Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This is a division of copending Canadian patent
application Serial No. 312,675 which was filed on
October 4, 1978.
Background of ~he Invention
1. Field of the Invention~
The present invention pertains to apparatus for
operating on wells, such as in workover operations~ More
particularly, the present invention relates to coiled
tubing systems for injecting and extracting continuous
tubing into and out of wells in various well servicing
operations.
2. Description of Prior Art.
Coiled tubing systems for working on wells are
generally known. In such systems, a continuous metal
tubing is driven down tile well by way of an injector
head. A pair of continuous-chain tube grippiny dog
assemblies are motor driven in the injector head to grip
the tubing and move it down the well. Reverse operation
of the chain dog assembly is used to withdraw the tubing
from the well. On the surface, the tubing is stored on a
large drum or reel from which the tubing is withdrawn by
the pull of the injector head. The reel is motor driven
to rewind the tubing as it is withdrawn from the well.
The injector head is usually positioned on a mast over
the Christmas tree of the well. A pair of hydraulic
cylinder assemblies is used to vary the elevation of the
injector head along the mast to accommodate the height of
the Christmas tree as well as a blowout preventer added to
the well for the coiled tubing workover operation.
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While the entire coiled tubing system may be assembled
in place at the well, mobile systems are available. In
the latter case, the mast is mounted, for example, at the
back of a truck bed with the reel positioned toward the
opposite end of the bed. For transportation purposes the
mast is folded or pivoted toward a generally horizontal
position. When this is done, the injector head is also
tilted with the mast. Since the injector head is not
rigidly mounted on the mast, thereby allowing some lateral
movement of the head relative to the mast, such a tilting
operation involving the injector head is inherently
dangerous. Furthermore, prior art systems with foldable
masts are so designed that the injector head may not be
lowered to the level of the truck bed.
A level wind tubing guide mechanism provided for
guiding the tubing onto and off of the reel generally
extends, in its operating position, to a height in excess
of any desired road clearance value. Consequently, the
level wind guide assembly must be tilted backwardly
against the reel, for example, to permit highway
transportation of the system.
The tilting of the injector head as well as the level
wind guide mechanism in a transportation configuration
necessitates the disengagement of the tubing from the
injector head and its complete winding on the reel.
Conseyuently, ln such prior art mobile coiled tubing
systems, the tubing must be connected through the in]ector
head each time the system is to be used on a diEferent
well, and must be removed from the injector head and the
level wind guide assembly each time the system is to be
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moved. Also, since the injector head is pivoted with the
mast, the head is generally not available for servicing at
a low elevation yet in an upright configuration.
Furthermore current versions of coiled tubing assemblies
generally provide only elevational as well as forward and
backward adjustments for positioning the injector head;
the truck must be generally maneuvered to effect any
substantial sideways position adjustment for the injector
head.
Even in the case of mobile coiled tubing systems known
in the art, the blowou-t preventer used in such well
working operations must be moved into position separately
from the coiled tubing system. This often requires
manhandling the blowout preventer.
SUMMARY OF THE INVENTION
.
In accordance with an aspect of the invention there i5
provided apparatus for operating on wells comprising:
injector means for propelling tubing into or out of a
; well; carriage means for supporting said injector means;
and positioning means for selectively moving said injector
means generally transversely relative to the direction of
said well from said injector means~
The present invention provides coiled tubing apparatus
including an injector head mounted Eor selective elevation
on a foldable mast wherein the injector head is able to be
lowered to an elevation below the pivot point of the
mast. Consequently, the injector head remains in an
upright configuration as the mast is folded about its
pivot point.
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The mounting of the injector head on the mast provides
an increased degree of flexibility in laterally
positioning the injector head relative to the well. A
chain drive assembly is selectively operable to move the
injector head forward or backward relative to the mast. A
fluid pressure cylinder assembly is provided for a
left-right adjustment of the injector head. Consequently,
the injector head may be positioned by selective movement
along any one or more of three mutually orthogonal
directions, inclùding elevation along the mast.
A tubing reel is fitted with a level wind assembly
which features a height adjustment which retains the
assembly guide mechanism in an operative configuration
regardless of the height settingO Consequently, the
tubing may remain engaged by the level wind mechanism as
well as the injector head even though the mast is folded.
