U.S. patent application number 14/135314 was filed with the patent office on 2014-06-26 for method and apparatus for downhole installation of coiled tubing strings.
The applicant listed for this patent is Chad Barber, Denis Gilbert, Arnoud Struyk. Invention is credited to Chad Barber, Denis Gilbert, Arnoud Struyk.
Application Number | 20140174749 14/135314 |
Document ID | / |
Family ID | 50972926 |
Filed Date | 2014-06-26 |
United States Patent
Application |
20140174749 |
Kind Code |
A1 |
Barber; Chad ; et
al. |
June 26, 2014 |
METHOD AND APPARATUS FOR DOWNHOLE INSTALLATION OF COILED TUBING
STRINGS
Abstract
A tool for releasably coupling a coiled tubing string to a
primary tubing string includes: a tool body for coupling to a
downstream end of the primary tubing string, the tool body
comprising a locking mechanism for selectively coupling a coiled
tubing end joint to the tool body, the locking mechanism being
unlockable in response to fluid pressure inside the tool body
exceeding a first threshold; a wellbore access mechanism openable
in response to fluid pressure inside the tool exceeding a second
threshold.
Inventors: |
Barber; Chad; (Calgary,
CA) ; Gilbert; Denis; (Calgary, CA) ; Struyk;
Arnoud; (Calgary, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Barber; Chad
Gilbert; Denis
Struyk; Arnoud |
Calgary
Calgary
Calgary |
|
CA
CA
CA |
|
|
Family ID: |
50972926 |
Appl. No.: |
14/135314 |
Filed: |
December 19, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61740371 |
Dec 20, 2012 |
|
|
|
Current U.S.
Class: |
166/319 ;
166/242.6 |
Current CPC
Class: |
E21B 17/021 20130101;
E21B 23/02 20130101; E21B 17/02 20130101; E21B 17/20 20130101; E21B
17/043 20130101; E21B 23/00 20130101 |
Class at
Publication: |
166/319 ;
166/242.6 |
International
Class: |
E21B 23/00 20060101
E21B023/00; E21B 17/02 20060101 E21B017/02 |
Claims
1. A tool for releasably coupling a coiled tubing string to a
primary tubing string, the tool comprising: a tool body for
coupling to a downstream end of the primary tubing string, the tool
body comprising a locking mechanism for selectively coupling a
coiled tubing end joint to the tool body, the locking mechanism
being unlockable in response to fluid pressure inside the tool body
exceeding a first threshold; a wellbore access mechanism openable
in response to fluid pressure inside the tool exceeding a second
threshold.
2. The tool of claim 1, wherein the wellbore access mechanism is
located upstream of the tool body.
3. The tool of claim 1, comprising a rotating shear joint coupled
to the coiled tubing end joint for receiving an end of the coiled
tubing string.
4. The tool of claim 1, comprising a clamp coupled to a coupler of
the primary tubing string, the clamp for receiving the coiled
tubing string at a location along a length of the primary tubing
string.
5. The tool of claim 1, wherein the tool body comprises: a first
end for coupling to a primary tubing string; a second end for
coupling to a primary tubing end joint; an inner surface defining a
channel and first and second bores, the channel for receiving fluid
from an outlet of the primary tubing string, the first and second
bores being in fluid communication with the channel through
openings located adjacent an upstream end of the first and second
bores; and a coiled tubing string support for receiving an end
joint of the coiled tubing string; first and second pistons
slidably received in the first and second bores; first and second
cams coupled to the outer surface of a tool body housing at
locations circumferentially spaced on either side of the coiled
tubing string support, the first and second cams being movable
between a locked position in which the cams abut an upstream side
of a radially extending structure of the coiled tubing string end
joint and an unlocked position in which the first and second cams
are radially spaced from the radially extending structure, the
first and second cams being biased toward the locked position and
being movable in response to movement of the first and second
pistons; wherein when fluid pressure within the tool body exceeds
the first threshold, the first piston and the second piston are
actuated to move the first cam and the second cams to the unlocked
position for releasing the coiled tubing string and when the fluid
pressure within the tool body exceeds the second threshold, the
channel of the tool body being opened.
