U.S. patent application number 10/321085 was filed with the patent office on 2004-06-17 for hydraulic circuit construction in downhole tools.
Invention is credited to McGregor, Ronald W., Michael, Robert K., Schultz, Roger L..
Application Number | 20040112593 10/321085 |
Document ID | / |
Family ID | 30443970 |
Filed Date | 2004-06-17 |
United States Patent
Application |
20040112593 |
Kind Code |
A1 |
McGregor, Ronald W. ; et
al. |
June 17, 2004 |
Hydraulic circuit construction in downhole tools
Abstract
A hydraulic circuit construction for use in downhole tools. In a
described embodiment, a fluid circuit construction includes first
and second layers. At least one fluid-operative component is
received in the first layer. A fluid passage is formed on a surface
of the second layer. The passage is in fluid communication with the
fluid-operative component. The second layer surface is sealingly
attached to a surface of the first layer, so that the first layer
surface closes off an outer side of the passage.
Inventors: |
McGregor, Ronald W.;
(Carrollton, TX) ; Schultz, Roger L.; (Aubrey,
TX) ; Michael, Robert K.; (Plano, TX) |
Correspondence
Address: |
KONNEKER & SMITH P. C.
660 NORTH CENTRAL EXPRESSWAY
SUITE 230
PLANO
TX
75074
US
|
Family ID: |
30443970 |
Appl. No.: |
10/321085 |
Filed: |
December 17, 2002 |
Current U.S.
Class: |
166/242.1 ;
166/242.3 |
Current CPC
Class: |
F15B 13/0892 20130101;
E21B 23/04 20130101; F15B 13/0896 20130101; F15B 13/0871 20130101;
F15B 13/081 20130101; F15B 13/0814 20130101 |
Class at
Publication: |
166/242.1 ;
166/242.3 |
International
Class: |
E21B 017/00 |
Claims
What is claimed is:
1. A fluid circuit construction for use in downhole tools,
comprising: a first layer having at least one fluid-operative
component installed therein; and a second layer having a fluid
passage formed thereon, the first and second layers being sealingly
attached to each other, and the fluid-operative component being in
fluid communication with the passage.
2. The fluid circuit construction according to claim 1, wherein
multiple fluid-operative components are installed in the first
layer.
3. The fluid circuit construction according to claim 2, wherein the
fluid-operative components are in fluid communication with each
other via the passage on the second layer.
4. The fluid circuit construction according to claim 1, wherein the
fluid passage is formed on an external surface of the second
layer.
5. The fluid circuit construction according to claim 1, wherein the
fluid passage extends circumferentially on the second layer.
6. The fluid circuit construction according to claim 1, wherein the
fluid passage provides fluid communication between multiple
radially separated ones of the fluid-operative components in the
first layer.
7. The fluid circuit construction according to claim 1, wherein
each of the first and second layers is generally tubular
shaped.
8. The fluid circuit construction according to claim 1, wherein
each of the first and second layers is generally planar shaped.
9. The fluid circuit construction according to claim 1, further
comprising a third layer having at least one fluid path formed
thereon, the path being in fluid communication with the
fluid-operative component.
10. The fluid circuit construction according to claim 9, wherein
the third layer is sealingly attached to the first layer.
11. The fluid circuit construction according to claim 9, wherein
the first layer is positioned between the second and third
layers.
12. The fluid circuit construction according to claim 1, wherein
the first and second layers are parts of a segment cut from a
member of a downhole tool.
13. The fluid circuit construction according to claim 12, wherein
an opening formed through at least one of the first and second
layers provides fluid communication between the first and second
layers.
14. The fluid circuit construction according to claim 12, wherein
the passage is formed on a surface of the second layer severed from
the first layer.
15. A fluid circuit construction for use in downhole tools,
comprising: a first layer having multiple fluid-operative
components received therein; and a second layer having at least one
fluid passage formed thereon, the passage being in fluid
communication with at least one of the fluid-operative components,
and a first surface of the first layer closing off a side of the
passage.
16. The fluid circuit construction according to claim 15, further
comprising a third layer having at least one fluid path formed
externally thereon, the path being in fluid communication with at
least one of the fluid-operative components, and a second surface
of the first layer closing off a side of the path.
