U.S. patent application number 15/754266 was filed with the patent office on 2018-08-23 for high-tensile, thin-wall differential threaded coupling.
The applicant listed for this patent is Halliburton Energy Services, Inc.. Invention is credited to Benjamin Thomas DERRYBERRY, Robert Brice PATTERSON, Paul David RINGGENBERG.
Application Number | 20180238120 15/754266 |
Document ID | / |
Family ID | 59057148 |
Filed Date | 2018-08-23 |
United States Patent
Application |
20180238120 |
Kind Code |
A1 |
PATTERSON; Robert Brice ; et
al. |
August 23, 2018 |
HIGH-TENSILE, THIN-WALL DIFFERENTIAL THREADED COUPLING
Abstract
The disclosed embodiments include a differential coupling
system, a method of coupling a first mandrel to a second mandrel
and a coupler. In one embodiment, the system includes a first
mandrel having a first external thread about an external surface of
the first mandrel. The system also includes a second mandrel having
a second external thread about an external surface of the second
mandrel. The system further includes a coupler that includes a
first internal thread that complements the first external thread of
the first mandrel and a second internal thread that complements the
second external thread of the second mandrel. The system further
includes an aligning pin configured to engage a first aligning hole
of the first mandrel and a second aligning hole of the second
mandrel to restrict axial rotation between the first mandrel and
the second mandrel when the first mandrel is engaged to the second
mandrel.
Inventors: |
PATTERSON; Robert Brice;
(Fort Worth, TX) ; DERRYBERRY; Benjamin Thomas;
(Plano, TX) ; RINGGENBERG; Paul David; (Frisco,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Halliburton Energy Services, Inc. |
Houston |
TX |
US |
|
|
Family ID: |
59057148 |
Appl. No.: |
15/754266 |
Filed: |
December 15, 2015 |
PCT Filed: |
December 15, 2015 |
PCT NO: |
PCT/US2015/065866 |
371 Date: |
February 21, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 17/042 20130101;
E21B 17/043 20130101; F16L 15/08 20130101; E21B 17/046 20130101;
F16L 2201/10 20130101; E21B 17/0426 20130101 |
International
Class: |
E21B 17/043 20060101
E21B017/043; E21B 17/042 20060101 E21B017/042; E21B 17/046 20060101
E21B017/046 |
Claims
1. A differential threaded coupling system comprising: a first
mandrel having a first external thread about an external surface of
the first mandrel; a second mandrel having a second external thread
about an external surface of the second mandrel; a coupler
comprising a first internal thread that complements the first
external thread of the first mandrel and a second internal thread
that complements the second external thread of the second mandrel;
and an aligning pin configured to engage a first aligning hole of
the first mandrel and a second aligning hole of the second mandrel
to restrict axial rotation between the first mandrel and the second
mandrel when the first mandrel is engaged to the second
mandrel.
2. The system of claim 1, wherein each tooth of the first external
thread and second external thread has a reverse lead flank angle of
approximately -3 to -30 degrees and a trailing flank angle of
approximately 30 to 60 degrees.
3. The system of claim 2, wherein the reverse lead angle is
approximately -7 degrees and the trailing flank angle is
approximately 45 degrees.
4. The system of claim 1, wherein the first external thread and
first internal thread have a first thread pitch and the second
internal thread and second external thread have a second thread
pitch, the second thread pitch being less than the first thread
pitch, such that rotation of the coupler results in an engagement
rate of the coupler to the second mandrel that is greater than a
disengagement rate of the coupler to the first mandrel.
5. The system of claim 1, wherein the coupler comprises a window
for viewing the first mandrel and second mandrel when the first and
second mandrels are coupled to the coupler.
6. The system of claim 1, further comprising a plurality of port
interfaces, each port interface forming a coupling between a first
conduit of the first mandrel and a second conduit of the second
mandrel.
7. The system of claim of claim 6, wherein the plurality of port
interfaces comprises an electrical connector, and wherein the
electrical connector is coupled to a first conduit comprising an
electrical conduit, and a second conduit comprising an electrical
conduit.
8. The system of claim of claim 6, wherein the plurality of port
interfaces comprises a hydraulic connector, and wherein the
hydraulic connector is coupled to a first conduit comprising a
fluid conduit, and a second conduit comprising a fluid conduit.