6. The tool of claim 1, wherein the tool body comprises: a coiled
tubing receiving channel for receiving a downstream portion of the
coiled tubing end joint; a first end for coupling to a transition
member, the transition member for receiving an upstream portion of
the coiled tubing end joint to direct the coiled tubing end joint
into the coiled tubing receiving channel; first and second bores
for receiving fluid from an outlet of the primary tubing string,
first and second pistons slidably received in the first and second
bores; first and second cams coupled to the outer surface of the
housing at locations circumferentially spaced on either side of the
coiled tubing string support, the first and second cams being
movable between a locked position in which the cams abut an
upstream side of a radially extending structure of the coiled
tubing string end joint and an unlocked position in which the first
and second cams are radially spaced from the radially extending
structure, the first and second cams being biased toward the locked
position and being movable in response to movement of the first and
second pistons; wherein when fluid pressure within the tool body
exceeds the first threshold, the first piston and the second piston
are actuated to move the first cam and the second cams to the
unlocked position for releasing the coiled tubing string.
7. The tool of claim 6, wherein the first and second bores receive
fluid through a pressure line for communicating with the outlet,
the pressure line extending through the transition member.
8. The tool of claim 1, wherein the wellbore access mechanism
comprises: a fitting for coupling to a downstream end of the
primary tubing string, the fitting comprising slots extending
through a wall of the fitting; a piston slidable though a channel
of the fitting between a first position in which communication
between the channel and the wellbore is blocked and a second
position in which communication between the channel and the
wellbore is open; and shear pins coupling the piston to the
fitting; wherein the shear pins fail in response to the fluid
pressure exceeding the second threshold to release the piston to
the second position.
9. The tool of claim 1, comprising a transition member between the
tool body and the wellbore access mechanism, the transition member
for transitioning the coiled tubing end joint into a position
within the tool body.
10. The tool of claim 1, wherein the tool body is
bullnose-shaped.
11. The tool of claim 5, wherein the first and second pistons are
fitted with snap rings.
12. The tool of claim 6, wherein the first and second pistons are
fitted with snap rings.
13. A clamp assembly for coupling a coiled tubing string to a
primary tubing string, the clamp assembly comprising; a coupler for
coupling adjacent primary tubing members of the primary tubing
string to one another; a clamp coupled to the coupler, the clamp
comprising a hinge and a bracket located opposite the hinge, the
bracket for receiving the coiled tubing string; wherein the bracket
is sized for limiting non-axial movement of the coiled tubing
string relative to the primary tubing string.
14. The clamp assembly of claim 13, wherein the clamp comprises
cutouts for receiving axially extending projections of the coupler
to couple the clamp to the primary tubing string.
15. The clamp assembly of claim 13, wherein the clamp assembly is
openable for receiving the primary tubing string by pivoting first
and second clamp members about a hinge pin of the hinge.
16. The clamp assembly of claim 14, comprising a second clamp
coupled to axially extending projections extending from an opposite
end of the coupler.
17. The clamp assembly of claim 14, wherein the axially extending
projections comprise circumferentially extending openings for
receiving fasteners to couple the clamp to the coupler.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to methods and apparatus for
downhole installation of coiled tubing strings.
BACKGROUND
[0002] Coiled tubing strings are installed adjacent to primary
tubing strings in wellbores for many different applications. Sensor
instrumentation, such as thermocouples or pressure sensors, for
example, may be housed in coiled tubing strings. Coiled tubing
strings may also be used in chemical injection or steam injection
applications.
[0003] Coiled tubing strings have a relatively small diameter,
which causes the coiled tubing strings to be flexible and,
therefore, easily damaged during installation. Damage to the coiled
tubing typically occurs when the tubing is pushed down from the
surface into a vertical section of a horizontal well. Because
coiled tubing installations may be up to 1500 m in length,
sinusoidal or helical buckling often occurs. In addition, excessive
force applied when pushing the coiled tubing downhole often results
in damage to the coiled tubing string particularly at excessive dog
leg severity, upset or coupling locations.
[0004] When coiled tubing is damaged during installation, the
tubing may be unusable for the immediate installation and/or for
subsequent installations, particularly when the tubing breaks or
fails. In some cases, damage caused during installation is not
discovered immediately and the coiled tubing is operational for a
time. For example, thermocouples or other downhole sensors may
operate for a time and then fail. When the tubing is pulled to the
surface, it may be discovered that the thermocouple failure is a
result of damage that occurred during installation.
