWD systems, LWD systems, or other downhole electronic systems.

Embodiments of the present disclosure provide a shock reduction tool that provides an electrical connection between at least two modules of a downhole tool, such as an MWD or LWD system. A cross-section of a shock reduction tool in accordance with one embodiment is shown in FIGS. 3A-3F, with FIG. 3A at the upper end of the shock reduction tool and FIG. 3F at the lower end of the shock reduction tool in this embodiment. FIG. 3A is an end view of a male or female electrical connector 303 that connects to upper module 220. FIG. 3F is an end view of a male or female electrical connector 304 that connects to lower module 202. The electrical connectors 303, 304 may be any electrical connectors adapted for use with the modules 202, 220. Common electrical connectors between MWD and LWD modules include MDM connectors.

FIG. 3B includes an upper interconnect module 301, which provides a sealed mechanical connection to the upper module 220. Similarly, FIG. 3E includes a lower interconnect module 302, which provides a sealed mechanical connection to the lower module 202. The interconnect modules 301, 302 are selected according to the specifications of the modules 202, 220. The interconnect modules 301, 302 are configured to be similar to commercially available interconnect modules. The electrical and mechanical components used for the commercially available interconnect modules are also commercially available.

From interconnect module 301, wires 340 extend downward from electrical connector 303 into an interconnect crossover 343. The wires 340 may terminate in a connector 341 with pins that pass through a pressure bulkhead feedthru 342. The interconnect crossover 343 provides the mechanical connection between a body 350 of the shock reduction tool and the interconnect module 301. In FIG. 3C, wires 351 extend through the body 350 and through shock absorber section 330. Embodiments of the present disclosure are not limited to any particular design for the shock absorber section 330. One example of a shock absorber that may be adapted for use with embodiments of the present disclosure is the ELIMINATOR HYDRAULIC SHOCK TOOL available from THRU TUBING RENTAL (“TTR”) (Houston, Tex.). Any shock absorber design may be adapted for use with embodiments of the present disclosure so long as it contains a passage for wires 351 or other electrical conduit to pass through.

The axial distance between electrical connectors varies with the axial extension and compression of the shock absorber section 330 as it absorbs and dampens shock and vibration during the drilling process. As a result, the wires extending through the shock reduction tool must have length to extend at least the maximum length possible from extension of the shock absorber section 330. Holding the wires in tension may lead to failure of the wires. Having extra slack in the wiring can lead to abrasion damage of the wires as the slack comes and goes with the changing axial length.

With these issues in mind, the shock reduction tool includes a wire management section 360, an embodiment of which is shown in FIG. 3D. In this embodiment, the wires 351 are contained in multiple sections of tubing 361. The sections of tubing 361 may be formed from, for example, stainless steel. The sections of tubing 361 are helically wound inside of the wire management section 360. Each section have tubing 361 may have multiple wires 351. In one embodiment, there are four sections of tubing 361, each with two wires 351 inside. The helically wound sections of tubing 361 may be nested within each other. The inside of the wire management section 360 may be pressure balanced and filled with dielectric fluid, such as oil, to lubricate and dampen the movement of the sections of tubing 361 as the helically wound portions extend and compress with the axial movement of the shock absorber section 330.

The inside of the wire management section 360 may be at the ambient downhole pressure. The tubing 361 may be sealed within the wire management section 360 during assembly, which results in the inside of the tubing 361 having a lower pressure than the ambient downhole pressure. If sealed without any pressure compensation, the strength of tubing 361 is selected to withstand the crushing forces resulting from the pressure differential between the inside of tubing 361 and ambient downhole pressure.

On the lower end of the wire management section 360, the wires 351 continue inside the tubing 361 to interconnect crossover 343. The wires 351 continue to connector 341 and pass through pressure bulkhead feedthru 342 to connect with the wiring inside interconnect module 302.

Although the embodiment in FIGS. 3A-3F is described in one orientation with FIG. 3A on the upper end and FIG. 3F on the lower end, those having ordinary skill in the art will appreciate that the shock reduction tool may be oriented in the opposite direction with the electrical connector ends reversed or with the wire management section 360 above the shock absorber section 330. Further, more than one shock absorber section 330 may be included in the shock reduction tool, and the wire management section 360 may be disposed in between those two or more shock absorber sections 330.

In FIG. 4, a wire management section 401 in accordance with another embodiment is shown. Instead of tubing, the wire management section 401 routes wires 402 through a flexible hydraulic hose 403, which may be armored. Each of the wires 402 may route through the single flexible hydraulic hose 403, or divided between multiple hydraulic hoses 403. The flexible hydraulic hose 403 may terminate at opposing ends with AN fittings 405, for example, to connect to other sections of the shock reduction tool.