17. The fluid circuit construction according to claim 16, wherein
the first layer is sealingly attached to each of the second and
third layers.
18. The fluid circuit construction according to claim 17, wherein
the first layer is positioned between the second and third
layers.
19. The fluid circuit construction according to claim 15, wherein
the first surface is bonded to the second layer.
20. The fluid circuit construction according to claim 15, wherein
the first surface is brazed to the second layer.
21. The fluid circuit construction according to claim 15, wherein
the first surface is welded to the second layer.
22. The fluid circuit construction according to claim 15, wherein
each of the first and second layers is generally tubular
shaped.
23. The fluid circuit construction according to claim 15, wherein
each of the first and second layers is generally planar shaped.
24. The fluid circuit construction according to claim 15, wherein
there are multiple fluid-operative components in the first layer,
and wherein the fluid-operative components are radially spaced
apart.
25. The fluid circuit construction according to claim 24, wherein
the passage is in fluid communication with each of the radially
spaced apart fluid-operative components.
26. A fluid circuit construction for use in downhole tools,
comprising: a first layer having a surface; and a second layer
having a fluid passage formed on a surface thereof, the first layer
surface and the second layer surface being sealingly attached, so
that the first layer surface closes off a side of the passage.
27. The fluid circuit construction according to claim 26, wherein
the first layer surface is bonded to the second layer surface.
28. The fluid circuit construction according to claim 26, wherein
the first layer surface is brazed to the second layer surface.
29. The fluid circuit construction according to claim 26, wherein
the first layer surface is welded to the second layer surface.
30. The fluid circuit construction according to claim 26, wherein
multiple fluid-operative components are installed in the first
layer, and wherein the passage provides fluid communication between
the fluid-operative components.
31. The fluid circuit construction according to claim 26, wherein
the fluid passage extends circumferentially on the second
layer.
32. The fluid circuit construction according to claim 26, wherein
the fluid passage is formed on the second layer without use of
holes intersecting in the second layer.
33. The fluid circuit construction according to claim 26, wherein
the fluid passage is formed on the second layer without
cross-drilling holes in the second layer.
34. The fluid circuit construction according to claim 26, wherein
the second layer is generally tubular shaped and the fluid passage
is formed externally on the second layer, and wherein the first
layer outwardly overlies the second layer.
35. The fluid circuit construction according to claim 26, wherein
the second layer is generally tubular shaped and the second layer
surface is an internal surface, and wherein the second layer
outwardly overlies the first layer.
36. The fluid circuit construction according to claim 26, wherein
the first layer further has at least one fluid-operative component
received therein, and the passage is in fluid communication with
the fluid-operative component.
37. The fluid circuit construction according to claim 26, wherein
the first and second layers are parts of a segment cut from a
member of a downhole tool.
38. The fluid circuit construction according to claim 37, wherein
an opening formed through at least one of the first and second
layers provides fluid communication between the first and second
layers.
39. The fluid circuit construction according to claim 37, wherein
the second layer surface is severed from the first layer
surface.
40. The fluid circuit construction according to claim 26, wherein
the first layer is an end cut from a generally tubular member of a
downhole tool.
41. The fluid circuit construction according to claim 40, wherein
the passage provides fluid communication between radially separated
bores formed in the member.
Description
BACKGROUND
[0001] The present invention relates generally to equipment and
methods utilized in conjunction with a subterranean well and, in an
embodiment described herein, more particularly provides a hydraulic
circuit construction for use in downhole tools.
[0002] Many downhole tools are operated or controlled by relatively
complex hydraulic circuits. These hydraulic circuits are made up of
hydraulic components, such as valves, restrictors, pumps, sensors,
etc., interconnected by passages. The passages interconnecting the
hydraulic components are typically formed by separate lines or
tubing extending between the components, or the passages are formed
through a solid body, such as a housing or mandrel to which the
components are connected.
[0003] When the passages are formed in a body of a downhole tool,
the passages are generally formed by drilling into the body, and
cross-drilling to form intersecting passages. Specialized drilling
machines must be used where the passages extend substantial
distances into the body. Often, ends of the passages used to
initiate the drilling must be closed off with plugs.