[0005] Improvement in methods and apparatus for downhole
installation of coiled tubing is therefore desirable.
SUMMARY
[0006] In an aspect of the present disclosure there is provided, a
tool for releasably coupling a coiled tubing string to a primary
tubing string, the tool including a locking mechanism for securing
the coiled tubing string to the primary tubing string, the locking
mechanism being releasable to de-couple the coiled tubing string
from the primary tubing string in response to a first threshold
pressure being reached; wherein a portion of the primary tubing
string is openable to enable communication between a channel of the
primary tubing string and the wellbore in response to a second,
higher, threshold pressure being reached.
[0007] In another aspect of the present disclosure there is
provided a tool for releasably coupling a coiled tubing string to a
primary tubing string, the tool comprising: a tool body for
coupling to a downstream end of the primary tubing string, the tool
body comprising a locking mechanism for selectively coupling a
coiled tubing end joint to the tool body, the locking mechanism
being unlockable in response to fluid pressure inside the tool body
exceeding a first threshold; a wellbore access mechanism openable
in response to fluid pressure inside the tool exceeding a second
threshold.
[0008] In still another aspect of the present disclosure there is
provided a clamp assembly for coupling a coiled tubing string to a
primary tubing string, the clamp assembly comprising; a coupler for
coupling adjacent primary tubing members of the primary tubing
string to one another; a clamp coupled to the coupler, the clamp
comprising a hinge and a bracket located opposite the hinge, the
bracket for receiving the coiled tubing string; wherein the bracket
is sized for limiting non-axial movement of the coiled tubing
string relative to the primary tubing string.
DRAWINGS
[0009] The following figures set forth embodiments of the invention
in which like reference numerals denote like parts. Embodiments of
the invention are illustrated by way of example and not by way of
limitation in the accompanying figures.
[0010] FIG. 1 is an isometric view of a tool according to an
embodiment for coupling a coiled tubing string to a primary tubing
string;
[0011] FIG. 2 is another isometric view of the tool of FIG. 1 with
a tool body and downstream housing removed;
[0012] FIG. 3 is another isometric view of the tool of FIG. 1 with
a cover and downstream housing removed;
[0013] FIG. 4 is another isometric view of the tool of FIG. 1 with
the tool body and downstream housing shown as transparent;
[0014] FIG. 5 is an isometric view of a the tool body of the tool
of FIG. 1;
[0015] FIG. 6 is another isometric view of the tool as shown in
FIG. 3;
[0016] FIG. 7 is another isometric view of the tool as shown in
FIG. 2;
[0017] FIG. 8 is an isometric view of the tool as shown in FIG. 2
with the coiled tubing string released;
[0018] FIG. 9 is yet another isometric view of the tool as shown in
FIG. 2;
[0019] FIG. 10 is an isometric sectional view of a tool for
coupling a coiled tubing string to a primary tubing string
according to another embodiment;
[0020] FIG. 11 is an isometric sectional view of a portion of the
tool of FIG. 10;
[0021] FIG. 12 is an isometric side view of the tool of FIG. 10
with a transition member of the tool shown as transparent;
[0022] FIG. 13 is an isometric top view of the tool of FIG. 10 with
the transition member of the tool shown as transparent;
[0023] FIG. 14 is an isometric view of a rotating shear joint;
[0024] FIG. 15 is an exploded side view of the rotating shear joint
of FIG. 14;
[0025] FIG. 16 is an isometric view of a portion of a primary
tubing string and a coiled tubing string according to an
embodiment;
[0026] FIG. 17A is an isometric view of a coupler of a primary
tubing string;
[0027] FIG. 17B is a side view of the coupler of FIG. 17A;
[0028] FIG. 18A is an isometric view of a clamp according to an
embodiment;
[0029] FIG. 18B is an end view of the clamp of FIG. 18A; and
[0030] FIG. 19 is an isometric view of a portion of an end joint
according to an embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0031] Numerous details are set forth to provide an understanding
of the embodiments described herein. The embodiments may be
practiced without these details. In other instances, well-known
methods, procedures, and components have not been described in
detail to avoid obscuring the embodiments described.