9. A method of coupling a first mandrel to a second mandrel, the
method comprising: aligning a first end of a first mandrel to a
second end of a second mandrel, the first mandrel having a first
external thread about an external surface of the first mandrel and
the second mandrel having a second external thread about an
external surface of the second mandrel; threading a coupler to the
first mandrel to engage a first internal thread of the coupler to
the first external thread of the first mandrel, wherein the first
internal thread and first external thread have a first thread
pitch; and threading the coupler to the second mandrel to engage a
second internal thread of the coupler to the second external thread
of the second mandrel, wherein the second internal thread and
second external thread have a second thread pitch, wherein the
second thread pitch is less than the first thread pitch, such that
rotating the coupler relative to the first mandrel and second
mandrel simultaneously results in the coupler engaging the second
mandrel at a faster rate than the coupler disengages the first
mandrel, and the second mandrel being drawn towards the first
mandrel until the first end of the first mandrel engages the second
end of the second mandrel.
10. The method of claim 9, wherein aligning the first end of the
first mandrel to the second end of the second mandrel comprises
aligning an aligning pin with a first aligning hole of the first
mandrel and a second aligning hole of the second mandrel, wherein
the aligning pin is configured to restrict axial rotation between
the first mandrel and the second mandrel when the first mandrel is
engaged to the second mandrel.
11. The method of claim 9, wherein aligning the first end of the
first mandrel to the second end of the second mandrel comprises
aligning a plurality of port interfaces, the method further
comprising coupling a first conduit of the first mandrel to a
second conduit of the second mandrel at each of the plurality of
port interfaces.
12. The method of claim 11, wherein the plurality of port
interfaces comprises an electrical connector, and wherein each
electrical connector is coupled to a first conduit comprising an
electrical conduit, and a second conduit comprising an electrical
conduit.
13. The method of claim 11, wherein the plurality of port
interfaces comprises a hydraulic connector, and wherein each
hydraulic connector is coupled to a first conduit comprising a
fluid conduit, and a second conduit comprising a fluid conduit.
14. The method of claim 9, further comprising aligning a first
visual indicator of the first mandrel to a second visual indicator
of the second mandrel to align the first end of the first mandrel
to the second end of the second mandrel.
15. The method of claim 14, further comprising visually determining
if the first end of the first mandrel is aligned with the second
end of the second mandrel by observing the first mandrel and second
mandrel through a window of the coupler.
16. The method of claim 9, wherein each of the first external
thread and second external thread has a reverse lead flank angle of
approximately -3 to -30 degrees and a trailing flank angle of
approximately 30 to 60 degrees.
17. The method of claim 16, wherein the reverse lead angle is
approximately -7 degrees and the trailing flank angle is
approximately 45 degrees.
18. A coupler comprising: a cavity having a first end for receiving
a first mandrel and a second end for receiving a second mandrel; a
first internal thread at the first end, the first internal thread
having a thread profile that complements a first external thread of
the first mandrel, wherein the first internal thread and first
external thread have a first thread pitch; and a second internal
thread having a thread profile that complements a second external
thread of the second mandrel, wherein the second internal thread
and second external thread have a second thread pitch, the second
thread pitch being less than the first thread pitch such that
rotating the coupler relative to the first mandrel and second
mandrel simultaneously results in the coupler engaging the second
mandrel at a faster rate than the coupler disengages the first
mandrel.
19. The coupler of claim 18, further comprising a window to provide
a view of the first mandrel and second mandrel when the first
mandrel and second mandrel are engaged by the coupler.
20. The coupler of claim 18, further comprising at least one visual
indicator indicative of a rotational position of the coupler with
respect to at least one of the first mandrel and the second
mandrel.
Description
BACKGROUND
[0001] The present disclosure relates to oil and gas exploration
and production, and more particularly to a coupling subassembly for
joining together tubing segments in a tool string.
[0002] Wells are drilled at various depths to access and produce
oil, gas, minerals, and other naturally-occurring deposits from
subterranean geological formations. Wells are also drilled in a
variety of environments, including in deep water where ocean floor
conditions may be softer or more unconsolidated. In such wells,
drill strings and completion strings may extend to a variety of
depths and may follow relatively circuitous paths to reach a
location of a geological formation that is rich in extractable
hydrocarbons.