[0004] It will be appreciated that this method of constructing
hydraulic circuits in downhole tools is expensive, labor-intensive,
time-consuming and prone to error. Therefore, it would be
advantageous to provide improved hydraulic circuit construction for
use in downhole tools.
SUMMARY
[0005] In carrying out the principles of the present invention, in
accordance with an embodiment thereof, an improved fluid circuit
construction is provided which solves the above problems in the
art. This circuit construction utilizes passages formed initially
on a surface of a circuit layer to interconnect fluid-operative
components installed on another layer. Thus, extensive drilling and
cross-drilling to form the passages and interconnect the components
is eliminated, or at least substantially reduced.
[0006] In one aspect of the invention, a fluid circuit construction
for use in downhole tools is provided which includes a first layer
having at least one fluid-operative component installed therein and
a second layer having a fluid passage formed thereon. The first and
second layers are sealingly attached to each other, and the
fluid-operative component is in fluid communication with the fluid
passage.
[0007] In another aspect of the invention, a fluid circuit
construction for use in downhole tools is provided which includes a
first layer having multiple fluid-operative components received
therein and a second layer having at least one fluid passage formed
thereon. The fluid passage is in fluid communication with at least
one of the fluid-operative components. A surface of the first layer
closes off an outer side of the fluid passage on the second
layer.
[0008] In yet another aspect of the invention, a fluid circuit
construction for use in downhole tools is provided which includes a
first layer having at least one fluid-operative component received
therein and a surface, and a second layer having a fluid passage
formed on a surface thereof. The fluid passage is in fluid
communication with the fluid-operative component. The first layer
surface and the second layer surface are sealingly attached, so
that the first layer surface closes off an outer side of the fluid
passage.
[0009] These and other features, advantages, benefits and objects
of the present invention will become apparent to one of ordinary
skill in the art upon careful consideration of the detailed
description of representative embodiments of the invention
hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross-sectional view of a prior art hydraulic
circuit construction;
[0011] FIG. 2 is a cross-sectional view of the prior art hydraulic
circuit construction, taken along line 2-2 of FIG. 1;
[0012] FIG. 3 is a schematic cross-sectional view of a first fluid
circuit construction embodying principles of the present
invention;
[0013] FIG. 4 is a cross-sectional view of the first fluid circuit
construction, taken along line 4-4 of FIG. 3;
[0014] FIG. 5 is a schematic side view of a passage layer of a
second fluid circuit construction embodying principles of the
present invention;
[0015] FIG. 6 is a schematic end view of a fluid-operative
component layer of the second fluid circuit construction;
[0016] FIC. 7 is a cross-sectional view of the fluid-operative
component layer, taken along line 7-7 of FIG. 6;
[0017] FIG. 8 is a schematic isometric view of a third fluid
circuit construction embodying principles of the present
invention;
[0018] FIG. 9 is a schematic isometric exploded assembly view of a
fourth fluid circuit construction embodying principles of the
present invention;
[0019] FIGS. 10-13 are schematic views of a fifth fluid circuit
construction embodying principles of the present invention; and
[0020] FIG. 14 is a schematic isometric exploded assembly view of a
sixth fluid circuit construction embodying principles of the
present invention.
DETAILED DESCRIPTION
[0021] A prior art hydraulic circuit construction 10 is illustrated
in FIGS. 1 & 2. An element of a downhole tool, such as a
tubular mandrel 12 has a hydraulic component, such as a valve 14
installed therein. The valve 14 is installed in a hole 16, which is
then closed off by installing a plug 18 in the hole.
[0022] To provide fluid communication longitudinally through the
mandrel 12, another hole 20 is drilled in a sidewall of the
mandrel. The hole 20 is usually relatively difficult and
time-consuming to drill, due to its small diameter/length ratio and
the need for it to be accurately directed to intersect the hole 16.
Another plug 22 is used to close off an end of the hole 20.
[0023] As depicted in FIG. 2, when it is necessary to provide fluid
communication between the valve 14 and another region radially
separated relative to the mandrel 12, a series of cross-drilled
holes 24, 26 must be drilled into the mandrel sidewall. Again,
these holes 24, 26 are difficult and time-consuming to drill, since
they must accurately intersect each other in the mandrel 12
sidewall, the interior of which is not visible during the drilling
process. One or more plugs 28 are again used to close off open ends
of the holes 24, 26.
