U.S. patent application number 14/198051 was filed with the patent office on 2015-09-10 for packaging for electronics in downhole assemblies.
This patent application is currently assigned to BAKER HUGHES INCORPORATED. The applicant listed for this patent is Edward Glenn Burroughs, Bernd Dreyer, Cord Huber, Robert Reinertsen, Weiqiang Wang. Invention is credited to Edward Glenn Burroughs, Bernd Dreyer, Cord Huber, Robert Reinertsen, Weiqiang Wang.
Application Number | 20150252666 14/198051 |
Document ID | / |
Family ID | 54016878 |
Filed Date | 2015-09-10 |
United States Patent
Application |
20150252666 |
Kind Code |
A1 |
Wang; Weiqiang ; et
al. |
September 10, 2015 |
PACKAGING FOR ELECTRONICS IN DOWNHOLE ASSEMBLIES
Abstract
A downhole device configured to be inserted into a borehole
includes a device body having an outer surface and a recess formed
in the outer surface and a cover covering the recess to form a
first cavity, the cover forming a fluid-tight seal with the device
body. The device includes at least one shock-absorber configured to
support an electrical module within the first cavity, the at least
one shock-absorber extending between a base of the cavity and an
inner surface of the cover opposite the base. The device also
includes a vibration-damping layer located on at least one of the
base of the cavity and the inner surface of the cover, the
vibration-damping layer configured to be in contact with a surface
of the electrical module to dampen vibration of the electrical
module.
Inventors: |
Wang; Weiqiang; (Houston,
TX) ; Reinertsen; Robert; (Spring, TX) ;
Burroughs; Edward Glenn; (Houston, TX) ; Dreyer;
Bernd; (Houston, TX) ; Huber; Cord; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Wang; Weiqiang
Reinertsen; Robert
Burroughs; Edward Glenn
Dreyer; Bernd
Huber; Cord |
Houston
Spring
Houston
Houston
Houston |
TX
TX
TX
TX
TX |
US
US
US
US
US |
|
|
Assignee: |
BAKER HUGHES INCORPORATED
Houston
TX
|
Family ID: |
54016878 |
Appl. No.: |
14/198051 |
Filed: |
March 5, 2014 |
Current U.S.
Class: |
166/66 |
Current CPC
Class: |
E21B 47/017
20200501 |
International
Class: |
E21B 47/01 20060101
E21B047/01; E21B 17/07 20060101 E21B017/07; E21B 47/00 20060101
E21B047/00 |
Claims
1. A downhole device configured to be inserted into a borehole, the
downhole device comprising: a device body having an outer surface
and a recess formed in the outer surface; a cover covering the
recess to form a first cavity, the cover forming a fluid-tight seal
with the device body; at least one shock-absorber configured to
support an electrical module within the first cavity, the at least
one shock-absorber extending between a base of the cavity and an
inner surface of the cover opposite the base; and a
vibration-damping layer located on at least one of the base of the
cavity and the inner surface of the cover, the vibration-damping
layer configured to be in contact with a surface of the electrical
module to dampen vibration of the electrical module.
2. The downhole device of claim 1, wherein the downhole device is a
segment of a downhole assembly, and the device body is a collar
body defining a second cavity extending end-to-end through the
collar body.
3. The downhole device of claim 2, wherein the second cavity is
configured to have a fluid flow therethrough, and the
vibration-damping layer is made of a temperature-transmitting
material configured to transmit heat from the electrical module,
through the vibration-damping layer and the collar body, to the
fluid.
4. The downhole device of claim 1, wherein the downhole device is a
downhole probe configured to be inserted into the borehole to
obtain measurements of characteristics of one or more of the
borehole, fluid in the borehole, and an earth formation.
5. The downhole device of claim 1, wherein the at least one
shock-absorber includes a first shock-absorber configured to
support a first end of the electrical module and a second
shock-absorber configured to support a second end of the electrical
module opposite the first end.
6. The downhole device of claim 5, wherein the vibration-damping
layer is located between the first shock-absorber and the second
shock-absorber.