The present invention also provides a track and
carriage system for maneuvering a blowout preventer
between a storage position generally toward the tubing
reel and a forward position from which the blowout
preventer may be supported by the injector head for
positioning over the Chris-tmas tree of the well.
The present invention ~ontemplates coiled tubing
apparatus whose improved features are particularly
advantageous for a mobile system. Such a system may, for
example, be mounted on a f]atbed of a trailer truck, a
single-unit carrier, or a barge. In any event, individual
units such as the tubing reel, a power assembly including
motors and compressors, and a control houslng, may be
mounted on skids and placed on the bed of the
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transportation means~ In such cases, the mast and
injector head are then mounted at one end of the flatbed
for positioning at the wellO The skids may be held
against lateral movement relative to the flatbed by
pinning the skids to the bed.
The present invention provides a coiled tubing system
which may be rapidly placed in an operative configuration
upon arrival at a well since the tubing may be retained
engaged within the level wind guide assembly as well as
the injector head during transportationO Similarly, the
system is ready for transportation relatively quickly
since the tubing need not be completely rewound on the
reel. Further, the provision for handling the blowout
preventer along its track and carriage system as well as
picking up the blowout preventer by the injector head
directly from the flatbed provides a faster, easier, and
safer means for manipulating the blowout preventer onto
and off of the well Christmas tree. The present invention
also provides increased flexibility in maneuvering the
injector head into position over the well.
A significant advantage of the present invention over
the prior art lies in the ability to lower the injector
head below the pivot point of the mast so that the mast
may be folded without having the injector head supported
by the tilted portion of the mast. The injector head
alwa~s remains upright, and the folding of the mast is
safer. Furthermore, the ability to lower the injector
head to the bed of the transportation mechanism provides
greater access for servicing the injector head as well as
allowing easier and safer initial mounting of the injector
head on the mast.
BRIEF DESCRIPTION OF THE DRA~INGS
The present invention taken in conjunction with the
invention disclosed in copending Canadian patent
application Serial No. 312,675 which was filed on
October 24, 1978, will be described in detall hereinbelow
with the aid of the accompanying drawings, in which:
Fig. 1 is a side elevation of a coiled tubing system
of the present invention with the mast folded;
Fig. 2 is a view similar to Fig. 1, but the mast erect;
Fig. 3 is an enlarged side elevation of the mast and
injector head;
Fig. 4 is a view similar to Fig. 3, showing the
injector head elevated along the mast;
Fig. 5 is an end elevational view along the line 5-5
of Fig. 41 partially broken away;
Fig. 6 is a cross-sectional view of the injector head
framing and carriage structure along line 6-6 in Fig. 5,
but with details of the injector head removed for clarity;
Fig. 7 is a cross-sectional view taken along line 7-7
of Fig. 6;
Fig. 8 is a cross-sectional view taken along line 8-8
of Fig. 6;
Fig. 9 is a cross-sectional view taken along line 9-9
of Fig. 1, illustrating the blowout preventer carriage and
track system;
Fig. 10 is a fragmentary view o the mast pivot
mechanism;
Fig. 11 is a fragmentary viewl in cross section, o~
the level wind mechanism illustrating the height variation
capabi]ity; and
SO
Fig. 12 is a fragmentary exploded view in perspective
illustrating the manner of pinning equipment skids to the truck
bed.
Description of Preferred Embodiments
Coiled tubing apparatus according to the present
invention is shown generally at 10 in Figs. 1 and 2, mounted
on the flatbed 12 of a trailer truck 14. While the improved
system of the present invention may be utilized in stationery
as well as mobile assemblies, and such mobile arrangements
may take several forms including barge mounts or unitized~
carrier mounts, a trailer arrangement is shown and discussed;
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herein by way of illustration rather than limitation.
The flatbed 12 supports a tubing reel assembly 16
mounted on a skid 18, a power unit 20 mounted on a skid 22, ;~
~; and a control house 24 mounted on a skid 26. The control
house 24 includesmost or all of the controls necessary for
operating the various hydraulic and pneumatic systems employed
with the coiled tubing~apparatus, and is otherwise conventional.
The power unit 20 includes the necessary power means used in
operating the coiled tubing apparatus, including motors,
a pneumatic compressor, and a hydraulic pump.