[0003] To deploy tools at various locations and depths in the
wellbore, a tool string, which may include a running tool, may be
used to deploy tools or other devices. To form the tool string,
tubing segments may be coupled together or with tooling
subassemblies. These couplings may be achieved using coupling
subassemblies that form robust, sealed joints between segments of
tubing in a tool string. The coupling subassemblies also allow
coupled tubing segments to disengage from each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] The following figures are included to illustrate certain
aspects of the present disclosure, and should not be viewed as
exclusive embodiments. The subject matter disclosed is capable of
considerable modifications, alterations, combinations, and
equivalents in form and function, without departing from the scope
of this disclosure.
[0005] FIG. 1A illustrates a schematic view of an off-shore well in
which a tool string is deployed according to an illustrative
embodiment;
[0006] FIG. 1B illustrates a schematic view of an on-shore well in
which a tool string is deployed according to an illustrative
embodiment;
[0007] FIG. 2 illustrates a schematic, cross-section view of a
coupling assembly for joining two segments of tubing together, in
accordance with an illustrative embodiment;
[0008] FIG. 3 illustrates a perspective view of a portion of an
embodiment of a coupling used in the coupling assembly of FIG.
2;
[0009] FIG. 4A illustrates a perspective view of a portion of an
embodiment of a first mandrel used in the coupling assembly of FIG.
2;
[0010] FIG. 4B illustrates a perspective view of a portion of an
embodiment of a second mandrel used in the coupling assembly of
FIG. 2;
[0011] FIG. 5A illustrates a cross-section view of a portion of a
first external thread of the first mandrel of FIG. 4A engaged to a
first internal thread of the coupler of FIG. 3;
[0012] FIG. 5B illustrates a cross-section view of a portion of a
second external thread of the second mandrel of FIG. 4B engaged to
a second internal thread of the coupler of FIG. 3; and
[0013] FIG. 6 illustrates a perspective view of the coupling
assembly of FIG. 2 that includes the coupler of FIG. 3, the first
mandrel of FIG. 4A, and the second mandrel of FIG. 4B.
[0014] The illustrated figures are only exemplary and are not
intended to assert or imply any limitation with regard to the
environment, architecture, design, or process in which different
embodiments may be implemented.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0015] In the following detailed description of the illustrative
embodiments, reference is made to the accompanying drawings that
form a part hereof These embodiments are described in sufficient
detail to enable those skilled in the art to practice the
invention, and it is understood that other embodiments may be
utilized and that logical structural, mechanical, electrical, and
chemical changes may be made without departing from the spirit or
scope of the invention. To avoid detail not necessary to enable
those skilled in the art to practice the embodiments described
herein, the description may omit certain information known to those
skilled in the art. The following detailed description is,
therefore, not to be taken in a limiting sense, and the scope of
the illustrative embodiments is defined only by the appended
claims.
[0016] Liner hanger systems and other types of tool strings may be
used during well construction or well remediation and repair in
locations ranging from just below the wellhead system to locations
deep within a well. Tool strings used in such systems may therefore
be extendable, and may include couplings that are tolerant of
bending and vibration induced forces to resist decoupling within
the wellbore. In particular, tool strings, such as Drill String
Testing (DST) strings, that deploy running tools used to place or
set downhole equipment, such as liner hangers, plugs or packers,
may be resistant to such induced forces to maintain the integrity
of the tool string and prevent the loss of the tool in the well.
Tool strings that deploy other types of tools may be similarly
resistant to such induced forces.
[0017] Some tool strings may include coupling assemblies where
tubing segments are joined together by couplers to extend the tool
string further into a formation. The present disclosure relates to
a coupling assembly that tolerates the static and dynamic loads
experienced by the tool string and prevents the tool string from
decoupling due to hoop stress, vibration, torsion, and other forces
that may be experienced when the tool string is rotated and/or
manipulated in a well. The coupling assembly is also operable to
withstand additional loads, which may result from non-conventional
or unanticipated loading of threaded interfaces when the assembly
is navigating a tight radius in the well. In some embodiments, the
coupling assembly is used in a Landing String of a (DST string. In
one of such embodiments, the coupling assembly is installed on an
ocean floor subsea equipment such as a blowout preventer (BOP) to
provide for disconnection and isolation of tubing pressure in case
of a required ocean floor disconnect during the DST operations. In
another one of such embodiments, the coupling assembly is installed
on DST tools positioned further downhole from the ocean floor. In
further embodiments, the coupling assembly is used to couple tubing
segments in any suitable tool string, including, for example, a
running tool for deploying a liner hanger.