7. The downhole device of claim 1, wherein the at least one
shock-absorber is configured to maintain the electrical module
stationary within the first cavity by contacting a first surface of
the electrical module facing the base of the first cavity, a second
surface of the electrical module opposite the first surface and
facing the cover.
8. The downhole device of claim 7, wherein the at least one
shock-absorber is configured to maintain the electrical module
stationary within the first cavity by contacting each surface of
the electrical module.
9. The downhole device of claim 1, wherein the at least one
shock-absorber is configured to maintain the electrical module
stationary within the first cavity without screws.
10. The downhole device of claim 1, wherein the shock-absorber is a
pre-formed elastomer.
11. The downhole device of claim 1, wherein the vibration-damping
layer is made of a viscoelastic material.
12. The downhole device of claim 1, wherein the cover is a sleeve
covering an entire outer radial surface of the device body.
13. A downhole assembly having a plurality of downhole segments for
being inserted in a borehole, the downhole assembly comprising: a
first downhole segment, among the plurality of downhole segments,
having a recess in an outer surface of a collar body defining a
first cavity and the collar body defining a second cavity extending
end-to-end through the collar body, the first downhole segment
including a cover covering the first cavity to sealingly enclose
the first cavity; at least one shock-absorber configured to support
an electrical module within the first cavity, the at least one
shock-absorber extending between a base of the first cavity and an
inner surface of the cover; and a vibration-damping layer located
on the base of the first cavity and configured to be in contact
with a surface of the electrical module to damp vibration of the
electrical module.
14. The downhole assembly of claim 13, wherein the at least one
shock-absorber includes a first shock-absorber configured to
support a first end of the electrical module and a second
shock-absorber configured to support a second end of the electrical
module opposite the first end.
15. The downhole assembly of claim 14, wherein the
vibration-damping layer is located between the first shock-absorber
and the second shock-absorber.
16. The downhole assembly of claim 13, wherein the plurality of
downhole segments include a channel configured to have fluid flow
therethrough, the second cavity being part of the channel, the
vibration-damping layer being made of a temperature-transmitting
material for transmitting heat from the electrical module, through
the vibration-damping layer and the collar body to the fluid.
17. The downhole assembly of claim 13, wherein the at least one
shock-absorber is configured to maintain the electrical module
stationary within the first cavity by contacting each surface of
the electrical module.
18. The downhole assembly of claim 13, wherein the at least one
shock-absorber is configured to maintain the electrical module
stationary within the first cavity without screws.
19. The downhole assembly of claim 13, wherein the shock-absorber
is a pre-formed elastomer.
20. The downhole assembly of claim 13, wherein the
vibration-damping layer is made of a viscoelastic material.
Description
BACKGROUND
[0001] Embodiments of the invention relate to downhole segments of
downhole assemblies for use in boreholes, and in particular to
packaging for electronics in downhole assemblies.
[0002] Electrical devices are used in all types of environments
including extremes of temperatures, vibration and shock. In
downhole environments, such as oil wells or boreholes, downhole
pipes are subjected to mechanical shock and vibration during
drilling operations or well completion operations. Electrical
circuitry in the downhole pipes may be damaged by the mechanical
shock and vibration. In addition, the electrical circuitry
generates heat, and in downhole environments where electrical
circuitry must be enclosed to protect the circuitry from fluids in
the borehole, the heat may build up without sufficient sinking,
which may damage the circuitry.
SUMMARY
[0003] Embodiments of the invention relate to a downhole device
configured to be inserted into a borehole. The device includes a
device body having an outer surface and a recess formed in the
outer surface and a cover covering the recess to form a first
cavity, the cover forming a fluid-tight seal with the device body.
The device includes at least one shock-absorber configured to
support an electrical module within the first cavity, the at least
one shock-absorber extending between a base of the cavity and an
inner surface of the cover opposite the base. The device also
includes a vibration-damping layer located on at least one of the
base of the cavity and the inner surface of the cover, the
vibration-damping layer configured to be in contact with a surface
of the electrical module to dampen vibration of the electrical
module.