[0032] Referring to FIG. 1, a tool 10 for releasably coupling a
coiled tubing string 12 to a primary tubing string 14 is generally
shown. In the example described herein, the coiled tubing string 12
has a diameter of approximately 1.25 inches; however, the tool may
be used with any commercially available coiled tubing.
[0033] As shown in FIG. 2, a coiled tubing end joint 16 is coupled
to an end of the coiled tubing string 12. The coiled tubing end
joint 16 includes an upstream portion 18, a reduced diameter
portion 20 and an end portion 22, which has a diameter that is
generally equal to the diameter of the upstream portion 18. The
upstream portion 18 is coupled to an end of the coiled tubing
string 12 by a welded connection, for example. A step including a
radially extending wall 24 is provided between the cylindrical
portion 20 and the end portion 22. It will be appreciated by a
person skilled in the art that the coiled tubing end joint 16 is
not limited to the configuration shown. The coiled tubing end joint
16 functions to close the end of the coiled tubing string 12 and
provide a structure that is engageable by the tool 10 as will be
described. Any arrangement that achieves both functions in a single
part or multiple parts may be used. Further, in some applications,
the end of the coiled tubing string 12 may be open. In such
applications, the end thereof may include an outwardly extending
flange, a collar or a groove that is engageable by the tool 10.
[0034] Referring back to FIG. 1, the tool 10 is assembled between
the primary tubing string 14 and a primary tubing end joint 26. The
primary tubing end joint 26 includes a rupture disc 28 that is
rupturable to open the primary tubing end joint 26 when pressure
inside the primary tubing end joint 26 exceeds a second threshold.
It will be appreciated by a person skilled in the art that the
rupture disc 28 may be replaced with any wellbore access mechanism
that opens communication to the primary tubing string 14 in
response to pressure inside the primary tubing end joint 26
exceeding a second threshold.
[0035] The tool 10 includes a tool body 30, a cover 32 and upstream
and downstream housings 34 and 36, respectively. The upstream and
downstream housings 34, 36 are coupled to the tool body 30 using
set screws 45. The upstream and downstream housings 34, 36 are
shaped to provide upstream and downstream tapers so that the tool
10 does not get caught on objects encountered downhole during
deployment or retrieval of the tool 10.
[0036] Referring also to FIG. 3, the tool body 30 includes a
support for receiving the coiled tubing end joint 16. In the
present example, the support is a tube-shaped portion 38 of the
tool body 30 that includes a coiled tubing-receiving channel 35
(shown in FIG. 5) sized to slidably receive the coiled tubing end
joint 16 of the coiled tubing string 12. When received in the
coiled tubing-receiving channel of the tube-shaped portion 38, a
downstream surface 40 (shown in FIG. 2) of the end portion 22 of
the coiled tubing end joint 16 abuts a plug 42. The plug 42 is
coupled to the tube-shaped portion 38 of the tool body 30 by a
threaded connection and functions as a stop to limit downstream
movement of the coiled tubing string 12 relative to the tool
10.
[0037] Referring to FIGS. 4 and 5, the tool body 30 further
includes a channel 44, which is defined by an inner surface 46 of
the tool body 30 and extends through a length of the tool 10. The
tool body 30 is coupled by threaded connections to an end 48 of the
primary tubing string 14 and an end 50 of the primary tubing end
joint 26. The tool body 30 further includes a first bore 52 and a
second bore 54. The bores 52, 54 are located on either side of the
tube-shaped portion 38 adjacent to the channel 44. Plugs 56 and 58
are received in upstream ends 60 and 62 of the first and second
bores 52, 54, respectively, to seal the upstream ends 60, 62 of the
bores 52, 54.
[0038] The first and second bores 52, 54 are sized to slidably
receive first and second pistons 64 and 66, respectively, of a
locking mechanism. Downstream ends 70, 72 of the pistons 64, 66
extend through openings in a wall 68 of the tool body 30 and seals
are provided between the wall 68 and the pistons 64, 66. A first
opening 74 extends between the channel 44 and the first bore 52 and
a second opening 76 extends between the channel 44 and the second
bore 54. The openings 74, 76 allow for fluid communication between
the channel 44 and the bores 52, 54.