[0018] Turning now to the figures, FIG. 1A illustrates a schematic
view of an offshore platform 142 operating a tool string 128 that
includes a coupling assembly 100 according to an illustrative
embodiment. The coupling assembly 100 in FIG. 1A may be deployed to
couple sections of a subsea test tree residing in a blowout
preventer 139 or to couple segments of the tool string 128 in a
sub-sea well 138 accessed by the offshore platform 142. As defined
herein, the "offshore platform" 142 may be a floating platform, a
platform anchored to a seabed 140 or a vessel.
[0019] Alternatively, FIG. 1B illustrates a schematic view of a rig
104 in which a tool string 128 is deployed that includes a coupling
assembly 100 in accordance with an illustrative embodiment. The rig
104 is positioned at a surface 124 of a well 102. The well 102
includes a wellbore 130 that extends from the surface 124 of the
well 102 to a subterranean substrate or formation 134. The well 102
and the rig 104 are illustrated onshore in FIG. 1B.
[0020] FIGS. 1A-1B each illustrate possible uses or deployments of
the coupling assembly 100, which in either instance may be used in
tool string 128 to deploy a tool 144 or other device downhole. In
the embodiments illustrated in FIG. 1A and 1B, the wellbore 130 has
been formed by a drilling process in which dirt, rock and other
subterranean material has been cut from the formation 134 by a
drill bit operated via a drill string to create the wellbore 130.
During or after the drilling process, a portion of the wellbore may
be cased with a casing (not illustrated in FIGS. 1A and 1B). In
other embodiments, the wellbore may be maintained in an open-hole
configuration without casing.
[0021] The tool string 128 may include sections of tubing, each of
which are joined to adjacent tubing by threaded or other connection
types, such as coupling assembly 100. The tool string 128 may refer
to the collection of pipes, mandrels or tubes as a single
component, or alternatively to the individual pipes, mandrels, or
tubes that comprise the string. The term tool string is not meant
to be limiting in nature and may include a running tool or any
other type of tool string used to deploy the tool 144 or equipment
in the wellbore. In some embodiments, the tool string 128 may
include a passage disposed longitudinally in the tool string 128
that is capable of allowing fluid communication between the surface
124 of the well 102 and a downhole location 136. It is noted that
the coupling assembly 100 described herein may be used to couple
tubing segments in any suitable tool string, including, for
example, a running tool for deploying a liner hanger.
[0022] The lowering of the tool string 128 may be accomplished by a
lift assembly 106 associated with a derrick 114 positioned on or
adjacent to the rig 104 or offshore platform 142. The lift assembly
106 may include a hook 110, a cable 108, a traveling block (not
shown), and a hoist (not shown) that cooperatively work together to
lift or lower a swivel 116 that is coupled an upper end of the tool
string 128. The tool string 128 may be raised or lowered as needed
to add additional sections of tubing to the tool string 128 to
position the distal end of the tool string 128 at the downhole
location 136 in the wellbore 130.
[0023] An illustrative embodiment of a coupling assembly 100 that
may be used to couple together tubing segments in a tool string is
described in more detail with regard to FIGS. 2-6. Each coupling
assembly 100 includes a first mandrel 204 and a second mandrel 206
joined by a coupler 202 at a first end 230 of the first mandrel 204
and a second end 232 of the second mandrel 206. Each mandrel may
form a portion of a segment of a tool string.
[0024] The coupler 202 includes a threaded interface about an
internal surface of the coupler 202 to engage the first mandrel 204
and second mandrel 206. In an embodiment, the coupler 202 includes
a first internal thread 210 on a first end 236 of the coupler 202
and a second internal thread 212 on a second end 238 of the coupler
202. The first internal thread 210 engages a first external thread
218 of the first mandrel 204 and the second internal thread 212
engages a second external thread 226 of the second mandrel 206.
[0025] In some embodiments, the first internal thread 210 and the
second internal thread 212 have different thread pitches. In such
embodiments, the first external thread 218 is complementary to and
engages the first internal thread 210 and the second external
thread 226 is complementary to and engages the second internal
thread 212.
[0026] One or more aligning pins 216 are inserted into first
mandrel aligning holes 219 and second mandrel aligning holes 217.