Both the power unit skid 22 and the control house
skid 26 are anchor~ed against lateral movement along the flat-
bed 12 by hold down pins 28 shown in more detail in Fig. 12~
The frame of the power `skid 22, for example, is e~uipped with
at leask one sleeve 30 of rectangular cross section on each
side of the skid. The ends of each sleeve 30 are open through
holes provided in the skid frame. The skid 22 is positioned
on the flatbed 12 so that the sleeve 30 is aligned with a
bracket 32 providing a passageway comparable in cross section
to that of the sleeve. The pin 28 is inserted through the
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top of the sleeve 30 to protrude below -the bottom of the
bracket 32. A laterally extending lip 28a prevents the pin
28 from passing completely through the skid frame. A keeper
pin 34 is inserted through a hole 28b in that portion of the
pin 28 which extends below the bracket 32 to prevent in-
advertent removal of the pin from the sleeve 30. With at
least one such pin 28 provided on each side of skids 22 and
26, the power unit and control house are held securely in
place against lateral movement along the flatbed 12. A
similar hold down pin arrangement may be provided for the
tube reel skid 18, or this skid may be secured by other
appropriate means such as chaining or bolting the s~id to
the flatbed (not shown).
Tubing 36 used in the well working operation is
stored on the reel 16 and is fed through a level wind guide
38 to an injector head 40. The injector head 40 is mounted
on a mast shown generally at 4~. The mast 42 is mounted on
the flatbed 12 by bolting and/or welding.
Details of the mast construction may be appreciated
by reference to Figs. 1-5 and 10. The mast 42 includes a
pair of upper mast legs 44 and 46 pivotally mounted on lower
mast legs 48 and 50, respectively. The lower mast legs 48
and 50 are each fixed to the flatbed and further braced
thereto by beams 52 and 54. Mast components 44 through 54
are generally of I-beam constructlon. An assembly of cross-
beams 56 joins the tops of -the upper mast legs 44 ~nd 46 and
ensures a rigid, stable mast construction.
The manner of pivotally joining the upper mast
legs with the respective lower mast legs may be appreciated
by reference to Fig. 10. A hinge assembly is constructed to
include an upper hinge plate 58 fixed to the bottom of the
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upper mast leg 44 and a lower hinge plate 60 fixed to the top
of the lower mast leg 48. Bracing 62 and 64 is provided for
the upper and lower hinge plates, respectively. The two
hinge plates 58 and 60 are joined by a hinge pin 66 about
which the upper mast leg 44 pi~ots relative to the lower
mast leg 480 A similar hinge assembly is provided whereby
the upper mast leg 46 pivots relative to the lower mast leg
50, with the hinge pins of both hinge assemblies generally
possessing a common rotational axis. This axis about which
the upper mast section pivots is laterally displaced a short
distance from the vertical projection of the lower mast legs
48 and 50O However, with the upper mast section erect, the
upper mast legs 44 and 46 are placed generally directly above
the lowex mast legs 48 and 50, respectively, and func~ion as
continuations thereoi
The manner in which the mast pivots may be best
appreciated by reference to Figs. l and 2. A pair of fluid
pressure piston-cylinder assemblies 68 (only one visible)
joins the upper mast legs 4~ and 46 to the lower mast leg
braces 52 and 54, respectively. Thus, the cylinders 68 are
effectively anchored to the flatbed 12. As the pistons are
retracted in the cylinder assemblies 68, the upper mast
section, including the upper mast legs 44 and 46, is lowered
to an essentially horizontal configuration as indicated in
Fig. l. In this posture, the upper mast section is supported
by the two hinge pins and by a pair of pads 24a located on
the top of the control house 24 for receiving the upper mast
legs 44 and 46. The pads 24a prevent the crossbeams 56
from contacting the roof of the control house 24, leaving
sufficient spacing between the house and these beams to
permit the tubing 36 to pass through as indicated in Fig. 1.
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As the piston rod of each cylinder 68 is extended
under the influence of applied fluid pressure, the upper mast
section pivots about the hinge pins as indicated by the arrow
in Fig. 2. Ultimately, the upright configuration of Figs.
2-5 is achieved wherein the upper mast legs 44 and 46 are
aligned with, and resting on, the lower mast legs 48 and 50,
respectively. With the upper and lower hinge plates 58 and
60 closed on each other in this upright mast configurationr
a pair of swing bolts and nuts are positioned and tightened
across the hinge plates o each of the two mast leg structures.