[0024] It will be readily appreciated that, even with the
relatively simple prior art hydraulic circuit construction 10
illustrated in FIGS. 1 & 2, an unduly large number of difficult
and time-consuming steps are required to form the hydraulic
circuit. This makes the prior art hydraulic circuit construction 10
very expensive to produce. The problem is compounded when it is
necessary for a hydraulic path to deviate from a straight line,
such as to extend circumferentially in the tubular mandrel 12
sidewall.
[0025] Representatively illustrated in FIGS. 3 & 4 is a fluid
or hydraulic circuit construction 30 which embodies principles of
the present invention. In the following description of the
hydraulic circuit construction 30 and other apparatus and methods
described herein, directional terms, such as "above", "below",
"upper", "lower", etc., are used only for convenience in referring
to the accompanying drawings. Additionally, it is to be understood
that the various embodiments of the present invention described
herein may be utilized in various orientations, such as inclined,
inverted, horizontal, vertical, etc., and in various
configurations, without departing from the principles of the
present invention.
[0026] The circuit construction 30 is referred to in the
description below as a "hydraulic" circuit construction as an
example of a fluid circuit construction which may benefit from the
invention. However, other types of fluid circuits which are not
specifically hydraulic circuits (such as pneumatic or other gas
circuits) may also benefit from the invention. Thus, the principles
of the invention are not limited to use in only hydraulic
circuits.
[0027] The hydraulic circuit construction 30 utilizes a layered
construction, wherein hydraulic passages or paths are formed on
surfaces of mating layers. In this manner, little or no drilling is
required to interconnect hydraulic components. The hydraulic paths
may be formed, for example, by milling the paths on the layer
surfaces. When the layers are attached to each other, one layer
surface will close off a side of a hydraulic path formed on a
surface of another layer.
[0028] In FIGS. 3 & 4, the hydraulic circuit construction 30 is
demonstrated as part of a generally tubular mandrel 32 of a
downhole tool. The mandrel 32 includes an inner layer 34, a middle
layer 36 and an outer layer 38. However, it should be understood
that the principles -of the invention are not limited to the
specific details of the hydraulic circuit construction 30 depicted
in FIGS. 3 & 4. For example, it is not necessary for the
hydraulic circuit construction 30 to be formed in a tubular member
or element, and it is not necessary for the hydraulic circuit
construction to include three layers 34, 36, 38. Any shape may be
used, and any number of layers may be used, in keeping with the
principles of the invention.
[0029] A hydraulic or fluid-operative component, such as a valve 40
is received in a sidewall of the middle layer 36. As used herein,
the term "fluid-operative component" is used to indicate an element
which regulates or otherwise controls fluid flowing therethrough,
which operates in response to a fluid property, or which senses a
property of fluid. Thus, pumps, valves, chokes, restrictors,
pistons, and pressure and temperature sensors are examples of
fluid-operative components. Fluid-operative components may be
mechanical, electronic, electrical, optical, thermal, magnetic or
other types of devices.
[0030] As depicted in FIGS. 3 & 4, the valve 40 is installed in
an end of the middle layer 36. A hole 42 drilled through the middle
layer 36 provides fluid communication with the valve 40. The hole
42 extends between outer and inner external surfaces 44, 46 of the
middle layer 36.
[0031] A fluid path or passage 48 is formed on an outer external
surface 50 of the inner layer 34. The passage 48 extends
longitudinally on the inner layer 34. The passage 48 may be fairly
easily formed on the surface 50, for example, by using a mill to
cut the passage onto the surface. Note that it is far easier to
mill a long path, such as the passage 48, onto an external surface
than it is to drill a hole of the same cross-sectional area and
length.
[0032] Another fluid path or passage 52 is formed on an inner
surface 54 of the outer layer 38. The passage 52 extends
circumferentially in the outer layer 38. The passage 52 may be
fairly easily formed on the surface 54, for example, by using a
lathe to cut the passage onto the surface. Note that it is far
easier to lathe-cut a circumferential path than it is to
cross-drill intersecting holes to form a circumferential path.