In the embodiment illustrated in FIG. 2, the aligning pin 216 is an
aligning pin that is configured to engage a first mandrel aligning
hole 219 and a second mandrel aligning hole 217 to align the first
mandrel 204 with respect to the second mandrel 206, and to restrict
axial movement of the first mandrel 204 with respect to the second
mandrel 206 once the first mandrel 204 and second mandrel 206 are
engaged. In some embodiments, the coupling assembly 100 further
includes one or more port interfaces 220. Each port interface 220
couples a first conduit 221 of the first mandrel 204 to a second
conduit 222 of the second mandrel. The first conduit 221 and second
conduit 222 may be a hydraulic conduit, wire conduit, or other
suitable conduit for conveying a hydraulic or electrical line, such
as a control line. The port interface may be an interface of a male
connector of the first conduit 221 coupled to a female connector of
the second conduit 222, or vise versa. In such embodiments, the
port interface 220 forms an electrical or hydraulic coupling
between the first mandrel 204 and second mandrel 206.
[0027] In some embodiments, the coupling assembly 100 further
includes a locking mechanism 240, such as a locknut, positioned
adjacent to the first end 236 or the second end 238 of the coupler
202. The locking mechanism 240 has a threaded interface 242 to
engage the first mandrel 204 or second mandrel 206 and to prevent
longitudinal motion of the coupler 202 with respect to the first
mandrel 204 or the second mandrel 206. In one of such embodiments,
multiple locking mechanisms (not shown) are positioned adjacent to
both the first end 236 and the second end 238 of the coupler 202 to
secure the coupler 202 and to prevent longitudinal motion of with
respect to the first or the second mandrels 204 and 206.
[0028] FIG. 3 shows a portion of an exemplary coupler 202 used in
the coupling assembly 100. The coupler 202 includes the first
internal thread 210, which is configured to engage the first
external thread 218 of the first mandrel 204, and the second
internal thread 212, which is configured to engage the second
external thread 226 of the second mandrel 206. The coupler 202 also
includes a plurality of visual indicators 265 that indicate the
position of the coupler 202 with respect to the first mandrel 204
and second mandrel 206. In some embodiments, the first mandrel 204
and second mandrel 206 also include visual indicators, which when
aligned with the visual indicators 265 of the coupler 202, indicate
that the first mandrel 204 and second mandrel 206 are aligned with
each other. The coupler 202 also includes a window 260. The window
260 may be a radial slot that is either open or filled with a
transparent material to allow an operator to visually inspect the
area surrounded by the coupler 202 to determine whether the first
mandrel 204 and second mandrel 206 are aligned.
[0029] FIG. 4A shows an embodiment of a first end 230 of the first
mandrel 204, as shown in the coupling assembly 100 of FIG. 2. The
first end 230 includes the first external thread 218 for engaging
the first internal thread 210 of the coupler 202. The first end 230
also includes the openings of the first conduits 221 having port
interfaces 220 and first mandrel aligning holes 219 for receiving
aligning pins 216. The first end 230 also includes a first visual
indicator 266. The first conduits 221 and first mandrel aligning
holes 219 are positioned about the periphery of the first mandrel
to provide a desired number of aligning interfaces and port
interfaces 220.
[0030] The first visual indicator 266 may be a milled, etched,
painted, or otherwise marked radial line, on the outer surface of
the first mandrel 204 at a first, predetermined distance from the
first end 230 of the first mandrel 204. In the embodiment of FIG.
4A, the first visual indicator 266 marks the position of aligning
pin 216 and provides a means to identify a location of the aligning
pin 216 when the first mandrel 204 is engaged to the coupler 202
and the aligning pin 216 hidden from view by the coupler 202.
[0031] FIG. 4B shows an embodiment of a second mandrel 206, as
shown in the coupling assembly 100 of FIG. 2, and more
particularly, a second end 232 of the second mandrel 206. The
second end 232 of the second mandrel 206 includes the second
external thread 226 for engaging the second internal thread 212 of
the coupler 202. The second end 232 also includes the openings of
the second conduits 222 having port interfaces 220 and second
mandrel aligning holes 217 for receiving aligning pins 216. The
second end 232 also includes a second visual indicator 267. The
second conduits 222 and second mandrel aligning holes 217 are
positioned about the periphery of the second mandrel 206 to provide
a desired number of aligning interfaces and port interfaces
220.
[0032] The second visual indicator 267, similar to the first visual
indicator 266, may be a milled, etched, painted, or otherwise
marked radial line, on the outer surface of the second mandrel 206
at a first, predetermined distance from the second end 232 of the
second mandrel 206. In some embodiments, the second visual
indicator 267 provides a visual indication of a location of one of
the second mandrel aligning holes 217 of the second mandrel 206. In
other embodiments, the first and second visual indicators 266 and
267 provide a visual indication that the first mandrel 204 and
second mandrel 206 are aligned. As such, the first and second
visual indicators 266 and 267 provide readily identifiable
alignment indications even when view of the aligning pins 216 and
port interfaces 220 are hidden from view by the coupler 202.