[0039] Referring also to FIGS. 6 and 7, a first cam support 78 and
a second cam support 80 are coupled to an outer surface 82 of the
tool body 30. In the present example, the cam supports 78, 80 are
received in machined pockets that are provided in the outer surface
82 of the tool body 30. The cam supports 78, 80 may alternatively
be coupled by welding or the tool body 30 may be machined to
include cam support structures on the outer surface 82 thereof. The
first and second cam supports 78, 80 are located on either side of
the tube-shaped portion 38 of the tool body 30 and are oriented to
allow first and second cams 84, 86, which are pivotally coupled
thereto by first and second bolts 88, 90, to pivot into and out of
contact with the radially extending wall 24 of the coiled tubing
end joint 16 though openings 85 in the tool body 30. The cams 84,
86 are generally boot-shaped and each cam includes an upstream
surface 92 at the heel, a downstream surface 94 at the toe and an
axially extending surface 95 therebetween (shown in FIG. 9). First
and second springs 96, 98 are coupled to the cam supports 78, 80 to
bias the downstream surfaces 94 of the cams 84, 86 toward the
coiled tubing end joint and into contact with the radially
extending wall 24. The downstream ends 70, 72 of the pistons 64, 66
include arms 100, 102 (shown in FIG. 9), which abut the upstream
surfaces 92 of the cams 84, 86. Downstream movement of the pistons
64, 66 causes the cams 84, 86 to pivot out of contact with the
radially extending wall 24 into an unlocked position in which the
coiled tubing end joint 16 is released. The unlocked position is
shown in FIG. 8.
[0040] In order to assemble the tool 10, the tool body 30 is
threaded onto the end 48 of the primary tubing string 14 and the
primary tubing end joint 26 is threaded onto the opposite end of
the tool body 30. The upstream housing portion 34, which is
received on the primary tubing string 14, and the downstream
housing portion 36, which is received on the primary tubing end
joint 26, are then secured to the tool body 30 using set screws.
The end portion 22 of the coiled tubing end joint 16 is then pushed
into the coiled tubing-receiving channel until the end surface 40
of the coiled tubing end joint 16 abuts the plug 42. The end
portion 22 forces the cams 84, 86 of the locking mechanism to pivot
away from the coiled tubing string 12 as the coiled tubing end
joint 16 advances and when the end portion 22 moves beyond the cams
84, 86, the cams 84, 86 are biased into abutment with the coiled
tubing end joint 16. When the coiled tubing string 12 is secured to
the primary tubing string 14 by the tool 10, the cams 84, 86 are in
the locked position in which the downstream surfaces 94 of the cams
84, 86 abut the radially extending wall 24 of the coiled tubing end
joint 16 and the axially extending surfaces 95 abut the cylindrical
portion 20 of the coiled tubing end joint 16. In embodiments in
which the radially extending wall is larger, the axially extending
surfaces 95 may be spaced from the cylindrical portion when the
cams 84, 86 are in the locked position.
[0041] In operation, after the coiled tubing string 12 has been
secured to the primary tubing string 14 by the tool 10, the primary
tubing string 14 is fed down a wellbore. When an installation
location has been reached, fluid, such as water, for example, is
pumped through the primary tubing 14. The fluid enters the channel
44 of the tool body 30 of the tool 10 and the tubing end joint 26.
Because the tubing end joint 26 is sealed by the rupture disc 28,
fluid is forced through the openings 74, 76 into the bores 52, 54
and pressure within the bores 52, 54 increases. When the pressure
in the bores 52, 54 reaches a first threshold, the pistons 64, 66
are actuated to pivot the cams 84, 86 to an unlocked position in
which the cams 84, 86 no longer engage the coiled tubing end joint
16. The coiled tubing string 12 may then be retracted from the tool
10. Fluid continues to be pumped into the primary tubing string 14
and when the pressure reaches a second threshold, the rupture disc
28 ruptures to open communication between the primary tubing string
14 and the wellbore. The primary tubing string 14 and the coiled
tubing string 12 are then ready for use.