[0004] Additional embodiments relate to a downhole assembly having
a plurality of downhole segments for being inserted in a borehole.
The downhole assembly includes a first downhole segment having a
collar body defining a first cavity extending end-to-end through
the collar body and a recess in an outer surface of the collar body
defines a second cavity. The first downhole segment includes a
cover covering the second cavity to sealingly enclose the second
cavity. At least one shock-absorber is configured to support an
electrical module within the second cavity, the at least one
shock-absorber extending between a base of the cavity and an inner
surface of the cover. A vibration-damping layer is located on the
base of the cavity and is configured to be in contact with a
surface of the electrical module to damp vibration of the
electrical module.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Referring now to the drawings wherein like elements are
numbered alike in the several Figures:
[0006] FIG. 1A is a cross-section of a downhole segment according
to an embodiment of the invention;
[0007] FIG. 1B is another cross-section of a downhole segment
according to an embodiment;
[0008] FIG. 2 is a cross-section of a downhole segment of a
downhole assembly according to an embodiment of the invention;
[0009] FIG. 3 is a cross-section of a downhole probe device
according to an embodiment of the invention;
[0010] FIG. 4 is a borehole system according to an embodiment of
the invention; and
[0011] FIG. 5 is a cross-section of a downhole segment according to
another embodiment.
DETAILED DESCRIPTION
[0012] Wellbore systems include electrical equipment located in
downhole segments and devices to perform various operations, such
as sensing functions, data processing functions, downhole assembly
control functions, or any other functions requiring electrical
circuitry. Downhole environments may be extreme and my subject the
electrical equipment to high temperatures, to mechanical shock and
to vibration, which may damage the electrical equipment.
Embodiments of the invention relate to shock absorbers and
vibration damping layers for supporting the electrical circuitry in
a downhole segment or device of a downhole assembly.
[0013] FIG. 1A illustrates a cross-sectional view of a downhole
device, and in particular a downhole segment 100 of a pipe string,
according to an embodiment of the invention. The downhole segment
100 includes a collar body 101 having a recess in an outside
surface of the collar body 101 defining a first cavity 102, and a
cover 104 covering the first cavity 102 to form a seal. In
embodiments of the invention, the cover 104 may have any shape and
may be connected to the collar body 101 in any suitable manner,
such that in operation while the downhole segment 100 is in a
borehole, the cover 104 remains affixed to the collar body 101.
Accordingly, the cover 104 may be permanently attached to the
collar body 101, such as by welding, or releasably attached to the
collar body 101, such as by one or more secure latches, screws, or
bolts. Embodiments of the invention are not limited to any type of
securing mechanism, so long as the cover 104 remains affixed to the
collar body 101 in operation while the collar body 101 is in a
downhole environment, such as a drilling operation in a
borehole.
[0014] The cover 104 may have any shape, including a shape having a
curved outer surface, as illustrated in FIG. 1, to correspond to
the shape of the outer surface of the collar body 101, or the cover
104 may have an outer surface with a substantially flat shape, or
any other desired shape. The cover 104 and collar body 101 may form
a seal to prevent fluids from flowing into the cavity 102. The seal
may be formed by welding the cover 104 to the collar body, by
inserting sealing components, such as viscoelastic materials or
rubber, between the collar body 101 and the cover 104, or by any
other means.
[0015] In embodiments of the invention, the first cavity 102 is
configured to accommodate an electrical module 105 within the
cavity 102. The electrical module 105 may be any type of device,
including sensor equipment or other processing circuitry, such as
wiring on a printed wiring board, and one or more processors,
memory chips, and other logic circuitry mounted to the printing
wiring board. In one embodiment, the electrical module 105 includes
electrical circuitry enclosed within a metal box for protecting the
circuitry and transmitting heat from the circuitry to the
surrounding environment. In addition, embodiments encompass any
type of box from protecting circuitry including plastics, ceramics,
or any other appropriate material selected according to design
considerations.