[0033] FIG. 5A illustrates a cross-section view of the first
external thread 218 of the first mandrel 204 of FIG. 4A engaged to
the first internal thread 210 of the coupler 202 of FIG. 3. FIG. 5B
illustrates a cross-section view of a portion of a second external
thread 226 of the second mandrel 206 of FIG. 4B engaged to a second
internal thread of the coupler of FIG. 3. In the embodiment
illustrated in FIG. 5A, the first internal thread 210 and first
external thread 218 have a thread pitch that is greater than the
thread pitch of the second internal thread 212 and second external
thread 226. For example, the first internal thread 210 and first
external thread 218 may have a thread pitch of approximately three
threads per inch while the second internal thread 212 and second
external thread 226 may have a thread pitch of approximately two
threads per inch. In such an embodiment, turning of the coupler 202
would result in the he second internal thread 212 and second
external thread 226 advancing (along a longitudinal axis of the
coupler 202) at approximately 1.5 times the rate of retreat of the
first internal thread 210 and the first external thread 218.
[0034] In the embodiment illustrated in FIGS. 5A and 5B, the first
external thread 218 and the second external thread 226 have a
reverse lead angle .alpha., which may be, for example, negative
seven degrees taken from a base line that is perpendicular to the
longitudinal axis of the first mandrel 204 or second mandrel 206.
The negative flank angle results in the coupler 202 being drawn
inward to compress the coupling assembly 100 when an axial tensile
load is applied to the coupling assembly 100 through a tool string
that includes the assembly. Further, the first external thread 218
and second external thread may have a trailing flank angle of
.theta., which may be, for example, approximately forty-five
degrees. This configuration directs loads generated from axial
loads experienced at the coupling of the first and second external
threads 218 and 226 with the first and second internal threads 210
and 212 inwards and towards the longitudinal axis of the first
mandrel 204 and second mandrel 206, respectively. In other
embodiments, the first and second external threads have a reverse
lead angle .alpha. of approximately negative three to negative
thirty degrees and a trailing flank angle .theta. of approximately
thirty to sixty degrees to accommodate a variety of factors such as
the tensile load of the first mandrel 204 and second mandrel 206,
the length of the coupler 202, the thread pitch and thread profile
of the external and internal threads 218, 226, 210, and 212, and
the material composition of the first mandrel 204 and second
mandrel 206 and the coupler 202.
[0035] An illustrative method of assembling the foregoing parts of
the coupling assembly 100 is described with regard to FIG. 6. The
method includes axially aligning the first end 230 of the first
mandrel 204 with the second end 232 of the second mandrel 206. This
first and second ends 230 and 232 may be axially aligned by
aligning the first visual indicator 266 with the second visual
indicator 267. Once the first mandrel 204 and second mandrel 206
are axially aligned with each other, the first mandrel 204 and
second mandrel 206 are then held in place to prevent axial motion.
The method also includes threading the first internal thread 210 of
the coupler 202 onto the first external thread 218 of the first
mandrel 204 to engage the first end 230 of the first mandrel 204
with the first end 236 of the coupler 202. The rate at which the
first mandrel 204 engages with and disengages from the coupler 202
at a first engagement rate that is based on the thread pitch of the
first external thread 218 and first internal thread 210.
[0036] The second internal thread 212 of the coupler 202 is then
threaded to the second external thread 226 of the second mandrel
206 to engage the second end 232 of the second mandrel 206 with the
second end 238 of the coupler 202. Given that the first mandrel 204
is already engaged to the coupler 202, threading the coupler 202 to
the second mandrel 206 causes the first mandrel 204 to disengage
from the coupler 202 at the first engagement rate.
[0037] The differential pitch between the first internal thread 210
and second internal thread 212, however, induces the second mandrel
206 to axially engage the coupler 202 at a second engagement rate
that is different than the first engagement rate (or disengagement
rate of the first mandrel 204). For example, if the pitch of the
first internal thread 210 and first external thread 218 is
approximately three threads per inch while the thread pitch of the
second internal thread 212 and second external thread 226 is
approximately two threads per inch, then the coupler 202 will
engage the second mandrel 206 approximately fifty percent faster
than the coupler 202 will disengage from the first mandrel 204,
thereby resulting in the first mandrel 204 moving toward the second
mandrel 206 if the coupler 202 is turned while the first mandrel
204 and second mandrel 206 are constrained from rotating. In an
embodiment, the first mandrel 204 and second mandrel 206 are
constrained from rotating relative to one another by aligning pins
216.