[0033] The layers 34, 36, 38 are sealingly attached to each other
to make up the mandrel 32. When the outer surface 44 of the middle
layer 36 is attached to the inner surface 54 of the outer layer 38,
the outer surface 44 closes off an inner side of the passage 52,
except for where the hole 42 provides fluid communication with the
valve 40. When the inner surface 46 of the middle layer 36 is
attached to the outer surface 50 of the inner layer 34, the inner
surface 46 closes off an outer side of the passage 48, except for
where the hole 42 provides fluid communication with the valve 40.
Thus, the valve 40 can control fluid flow between the passages 48,
52 in the hydraulic circuit construction 30.
[0034] The surfaces 44, 46, 50, 54 of the layers 34, 36, 38 may be
attached to each other using any appropriate means. For example,
the surfaces 44, 46, 50, 54 may be adhered or bonded to each other
using an epoxy, such as a thermoset epoxy. As another alternative,
the surfaces 44, 46, 50, 54 could be furnace brazed or welded to
each other.
[0035] It may now be fully appreciated that the hydraulic circuit
construction 30 illustrated in FIGS. 3 & 4 is far superior to
the prior art hydraulic circuit construction 10. These advantages
become even more apparent when more complex hydraulic circuits are
needed in downhole tools. In these situations, it becomes
infeasible, or at least extremely difficult, to drill and
cross-drill a large number of holes to form the hydraulic circuit.
However, it remains fairly easy to form complex hydraulic passages
on external surfaces, for example, by milling the passages.
[0036] Turning now to FIGS. 5-7, another hydraulic circuit
construction 60 embodying principles of the present invention is
representatively and schematically illustrated. In FIG. 5 it may be
seen that a relatively complex arrangement of fluid passages 62 has
been cut into an external surface 64 of a tubular layer 66.
[0037] The passages 62 are used to provide fluid communication
between multiple fluid-operative components 68 installed in another
tubular layer 70 of the hydraulic circuit construction 60 depicted
in FIG. 6. The components 68 are radially spaced apart in the layer
70, and so portions of the passages 62 extend circumferentially on
the layer 66. As viewed in FIG. 7, some of the components 68 may
also be longitudinally spaced apart in the layer 70, and so
portions of the passages 62 also extend longitudinally on the layer
66.
[0038] In assembly, the outer surface 64 of the layer 66 is
sealingly attached to an inner surface 72 of the layer 70. Any
method may be used for this sealing attachment, such as bonding,
welding, brazing, etc. When so attached, the inner surface 72
closes off an outer side of the passages 62.
[0039] An example of a similar hydraulic circuit construction 80
being assembled is depicted in FIG. 8. An inner tubular layer 82
having fluid passages 84 formed thereon is being inserted into a
tubular middle layer 86 having fluid-operative components 88
installed therein. Once assembled, the layers 82, 86 are sealingly
attached to each other, and the passages 84 then provide fluid
communication between the components 88, or between the components
and other portions of the downhole tool.
[0040] An outer tubular layer go may be used to externally close
off passages or holes in the middle layer 86, although use of such
an outer layer is not necessary in keeping with the principles of
the invention. It should also be understood that it is not
necessary for the components 88 to be installed in the middle layer
86, or for the passages 84 to be formed on the inner layer 82. The
components 88 could instead, or in addition, be installed in the
inner or outer layers 82, go, and the passages 84 could be formed
on the middle or outer layers 86, go.
[0041] Referring additionally now to FIG. 9, another hydraulic
circuit construction 100 embodying principles of the present
invention is representatively illustrated. Instead of a tubular
shape as depicted in FIGS. 3-8, the hydraulic circuit construction
100 has a planar shape. Thus, it may be appreciated that the
principles of the invention may be incorporated into downhole tools
in any shape of hydraulic circuit construction.
[0042] As depicted in FIG. 9, multiple fluid-operative components
102 are installed in a middle layer 104. Fluid paths or passages
106 are formed on an external surface 108 of an outer layer 110.
When the layers 104, 110 are sealingly attached to each other, the
passages 106 provide fluid communication between the components
102, and the layer 104 closes off a side of the passages 106.
[0043] The passages 106 are depicted in dashed lines on the middle
layer 104, so that it may be seen how the passages interconnect
holes 112 drilled through the middle layer. Another layer 114 may
be sealingly attached to the middle layer 104, for example, to
close off upper ends of the holes 112. Alternatively, or in
addition, the upper layer 114 may have passages, such as the
passages 106, formed thereon to provide further paths for fluid
communication between the components 102 or other portions of a
downhole tool.