[0016] The electrical module 105 is held in place in the cavity 102
by shock absorbers 106a and 106b. In one embodiment, the
shock-absorbers 106a and 106b are made of an elastomer material.
However, embodiments encompass any material capable of absorbing
shock and supporting the electrical module 105. In one embodiment,
the shock-absorbers 106a and 106b are made of a pre-formed
elastomer, or an elastomer that has a predetermined shape prior to
being placed in the cavity 102, and maintains its shape in the
cavity 102, subject only to small amounts of compression and
expansion due to mechanical shock and vibration and compression of
the cavity 102.
[0017] In one embodiment, the shock-absorbers 106a and 106b are
shaped to maintain the electrical module 105 spaced apart from the
base 109 of the cavity 102 and from the surface 108 of the cover
104 defining an inside surface of the cavity 102. In other words,
the shock-absorbers 106a and 106b are configured to have portions
located between the surface of the electrical module 105 facing the
cover 104 and portions located between the surface of the
electrical module 105 and the base 109 of the cavity. In an
embodiment of the invention, the shock-absorbers 106a and 106b
extend from the base 109 of the cavity 102 to the inside surface
108 of the cover 104.
[0018] As illustrated in FIG. 1A, a first shock-absorber 106a
supports a first end of the electrical module 105 and a second
shock-absorber 106b supports a second end of the electrical module
105 opposite the first end. In one embodiment, the combination of
the two shock-absorbers 106a and 106b together contact each surface
of the electrical module 105, including a surface facing the cover
104, a surface facing the base 109 of the cavity 102, end surfaces
of the electrical module 105 in a width direction (illustrated as
direction X in FIG. 1A) and end surfaces of the electrical module
105 in a lengthwise direction (illustrated as direction Z in FIG.
1A). Accordingly, the shock-absorbers 106a and 106b contact each
surface of the electrical module 105 to prevent movement of the
electrical module within the cavity 102 and to maintain the
electrical module 105 suspended within the cavity 102.
[0019] Since the shock-absorbers 106a and 106b have a shape that
maintains the electrical module 105 in position in the cavity 102,
screws or other attachment devices are not necessary to fix the
electrical module 105 with respect to the collar body 101. In one
embodiment, the downhole segment 100 includes no screws or other
attachment mechanisms that attach to, or through, the electrical
module 105 to attach the electrical module 105 to the collar body
101. In other words, in one embodiment, the shock-absorbers 106a
and 106b maintain the electrical module 105 in position within the
cavity 102 without the use of screws, bolts, clamps, latches, pins,
or any other connection devices to connect the shock-absorbers 106a
and 106b to the electrical module 105, to connect the
shock-absorbers 106a and 106b to the collar body 101 or the cover
104, or to connect the electrical module 105 to the collar body 101
or cover 104.
[0020] The downhole segment 100 further includes a
vibration-damping layer 107 located on the base 109 of the cavity
102 and configured to be in contact with a surface of the
electrical module 105 to damp vibration of the electrical module
105. In one embodiment, the vibration-damping layer 107 is located
between the first shock absorber 106a and the second shock absorber
106b.
[0021] The downhole segment 100 includes a second cavity 103
extending through the collar body 101 from one end of the collar
body 101 to an opposite end. In one embodiment, the downhole
segment 100 is configured to have fluid, such as borehole fluid,
drilling mud, or any other fluid, flow through the second cavity
103. In one embodiment, the vibration-damping layer 107 is a
thermal-transmitting material for transmitting heat from the
electrical module 105 to the collar body 101, and from the collar
body 101 to the fluid in the second cavity 103.
[0022] In one embodiment, the vibration-damping layer 107 is made
of a viscoelastic material. The viscoelastic material may be a
pre-formed material, such as a pad, or the viscoelastic material
may be a paste or other material that is deposited in the cavity
102. Then the electrical module 105 may be placed on the
viscoelastic material, and the viscoelastic material may harden
into the vibration-damping layer 107.