[0038] The foregoing method induces the second mandrel 206 to move
towards the first mandrel 204 until the first end 230 of the first
mandrel 204 is engaged to the second end 232 of the second mandrel
206. The method may further include visually or optically
inspecting the interface between the first mandrel 204 and second
mandrel via the window 260 to determine if the first mandrel 204 is
aligned with the second mandrel 206.
[0039] The above-disclosed embodiments have been presented for
purposes of illustration and to enable one of ordinary skill in the
art to practice the disclosure, but the disclosure is not intended
to be exhaustive or limited to the forms disclosed. Many
insubstantial modifications and variations will be apparent to
those of ordinary skill in the art without departing from the scope
and spirit of the disclosure. For instance, although the flowcharts
depict a serial process, some of the steps/processes may be
performed in parallel or out of sequence, or combined into a single
step/process. The scope of the claims is intended to broadly cover
the disclosed embodiments and any such modification. Further, the
following clauses represent additional embodiments of the
disclosure and should be considered within the scope of the
disclosure:
[0040] Clause 1, a differential threaded coupling system
comprising: a first mandrel having a first external thread about an
external surface of the first mandrel; a second mandrel having a
second external thread about an external surface of the second
mandrel; a coupler comprising a first internal thread that
complements the first external thread of the first mandrel and a
second internal thread that complements the second external thread
of the second mandrel; and an aligning pin configured to engage a
first aligning hole of the first mandrel and a second aligning hole
of the second mandrel to restrict axial rotation between the first
mandrel and the second mandrel when the first mandrel is engaged to
the second mandrel.
[0041] Clause 2, the coupling system of clause 1, wherein each
tooth of the first external thread and second external thread has a
reverse lead flank angle of approximately -3 to -30 degrees and a
trailing flank angle of approximately 30 to 60 degrees.
[0042] Clause 3, the coupling system of clause 2, wherein the
reverse lead angle is approximately -7 degrees and the trailing
flank angle is approximately 45 degrees.
[0043] Clause 4, the coupling system of any of clauses 1-3, wherein
the first external thread and first internal thread have a first
thread pitch and the second internal thread and second external
thread have a second thread pitch, the second thread pitch being
less than the first thread pitch, such that rotation of the coupler
results in an engagement rate of the coupler to the second mandrel
that is greater than a disengagement rate of the coupler to the
first mandrel.
[0044] Clause 5, the coupling system of any of clauses 1-4, further
comprising a plurality of port interfaces, each port interface
forming a coupling between a first conduit of the first mandrel and
a second conduit of the second mandrel.
[0045] Clause 6, the coupling system of any of clauses 1-5, wherein
the plurality of port interfaces comprises an electrical connector,
and wherein the electrical connector is coupled to a first conduit
comprising an electrical conduit, and a second conduit comprising
an electrical conduit.
[0046] Clause 7, the coupling system of any of clauses 1-6, wherein
the plurality of port interfaces comprises a hydraulic connector,
and wherein the hydraulic connector is coupled to a first conduit
comprising a fluid conduit, and a second conduit comprising a fluid
conduit.
[0047] Clause 8, the coupling system of any of clauses 1-7, wherein
the coupler comprises a window for viewing the first mandrel and
second mandrel when the first and second mandrels are coupled to
the coupler.
[0048] Clause 9, a method of coupling a first mandrel to a second
mandrel, the method comprising: aligning a first end of a first
mandrel to a second end of a second mandrel, the first mandrel
having a first external thread about an external surface of the
first mandrel and the second mandrel having a second external
thread about an external surface of the second mandrel; threading a
coupler to the first mandrel to engage a first internal thread of
the coupler to the first external thread of the first mandrel,
wherein the first internal thread and first external thread have a
first thread pitch; threading the coupler to the second mandrel to
engage a second internal thread of the coupler to the second
external thread of the second mandrel, wherein the second internal
thread and second external thread have a second thread pitch,
wherein the second thread pitch is less than the first thread
pitch, such that rotating the coupler relative to the first mandrel
and second mandrel simultaneously results in the coupler engaging
the second mandrel at a faster rate than the coupler disengages the
first mandrel, and the second mandrel being drawn towards the first
mandrel until the first end of the first mandrel engages the second
end of the second mandrel.