[0042] In the present example, the first threshold pressure is
approximately 700 psi and the second threshold pressure is
approximately 2000 psi. The thresholds are approximate and are
determined based on the specifications of the rupture disc 28 and
the specifications of the tool 10.
[0043] It will be appreciated by a person skilled in the art that
the tool described herein is provided by way of example. Other tool
configurations are possible. In general, any tool including a
locking mechanism for securing the coiled tubing string to the
primary tubing string that is actuable to release the coiled tubing
string from the primary tubing string in response to a first
threshold pressure within the tool and a channel that is openable
to enable communication between a primary tubing string and the
wellbore in response to a second, higher, threshold pressure may be
used.
[0044] Referring to FIG. 10, another embodiment of a tool 110 is
generally shown. Similar to the tool 10 of FIGS. 1-9, the tool 110
is for releasably coupling a coiled tubing string to a primary
tubing string. The tool 110 includes a fitting 112, which is
located at an upstream end, a tool body 116, which is located at a
downstream end of the tool 110 and a transition member 114, which
is located between the fitting 112 and the tool body 116.
[0045] Referring to FIG. 11, the fitting 112 includes a channel 118
that receives a piston 120. The piston 120 is slidable relative to
an inner surface 122 of the channel 118 when shear pins 115, which
couple the piston 120 to a wall 132 of the fitting 112, fail.
Movement of the piston 120 through the channel 118 toward an
upstream end 122 of the fitting 112 is limited by an inwardly
extending flange 124, which functions as an upstream stop. Movement
of the piston 120 toward a downstream end 126 of the fitting 112 is
limited by an end surface 128 of the transition member 114, which
functions as a downstream stop.
[0046] A plurality of slots 130 extend through the wall 132 of the
fitting 112. The slots 130 are closed when the piston 120 is in an
upstream position in which the piston 120 abuts the inwardly
extending flange 124 to block communication between the channel 118
and the well. The slots 130 are open when the piston 120 is in a
downstream position in which the piston 120 abuts the end surface
128 of the transition member 114. In the present example, six slots
are provided in the wall 132 of the fitting 112. It will be
appreciated by a person skilled in the art that any number of slots
130 may be used as long as the flow area of the slots generally
equals the total open area of the primary tubing. Further, it will
be appreciated by a person skilled in the art that the slot
arrangement may be replaced with another wellbore access
mechanism.
[0047] A pressure line 134 extends through a first line fitting
136, which is received in the piston 120 and coupled thereto,
through the channel 118, through a second line fitting 138, which
is received in the transition member 114 and coupled thereto, and
through a bore 140 of the transition member 114 in order to
communicate with the tool body 116. The first line fitting 136
includes a pair of seals 142 and is slidable relative to the
pressure line 134.
[0048] Internal threads 144 are provided at the upstream end 122 of
the fitting 112 for mating with a threaded end of the primary
tubing string. Internal threads 146 are provided at the downstream
end 126 of the fitting 112 for mating with a threaded upstream end
148 of the transition member 114.
[0049] Referring back to FIG. 10, the transition member 114
includes a bore 150 for receiving an end joint 176. The bore 150
extends from an opening 152 in a side of the transition member 114
through the transition member 114 to a downstream opening 154. The
bore 150 is shaped to receive the end joint 176 of the coiled
tubing string 12 from a position outside of the tool 110 and feed
the end joint 176 into a coiled tubing-receiving channel 156 of the
tool body 116. The coiled tubing-receiving channel 156 is sized to
slidably receive the end joint 176 of the coiled tubing string 12,
which includes a cylindrical portion and an end portion, as has
been described with respect to the embodiment of FIGS. 1-9. The end
joint 176 of the coiled tubing string 12 may be pre-bent in order
to fit easily into the bore 150 during assembly of the tool
110.
[0050] As shown in FIG. 12, the tool body 116 is bullnose-shaped at
a downstream end 158 thereof to facilitate movement of the tool 110
through the wellbore when the primary tubing string is deployed.
The tool body 110 is coupled to the transition member 114 by bolts
160, which are received in mating bores 162 in an upstream end 164
of the tool body 116. The tool body 116 includes a first bore 166
and a second bore 168. The bores 166, 168 are located on either
side of coiled tubing-receiving channel 150. Plugs (not shown) are
received in upstream ends of the first and second bores 166, 168 to
seal the upstream ends of the bores 166, 168. Referring also to
FIG. 13, the first and second bores 166, 168 are sized to slidably
receive first and second pistons 170 and 172, respectively.