[0023] FIG. 1A illustrates a cross-section of the downhole segment
100 along a plane perpendicular to a length axis Z of the downhole
segment 100. In other words, in an embodiment in which the downhole
segment 100 is formed as a cylinder, the length axis Z corresponds
to the axis through the cavity 103 at the center of the cylinder.
For purposes of description, the axis Y is referred to as the
height direction of the downhole segment 100, the axis X is
referred to as a width direction of the downhole segment 100, and
the axis Z is referred to as the length direction of the downhole
segment 100.
[0024] FIG. 1B is a side cross-sectional view taken along the line
I-F of FIG. 1A to illustrate a length of the downhole segment 100,
or at least a portion of the length of the downhole segment 100. As
illustrated in FIG. 1B, the downhole segment 100 includes third and
fourth shock-absorbers 112a and 112b located at the length ends of
the electrical module 105. While four shock-absorbers 106a, 106b,
112a, and 112b are illustrated in FIGS. 1A and 1B, embodiments of
the invention encompass any number of shock-absorbers, including
one shock-absorber having a shape sufficient to support the entire
electrical module 105 by running along the top or one or more sides
of the electrical module (such as in a rectangular frame shape),
two, three, or five or more shock-absorbers. In one embodiment,
only two shock-absorbers are used, located at the width ends of the
electrical module 105, as illustrated in FIG. 1A, or located at the
length ends of the electrical module 105, as illustrated in FIG.
1B.
[0025] The shock absorbers 112a and 112b include channels 115a and
115b aligned with a channel 116 in the collar body 105 to allow a
wire to be connected to the electrical module 105 and to extend
through the downhole segment 100 to another downhole segment or
other equipment.
[0026] In the embodiment illustrated in FIGS. 1A and 1B, the
electrical module 105 has a length greater than its width, its
length extends along the length direction Z of the downhole segment
100 and its width extends in the width direction X of the downhole
segment 100. However, embodiments of the invention are not limited
to the configuration illustrated in FIGS. 1A and 1B. Instead,
embodiments encompass any arrangement of the electrical module 105
relative to the collar body 101, including having a length
extending in the width direction X of the downhole segment 100,
having a length extending in the height direction Y of the downhole
segment 100, having a same width and height, having an irregular or
non-geometric shape, being arranged to be non-co-axial with any of
the width direction X, height direction Y, and length direction Z,
or having any other arrangement.
[0027] While FIGS. 1A and 1B illustrate four shock absorbers 106a,
106b, 112a and 112b, and only one vibration-damping layer 107,
embodiments of the invention encompass any number of shock
absorbers and vibration-damping layers. FIG. 2 illustrates an
embodiment of the invention similar to FIG. 1A, but further
including a second vibration-damping layer 117 between the
electrical module 105 and the inside surface 108 of the cover
104.
[0028] FIG. 3 illustrates a downhole device according to another
embodiment of the invention. In FIG. 3, the downhole device is a
probe 310 that is configured to obtain measurements in the borehole
321 formed in an earth formation 320. The probe 310 includes a
housing 311 suspended by a cable 312. Alternatively, the probe 310
may be connected to a downhole pipe or other structure to push the
probe 310 into the wellbore 321 and support the probe 310 within
the wellbore 321. A recess 313 is formed in an end surface of the
housing 311 to form a cavity 313 when a cover 314 is attached to an
end of the housing 311. The cover 314 forms a fluid-tight seal with
the housing 311 to prevent fluids from flowing into or out from the
cavity 313.
[0029] An electrical module 315 is located in the cavity 313 and
may correspond to the electrical module 105 described in connection
with FIG. 1A. The electrical module 315 may include one or more
measurement devices, such as antenna or other transmitters or
receivers, and one or more processing circuits to process signals
generated by measurement devices, to process signals generated by
uphole computers to control or monitor operation of the probe 310,
or to process any other signals generated in connection with
operation of the probe 310. The probe 310 includes shock-absorbers
316a and 316b and vibration-damping layers 317 and 317. The
shock-absorbers may correspond to the shock-absorbers 106a and 106b
described in connection with FIGS. 1A and 1B, and the
vibration-damping layers may correspond to the vibration-damping
layers 107 and 117 described in connection with FIGS. 1A, 1B, and
2.