[0049] Clause 10, the method of clause 9, wherein aligning the
first end of the first mandrel to the second end of the second
mandrel comprises aligning an aligning pin with a first aligning
hole of the first mandrel and a second aligning hole of the second
mandrel, wherein the aligning pin is configured to restrict axial
rotation between the first mandrel and the second mandrel when the
first mandrel is engaged to the second mandrel.
[0050] Clause 11, the method of any of clauses 9 and 10, wherein
aligning the first end of the first mandrel to the second end of
the second mandrel comprises aligning a plurality of port
interfaces, the method further comprising coupling a first conduit
of the first mandrel to a second conduit of the second mandrel at
each of the plurality of port interfaces.
[0051] Clause 12, the method of any of clauses 9-11, wherein the
plurality of port interfaces comprises an electrical connector, and
wherein each electrical connector is coupled to a first conduit
comprising an electrical conduit, and a second conduit comprising
an electrical conduit.
[0052] Clause 13, the method of any of clauses 9-12, wherein the
plurality of port interfaces comprises a hydraulic connector, and
wherein each hydraulic connector is coupled to a first conduit
comprising a fluid conduit, and a second conduit comprising a fluid
conduit.
[0053] Clause 14, the method of any of clauses 9-13, further
comprising aligning a first visual indicator of the first mandrel
to a second visual indicator of the second mandrel to align the
first end of the first mandrel to the second end of the second
mandrel.
[0054] Clause 15, the method of any of clauses 9-14, further
comprising visually determining if the first end of the first
mandrel is aligned with the second end of the second mandrel by
observing the first mandrel and second mandrel through a window of
the coupler.
[0055] Clause 16, the method of any of clauses 9-15, wherein each
of the first external thread and second external thread has a
reverse lead flank angle of approximately -3 to -30 degrees and a
trailing flank angle of approximately 30 to 60 degrees.
[0056] Clause 17, the method of clause 16, wherein the reverse lead
angle is approximately -7 degrees and the trailing flank angle is
approximately 45 degrees.
[0057] Clause 18, a coupler comprising: a cavity having a first end
for receiving a first mandrel and a second end for receiving a
second mandrel; a first internal thread at the first end, the first
internal thread having a thread profile that complements a first
external thread of the first mandrel, wherein the first internal
thread and first external thread have a first thread pitch; and a
second internal thread having a thread profile that complements a
second external thread of the second mandrel, wherein the second
internal thread and second external thread have a second thread
pitch, the second thread pitch being less than the first thread
pitch such that rotating the coupler relative to the first mandrel
and second mandrel simultaneously results in the coupler engaging
the second mandrel at a faster rate than the coupler disengages the
first mandrel.
[0058] Clause 19, the coupler of clause 18, further comprising a
window to provide a view of the first mandrel and second mandrel
when the first mandrel and second mandrel are engaged by the
coupler.
[0059] Clause 20, the coupler of any of clauses 18 and 19, further
comprising at least one visual indicator indicative of a rotational
position of the coupler with respect to at least one of the first
mandrel and the second mandrel.
[0060] Unless otherwise specified, any use of any form of the terms
"connect," "engage," "couple," "attach," or any other term
describing an interaction between elements in the foregoing
disclosure is not meant to limit the interaction to direct
interaction between the elements and may also include indirect
interaction between the elements described. As used herein, the
singular forms "a", "an" and "the" are intended to include the
plural forms as well, unless the context clearly indicates
otherwise. Unless otherwise indicated, as used throughout this
document, "or" does not require mutual exclusivity. It will be
further understood that the terms "comprise" and/or "comprising,"
when used in this specification and/or the claims, specify the
presence of stated features, steps, operations, elements, and/or
components, but do not preclude the presence or addition of one or
more other features, steps, operations, elements, components,
and/or groups thereof. In addition, the steps and components
described in the above embodiments and figures are merely
illustrative and do not imply that any particular step or component
is a requirement of a claimed embodiment.
[0061] It should be apparent from the foregoing that embodiments of
an invention having significant advantages have been provided.
While the embodiments are shown in only a few forms, the
embodiments are not limited but are susceptible to various changes
and modifications without departing from the spirit thereof.
* * * * *