As illustrated in Figs. 5 and 10, each of the swing bolts 70
is pivotally anchored, by means of a pin 72, to the respective
lower mast leg 48 or 50. The hinge plates 58 and 60 are
equipped with slots to receive the swing bolts 70. With the
bolts 70 thus positioned, associated nu~s 74 are tightened
~; against the upper hinge plates. The four swing bolts 70 and
nuts 74 thus anchor the upper mast legs 44 and 46 to the
corresponding lower mast legs 48 and 50, respectively, to
maintain the upper mas~ section in the erect configuration~
The in]ector head 40 is carried by a carriage -
structure shown generally at 76. Details of the carriage
structure may be more fully appreciated by reference to
Figs. 3-8. The carriage structure at 76 includes a hori-
~ontal carriage platform 78 and a vertical carrier assembly
80. The vertical carrier assembly 80 includes side panels
82 and 84 joined at the top by a crossmember 86 and at the
bottom by a beam construction 88. A pair of channel beams
90 and 92 ride within the mast legs 44, 48 and 46, 50,
respectively. The channel beams 90 and 92 are fixed on
the outer surfaces of the side panels 82 and 84, respectively,
and bear the left-right lateral load between the vertical
carrier assembly and the mast. A pair of rollers 94 are
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mounted on each of the side panels 82 and 84 just beyond the
upper and lower ends of each of the guides 90 and 92. The
rollers 94 bear the lateral load in the forward and backward
direction between the vertlcal carrier assembly and the
corresponding mast legs. The combination of the channel
beams 90 and 92 and the rollers 94 serve to guide the
vertical carrier assembly 80 along the mast legs.
The horizontal carriage platform 78 features a base
plate 96 and a pair of longitudinally extending side arms 98
and 100 whose cross sections resemble that of a channel beam.
A plate 102 connects the back end of the side arms 98 and 100,
and each of these arms is subtended at the front end by a
cover plate 104.
The side arms 98 and 100 ride between upper and lower
sets of rollers 106 and 108, respectively, mounted on the
interior of both side plates 82 and 84. Additionally, upper
and lower rails 110 and 112, respectively, are fixed to each
of the side panels 82 and 8~ to further constrain vertical
movement of the horizontal carriage platform relative to the
vertical carrier assembly.
Tubing injector heads such as the one indicated at
40 are well known in the art, and will not be described in
detail herein. It should be noted, however, that the basic
elements of such an injec-tor head, including the chain dog
assemblies, the motor and gear mechanisms and the chain
tensioner mechanism, may be mounted within a framework 11~.
Further framing including horizontal members 116 and memhers
118 provide additional support for mounting the various
injector head components. As best seen in Fig. 6, the
horizontal members 116 are joined ~y a support post 120 and
a pivot union 122 to a skid base 124. The skid base fits
within the area defined by the platform side arms 98 and 100
the back plate 102, and the cover plates 104 of the horizontal
carriage. As may be appreciated from Figs. 6-8, the skid base
124 is inserted within the side arms 98 and 100 before the
end plates 104 are bolted into position. Further, the skid
base 124 is capable of a modexate amount of lateral movement
relative to the horiæontal carriage platform in forward and
backward as well as sideways directions.
A bracket 126 extends upwardly from a front cross
bar 124a of the skid base and is coupled to the piston rod
of a fluid pressure piston-cylinder assembly 128 whose cylinder
is fixed by a bracket 130 to the side arm 100 of the hori-
zontal carriage platform. Operation of the piston-cylinder
assembly 128 by application of fluid pressure thereto causes
the skid base 124 to move to the right or left relative to
the horizontal carriage platform as the piston rod of the
cylinder is extended or retracted, respectively. ~n this
fashion, the injector head mounted on the skid base 124 is
provided à degree of freedom in a generally horizontal
direction transverse to the direction of folding of the mast
~2.
As illustrated in Figs. 6 and 7, the horizontal
carriage platform 7~, with the skid base 124 and the
injector head 40 mounted thereon, may be moved forward and
backward parallel to the direction of folding of the mast
42 by means of a chain drive assembly shown generally at
132. A pair of chains 134 is anchored to the bottom of
the horizontal carriage platform at points 136 and 138, and
pass around a pair of idler sprockets 140 and 142 and a drive
sprocket 144 between and below the idler sprockets. The
shaft of the drive sprocket is coupled at 146 to a worm
drive 148 which, in turn,is joined to a reversable motor 150.