[0030] While downhole segments, such as pipe segments, and probes
have been illustrated to provide examples of embodiments of the
invention, embodiments are not limited to the disclosed examples.
Instead, embodiments of the invention may be implemented in
connection with any type of apparatus or device that is configured
to be inserted into a borehole in an earth formation.
[0031] In addition, while FIGS. 1A, 1B, and 2 illustrate a cover
located on a side surface (or a surface located radially outward
from the center of the downhole segment), and FIG. 3 illustrates a
cover located at one end of a downhole device (i.e. a surface
located along an axial length of the device), embodiments encompass
covers located on any surface, or multiple surfaces, of a downhole
device, including either end and any side surface.
[0032] FIG. 4 illustrates a borehole system 400 according to an
embodiment of the invention. The system 400 includes a downhole
assembly 410 connected to an above-ground computer 420, which may
perform one or more of monitoring and control of the downhole
assembly 410. The downhole assembly 410 includes a derrick 411 and
motor 412 above ground, and a downhole portion 430 including one or
more downhole segments 432 in a borehole 441 of an earth formation
440. In FIG. 4, the downhole segment 432a represents the downhole
segment 100 of FIGS. 1A and 1B, including the cavity 102,
electrical module 105, shock-absorbers 106a, 106b, 112a, and 112b,
and vibration-damping layer 107. The electrical module 105 of the
downhole segment 432a communicates with the computer 420 via a wire
433 that extends through the downhole segments 432. The wire 433
may be any type of wire, including copper or other conductive metal
or fiber optic wire. In addition, embodiments of the invention
encompass any type of communication between the computer 420 and
the electrical module 105, including mud pulse telemetry,
electromagnetic telemetry, or any other type of communication.
[0033] In embodiments of the invention, the shock absorbers and
vibration-damping layer protect the electrical module during
operation of the downhole assembly 410, such as during a drilling
operation or well completion operation. Since the electrical module
is securely fit in the shock-absorbers, screws or other fixing
mechanisms are not needed to mechanically fix the electrical module
to the collar body of the downhole segment. As a result, when the
electrical module is subject to mechanical shock and vibration, the
electrical module is not subjected to stress and certain points
where screws or other fixing devices are fixed with respect to the
collar body.
[0034] In addition, the shock absorbers may be unattached to the
collar body (i.e. no adhesive, screws, or other fixing means may be
used), and instead, the shock-absorbers may fit snugly within the
space of the cavity in the collar body. As a result, if an operator
needs to access the electrical module, the cover may be removed
from the cavity and the electrical module and shock absorbers may
be removed without the need to unscrew, un-attach, or break any
fixing mechanisms.
[0035] In one embodiment of the invention, the shock absorbers are
pre-formed material having a shape designed to correspond to the
shape of an electrical module to be supported by the shock
absorbers. The shock absorbers are designed to have a shape such
that when the electrical module is positioned in the shock
absorbers to be supported by the shock absorbers, the shock
absorbers contact the inside surfaces of a cavity in a collar body
to prevent movement of the electrical module with respect to the
collar body. For example, if two shock absorbers are used to
support length ends of the electrical module, the height of the
shock absorbers is the height of the cavity with the cover
attached, a width of the shock absorbers is the width of the
cavity, and portions of the shock absorbers are located between the
ends of the electrical modules and walls of the cavity, such that
the length of the electrical module and the portions of the shock
absorbers located between the ends of the electrical modules and
walls of the cavity have the same length as the length of the
cavity. Accordingly, no screws or other attaching mechanisms are
needed to keep the electrical module in place within the cavity, so
that no stress points are generated on the electrical module and
insertion and removal of the electrical module and shock absorbers
is facilitated or made easier than when any fixing or attaching
mechanisms are used.