Downstream ends of the pistons 170, 172 extend through openings in
a wall 174 of the tool body 116 and seals are provided between the
wall 174 and the pistons 170, 172. The pressure line 134
communicates with the bores 166, 168.
[0051] The tool 110 includes a locking mechanism that is similar to
the locking mechanism of the embodiment of FIGS. 1-9; therefore,
like reference numerals have been used in FIGS. 12 and 13 to
identify components of the locking mechanism. The detailed
description of the components of the locking mechanism will not be
repeated here. Similar to FIGS. 1-9, other locking mechanisms
capable of selectively securing the coiled tubing end joint 176 to
the tool 110 may alternatively be used.
[0052] Referring to FIGS. 14 and 15, the end joint 176, which is
shown in FIG. 10, is coupled to the coiled tubing string 12 by a
rotating shear joint 182. The rotating shear joint 182 includes an
upstream body 184 that is received in an opening 190 of a
downstream body 186 and coupled thereto by shear pins 188. The
upstream body 184 includes a downstream end 194 including channels
196 formed therein and an upstream end 198 including channels 202
and grooves 200 formed therein. The downstream body 186 includes a
threaded downstream opening 192 for coupling to the end joint 176.
In order to couple the coiled tubing 12 and the end joint 176, the
upstream body 184 is inserted into the outer diameter of the coiled
tubing 12 and the coiled tubing 12 is deformed to conform to the
shape of the upstream body 184 and form a solid connection
therewith. The downstream body 186 is then threaded to threads of
the end joint 176.
[0053] The rotating shear joint 182 allows for rotation of the
coiled tubing string 12 relative to the end joint 176. Because the
rotating shear joint 182 is assembled using shear pins 188, if for
any reason, the coiled tubing cannot be retracted from the tool
110, the connection between the upstream body 184 and the downsteam
body 186 of the rotating shear joint 182 may be sheared and the
coiled tubing 12 retracted. In one example, six shear pins 188,
which have a maximum combined rating of 10000 lbs, couple the
upstream body 184 and the downsteam body 186 to one another. In
this example, pulling the coiled tubing 12 with a force that
exceeds 10000 lbs will cause the shear pins 188 to shear so that
the coiled tubing 12 may be retracted. The rotating shear joint 182
may also be used in place of the welded joint of the embodiment of
FIGS. 1-9.
[0054] In operation, after the coiled tubing string 12 has been
secured to the primary tubing string 14 by the tool 110, the
primary tubing string is fed down a wellbore. When an installation
location has been reached, fluid, such as water, for example, is
pumped through the primary tubing string. The fluid enters an
upstream end of the channel 118 of the fitting 112 and the pressure
line 134. Fluid from the pressure line 134 is forced through
openings into the bores 166, 168 and pressure within the bores 166,
168 increases. When the pressure in the bores 166, 168 reaches a
first threshold, the pistons 170, 172 are actuated to pivot the
cams 84, 86 to an unlocked position in which the cams 84, 86 no
longer engage the coiled tubing end joint. The coiled tubing string
12 and end joint 176 may then be retracted from the tool 110. Fluid
continues to be pumped into the primary tubing string and when the
pressure within the fitting 112 reaches a second threshold, the
shear pins 115 fail and the piston 120 slides into a downstream
position to open the slots 130, which opens communication between
the primary tubing string and the wellbore. The primary tubing
string and the coiled tubing string 12 are then ready for use.
[0055] The tool 110 is a low-profile tool that includes an overall
outer diameter that is less than an outer diameter of couplings of
the primary tubing string. In one example, the primary tubing
string has a diameter of 27/8 inches with couplings having an outer
diameter of 31/2 inches. In this example, the overall outer
diameter of the tool 110 is less than 31/2 inches. As will be
understood by a person skilled in the art, depending on the
diameter of the primary tubing string, the fitting 112 of the tool
110 is interchanged with other fittings 112 in order to match the
flow area of the slots with the total open area of the primary
tubing.