Inside the wire management section 401, the flexible hydraulic hose 403 is arranged into a loose knot 410, which is a square knot in the embodiment shown in FIG. 4. As the ends of the hydraulic hose are pushed towards each other and pulled from each other with the travel of the shock absorber section, the loose knot 410 loosens and tightens within the constraints of the wire management section 401. The loosening and tightening of the loose knot 410 provides sufficient travel for the wires 402 contained therein to avoid excessive tension on the wires 402. Those having ordinary skill in the art will appreciate that other knot configurations may be used, or, alternatively, the hydraulic hose 403 may be arranged in a loop without being knotted. In one embodiment, at least a portion of the flexible hydraulic hose 403 may be coated or wrapped with a low friction and/or abrasion resistance coating, such as a shrink wrap Teflon® tube. The reduced friction allows for the loose knot 410 to loosen and tighten more freely within the wire management section 401 to avoid damage to the wires 402 contained therein.

The inside of wire management section 401 may be filled with fluid, such as oil, and exposed to ambient downhole pressure. The flexible hydraulic hose 403 may be fluidicly coupled to a pressure compensation chamber that allows for the inside of the flexible hydraulic hose 403 to balance with the ambient downhole pressure. At least some form of pressure compensation may be desirable because flexible hydraulic hose 403 generally has low resistance to collapse pressure. Pressure balancing reduces the pressure differential to a level that does not collapse the flexible hydraulic hose 403.

The embodiments disclosed herein allow for multiple modules containing electronics to be electrically connected through a shock reduction tool disposed between at least two modules. The shock reduction tool reduces the shock and vibration experienced by the electronics in the modules while allowing for the modules to be electrically connected using common electrical connectors. The reduction in shock and vibration can increase the life expectancy of the modules relative to what their life expectancy would be if directly interconnected as in the prior art MWDs, LWDs, and other downhole electrical systems.

While specific embodiments have been shown and described, modifications can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments as described are exemplary only and are not limiting. Many variations and modifications are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.

Claims

1. A shock reduction tool, comprising: an upper interconnect module configured to electrically and mechanically orient and connect to an upper module;a lower interconnect module configured to electrically and mechanically orient and connect to a lower module;a shock absorber section disposed between the upper interconnect module and the lower interconnect module;a wire management section disposed between the upper interconnect module and the lower interconnect module; anda plurality of wires electrically connecting the upper interconnect module and the lower interconnect module and passing through the shock absorber section and the wire management section.

2. The shock reduction tool of claim 1, wherein the wire management section is filled with fluid and exposed to ambient wellbore pressure.

3. The shock reduction tool of claim 2, wherein the plurality of wires are disposed in at least one section of tubing in the wire management section.

4. The shock reduction tool of claim 3, wherein the at least one section of tubing comprises a helically wound portion inside the wire management section.

5. The shock reduction tool of claim 4, wherein the plurality of wires are divided between a plurality of sections of tubing in the wire management section.

6. The shock reduction tool of claim 5, wherein the helically wound portions of the plurality of sections of tubing are in a nested arrangement.

7. The shock reduction tool of claim 2, wherein the plurality of wires are disposed in a flexible hydraulic hose inside the wire management section.

8. The shock reduction tool of claim 7, wherein the flexible hydraulic hose is tied into at least one knot inside the wire management section, and wherein the at least one knot is configured to loosen and tighten in response to axial movement of the shock absorber section.

9. The shock reduction tool of claim 8, wherein the inside of the flexible hydraulic hose is pressure compensated.

10. A measurement-while-drilling tool, comprising: an upper electronics module comprising at least one sensor;a lower electronics module;a shock reduction tool disposed between and configured to mechanically and electrically connect the upper electronics module and the lower electronics module, wherein the shock reduction tool comprises a shock absorber section and a wire management section.

11. The measurement-while-drilling tool of claim 10, wherein the wire management section is filled with fluid and exposed to ambient wellbore pressure.

12. The measurement-while-drilling tool of claim 11, wherein the plurality of wires are disposed in at least one section of tubing in the wire management section.

13. The measurement-while-drilling tool of claim 12, wherein the at least one section of tubing comprises a helically wound portion inside the wire management section.

14. The measurement-while-drilling tool of claim 13, wherein the plurality of wires are divided between a plurality of sections of tubing in the wire management section.

15. The measurement-while-drilling tool of claim 14, wherein the helically wound portions of the plurality of sections of tubing are in a nested arrangement.

16. The measurement-while-drilling tool of claim 11, wherein the plurality of wires are disposed in a flexible hydraulic hose inside the wire management section.

17. The measurement-while-drilling tool of claim 16, wherein the flexible hydraulic hose is tied into at least one knot inside the wire management section, and wherein the at least one knot is configured to loosen and tighten in response to axial movement of the shock absorber section.

18. The measurement-while-drilling tool of claim 17, wherein the inside of the flexible hydraulic hose is pressure compensated.