[0036] While embodiments have been provided in which a cover covers
a portion of a collar body having a recess, embodiments encompass
covers of any shape relative to the collar body. For example, FIG.
5 illustrates a cross-sectional view of a downhole device, and in
particular a downhole segment 500 of a pipe string, according to an
embodiment of the invention. The downhole segment 500 includes a
collar body 501 having a recess in an outside surface of the collar
body 501 defining a first cavity 502, and a cover 504, which in the
embodiment illustrated in FIG. 5 is a sleeve, covering the entire
outer radial surface of the collar body 501 including the first
cavity 502 to form a seal.
[0037] In embodiments of the invention, the first cavity 502 is
configured to accommodate an electrical module 505 within the
cavity 502. The electrical module 505 may be any type of device,
including sensor equipment or other processing circuitry, such as
wiring on a printed wiring board, and one or more processors,
memory chips, and other logic circuitry mounted to the printing
wiring board. In one embodiment, the electrical module 505 includes
electrical circuitry enclosed within a metal box for protecting the
circuitry and transmitting heat from the circuitry to the
surrounding environment. In addition, embodiments encompass any
type of box from protecting circuitry including plastics, ceramics,
or any other appropriate material selected according to design
considerations.
[0038] The electrical module 505 is held in place in the cavity 502
by shock absorbers 506a and 506b. In one embodiment, the
shock-absorbers 506a and 506b are made of an elastomer material.
However, embodiments encompass any material capable of absorbing
shock and supporting the electrical module 505. In one embodiment,
the shock-absorbers 506a and 506b are made of a pre-formed
elastomer, or an elastomer that has a predetermined shape prior to
being placed in the cavity 502, and maintains its shape in the
cavity 502, subject only to small amounts of compression and
expansion due to mechanical shock and vibration and compression of
the cavity 502.
[0039] In one embodiment, the shock-absorbers 506a and 506b are
shaped to maintain the electrical module 505 spaced apart from the
base 509 of the cavity 502 and from the surface 508 of the cover
504 defining an inside surface of the cavity 502. In other words,
the shock-absorbers 506a and 506b are configured to have portions
located between the surface of the electrical module 505 facing the
cover 504 and portions located between the surface of the
electrical module 505 and the base 509 of the cavity. In an
embodiment of the invention, the shock-absorbers 506a and 506b
extend from the base 509 of the cavity 502 to the inside surface
508 of the cover 504.
[0040] The downhole segment 500 further includes a
vibration-damping layer 507 located on the base of the cavity 502
and configured to be in contact with a surface of the electrical
module 505 to damp vibration of the electrical module 505. In one
embodiment, the vibration-damping layer 507 is located between the
first shock absorber 506a and the second shock absorber 506b.
Another vibration-damping layer 517 is located between the
electrical module 505 and the cover 504.
[0041] The downhole segment 500 includes a second cavity 503
extending through the collar body 501 from one end of the collar
body 501 to an opposite end. In one embodiment, the downhole
segment 500 is configured to have fluid, such as borehole fluid,
drilling mud, or any other fluid, flow through the second cavity
503. In one embodiment, the vibration-damping layer 507 is a
thermal-transmitting material for transmitting heat from the
electrical module 505 to the collar body 501, and from the collar
body 501 to the fluid in the second cavity 503.
[0042] In one embodiment, the vibration-damping layer 507 is made
of a viscoelastic material. The viscoelastic material may be a
pre-formed material, such as a pad, or the viscoelastic material
may be a paste or other material that is deposited in the cavity
502. Then the electrical module 505 may be placed on the
viscoelastic material, and the viscoelastic material may harden
into the vibration-damping layer 107.
[0043] While one or more embodiments have been shown and described,
modifications and substitutions may be made thereto without
departing from the spirit and scope of the invention. Accordingly,
it is to be understood that the present invention has been
described by way of illustrations and not limitation.
* * * * *