[0056] The tool 10, 110 facilitates downhole installation of coiled
tubing strings by coupling a coiled tubing string to a primary
tubing string. The tool 10, 110 has a low profile so that
modifications to the wellbore are not required to accommodate the
tool 10, 110.
[0057] In an embodiment, the pistons are fitted with snap rings in
order to restrict reverse movement of the pistons after they have
been actuated. The snap rings provide a fail safe arrangement so
that in the event that the fluid pressure is not able to maintain
the pistons in the actuated position, the snap rings are able to
perform this function.
[0058] In another embodiment, clamps are included to couple the
coiled tubing 12 to the primary tubing string 10 along the length
of the primary tubing string 10. Referring to FIG. 16. a first
clamp 204 is coupled to an upstream end of a coupler 206 and a
second clamp 208 is coupled to a downstream end of the coupler 206.
The coupler 206 joins adjacent primary tubing string members in
order to form the primary tubing string 10. As shown in FIGS. 17A
and 17B, the coupling 206 includes upstream and downstream threaded
inside surfaces 210 and 212, respectively, for receiving adjacent
primary tubing string members. Axial projections 214 extend from
opposite ends of the coupling 206. In the embodiment shown, five
axial projections 214 extend from each end. The axial projections
214 include openings 216 that extend circumferentially
therethrough.
[0059] Referring also to FIGS. 18A and 18B, the first clamp 204
includes a first clamp member 218 and a second clamp member 220
including a hinge 222 and a bracket 224 that is opposite the hinge
222. The hinge 222 includes hinge fingers 226 and 228 of the second
clamp member 220 that are coupled to hinge finger 230 by a pin 232.
The first and second clamp members 218 and 220 include cutouts 234
for receiving the axial projections 214 of the coupler 206.
[0060] The bracket 224 includes a first side member 236 and a
second side member 238. The side members 236, 238 include outwardly
extending arms 240 for retaining the coiled tubing 12 and
projections 242 that abut one another generally at a centreline of
the first clamp 204. Openings 246 extend through the projection 242
of the first side member 236 and are aligned with openings 248 that
extend partially through the projection 242 of the second side
member 238. The openings 246, 248 receive fasteners 250, which
secure the first clamp member 218 and the second clamp member 220
to one another. Openings 252 extend through the first side member
236 and the second side member 238 and are aligned with one another
to receive a fastener 254 that passes through the opening 216 of
the axial projection 214 of the coupler 206 that is sandwiched
between the first side member 236 and the second side member
238.
[0061] Referring back to FIG. 16, the second clamp 208 is generally
identical to the first clamp 204 but is installed in an opposite
orientation relative thereto such that the cutouts 234 are directed
toward the coupler 206 from both ends thereof. Together, the clamps
204, 208 limit non-axial movement of the coiled tubing string 12
relative to the primary tubing string 10. Some axial movement is
possible, however.
[0062] Referring also to FIG. 19, an end joint 256 for use with the
clamps 204, 208 is generally shown. The end joint 256 is similar to
the end joint 176 but rather than being bent, the end joint 256
includes hinges 258, 260 at the transition locations. Unlike the
fixed bends of end joint 176, the hinges 258, 260 allow the end
joint 256 to straighten in order to be retracted through the clamps
204, 208.
[0063] Although the example of FIGS. 16-18B shows a pair of clamps
for coupling the coiled tubing string 12 to the primary tubing
string 10, a single clamp may instead be used. Further, clamps need
not be provided at every coupler location on the primary tubing
string 10. One or more clamps 204, 208 may be provided at all of
the primary tubing member joints of the primary tubing string or at
some of the joints thereof.
[0064] The clamps 204, 208 described herein couple the coiled
tubing string 12 to the primary tubing string 10 along a length
thereof rather than at a single location (ie. at the tool 10, 110).
This arrangement avoids installations in which the coiled tubing
string 12 becomes wrapped around the primary tubing string 10 in a
helical manner, which leads to difficulties extracting the coiled
tubing string 12 without damage occurring thereto.
[0065] Specific embodiments have been shown and described herein.
Modifications and variations may occur to those skilled in the art.
All such modifications and variations are believed to be within the
scope and sphere of the present invention.
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