[0044] Referring additionally now to FIGS. 10-13, another hydraulic
circuit construction 120 embodying principles of the invention is
representatively illustrated. In this circuit construction 120, a
generally tubular member 122 of a downhole tool has a portion or
segment 124 cut from the member. For example, the segment 124 could
be cut from the member 122 using wire EDM methods well known to
those skilled in the art.
[0045] As depicted in FIG. 10, the segment 124 has parallel lateral
surfaces 126 and a radiused inner surface 128. It should be clearly
understood, however, that the invention is not limited to any
particular shape or configuration of the member 122 or the segment
124. For example, the member 122 could be planar or otherwise
shaped. The segment 124 could be wedge-shaped, in which case the
sides 126 would not be parallel, and the inner surface 128 could be
flat, without departing from the principles of the invention.
[0046] In FIG. 11, the segment 124 has been cut into overlapping
layers 130, 132, for example, using wire EDM methods. A fluid
passage 134 has been formed on an upper surface 142 of the inner
layer 132, for example, by milling. Note that the surface 142 is
severed from the outer layer 130 when the layers 130, 132 are cut
apart. Thus, the surface 142 should precisely match an inner
surface 144 of the outer layer 130. Fluid-operative components 136
are installed in each of the layers 130, 132.
[0047] The layers 130, 132 are then reassembled with the remainder
of the member 122, as depicted in FIG. 12. The layers 130, 132 and
the remainder of the member 122 are then attached to each other,
for example, by bonding, brazing or welding. If desired, the
components 136 may be installed after the attaching step, to
prevent damage to the components from the brazing or welding
processes. The outer layer 130 now closes off an upper side of the
passage 134. At this point, the fluid-operative components 136 are
in fluid communication with each other, and/or with other portions
of the well tool, via the passage 134.
[0048] An alternate construction is shown in FIG. 13, wherein the
segment 124 is divided into four layers 138. It will be readily
appreciated that, no matter the number of layers 138, fluid
communication between the layers can be readily achieved by simply
forming an opening 140 between the layers.
[0049] Referring additionally now to FIG. 14, another hydraulic
circuit construction 150 is representatively illustrated. This
circuit construction 150 demonstrates another method whereby
circumferentially separated fluid-operative components may be
placed in fluid communication using the principles of the
invention.
[0050] Piston bores 152 are formed longitudinally in the wall of a
generally tubular member 154 of a downhole tool. For example, the
downhole tool could be a subsurface safety valve, in which case the
bores 152 could be for rod pistons (not shown) of the type well
known to those skilled in the safety valve art. The bores 152 are
radially spaced apart, for example, by 180.degree., and it is
desired to provide fluid communication between the bores.
[0051] To accomplish this result, a segment or portion 156 is cut
from an end of the member 154. As depicted in FIG. 14, the segment
156 is cut from the member 154 after the bores 152 have been formed
in the member. However, if it is desired to use the segment 156 to
close off ends of the bores 152, the segment 156 could be cut from
the member 154 prior to forming the bores.
[0052] With the segment 156 removed, a hydraulic passage 158 is
formed on an end surface 160 of the member 154. For example, the
circumferentially extending passage 158 could be milled on the
surface 160 between the bores 152. Alternatively, the passage 158
could extend in a complete circle on the surface 160, in which case
the passage could be lathe-cut on the surface.
[0053] After the passage 158 is formed, the segment 156 is attached
to the remainder of the member 154, for example, by bonding,
welding or brazing. The segment 156 then closes off an outer side
of the passage 158, so that the passage forms an enclosed fluid
communication path between the piston bores 152.
[0054] Of course, a person skilled in the art would, upon a careful
consideration of the above description of representative
embodiments of the invention, readily appreciate that many
modifications, additions, substitutions, deletions, and other
changes may be made to these specific embodiments, and such changes
are contemplated by the principles of the present invention.
Accordingly, the foregoing detailed description is to be clearly
understood as being given by way of illustration and example only,
the spirit and scope of the present invention being limited solely
by the appended claims and their equivalents.
* * * * *