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Operation of the motor in one rotational sense or the othercauses the drive sprocket 144 to be driven through the worm
drive 14~ in one rotational sense or the other to move the
chain forward or backward, respectively, around the drive
sprocket and the idler sprockets 140 and 142. Consequently,
the horizontal carriage platform 78, and, therefore, the
injector head 40, are caused to move forward or backward in
response to such operation of the motor 150. In this fashion,
the injector head 40 is provided a degree of freedom in a
; 10 generally horizontal direction along the direction in which
the mast 42 is pivoted. Further, the use of the worm drive
148 provides a positive locking mechanism wherein the hori-
zontal carriage platform 78 is maintained in the relative
horizontal position in which it is located upon cessation of
operation of the motor 150. This is true because any tendency
for the horizontal carriage pla~form 78 to be moved without
operation of the motor 150 causes the chain to move through,
and rotate, the sprockets 140 through 144 with the result
that the worm drive 148 must also be turned. Since such
backward driving of the worm drive 148 through the coupling
146 is met with considerable resistance by the worm drive
itself, the horizontal carriage assembly 78 is positi~ely
locked into position without operation of the motor 150.
The mast at 42 is equipped with a double cylinder
pickup system including outer cylinders 152 and 154 and inner
cylinders 156 and 158, as best seen in Fig. 5. The tops of
the cylinders 152 through 158 are joined by a crossmember
160 which features wrap-around ends 160a which ride along the
I-beam flanges of the upper mast legs 44 and 46. The lower
ends of cylinders 152 and 156 are joined by an end plate
162 with a wrap-around extension 162a which also rides along
the I-beam construction of upper mast leg 44. Similarly,
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the bottom ends of the cylinders 15~ ancl 158 are joined byan end plate 164 with a wrap-around extension (not visible)
which rides along the I-beam construction of the upper mast
leg 46. The "gripping" of the members 160 through 164 of
the upper mast legs 44 and 46 serves to guide the cylinders
152 through 158 along the upper mast section and prevent any
separation of the cylinder system from the mast.
The outer cylinder assemblies 152 and 154 feature
upwardly directed piston rods 152a and 154a, respectively,
which are coupled to the top of the mast at brackets 166.
The inner cylinders 156 and 158 feature downwardly directed
piston rods 156a and 158a, respectively. These latter piston
rods 156a and 158a may be extended downwardly and connected
by pins to clevises 168 mounted on the side panels 82 and 84,
respectively, of the vertical carrler assembly 80. Then,
as the Eluid pressure is selectively applied to the cylinder
assemblies 152 through 158, the vertical carrier assembly
80 may be raised or lowered along the erect mast 42.
; Consequently, a third degree of motion is provided for the
injector head 40 in a vertical direction along the mast.
The outer channel of each of the I-beam mast legs
44 through 50 is fitted with a series of rods 170 which
function as ladder steps along -the mast. The rods 170 along
the upper mast legs 44 and 46 are for the most part of heavy
duty design, as indicated in Figs. 3 and 4 by their increased
thickness, and protrude beyond the front surfaces o~ the
upper mast legs in the form of studs with upset ends 170a.
As shown in Fiy. 5, a latch arm 172 is pivotally connected
by a bracket 174 and pln 176 to the side panel 82 of the
vertical carrier assembly 80. A wing 172a extends laterally
from the latch arm and is joined to a fluid pressure piston-
cylinder assembly 178 which is flexibly anchored to the side
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panel 82 by a bracket 180. As fluid pressure is appropriately
applied to the piston-cylinder 178, the piston rod may be
extended to swing the latch arm 172 over a stud 170a to there-
by anchor the vertical carrier 80, and the injector head 40
against downward movement relative to the mast 42. With the
piston of the cylinder assembly 178 contracted, the latch arm
172 is rotated clockwise, as viewed in Fig. 5, in an arc away
from the studs 170a. With the latch arm 172 thus disengaged
from the studs 170a, the vertical carrier assembly 80 may
be raised or lowered as desired by operation of the cylinder
assemblies 152 through 158. A similar pivoted latch arm,
operated by a piston-cylinder assembly, is indicated at 182
mounted on the other side panel 84 of the vertical carrier
assembly 80 to selectively engage or disengage studs 170a
along the other upper~mast leg 46. The two latch arms may
be operated simultaneously by linking the fluid pressure
lines leading to the corresponding piston-cylinder assemblies.
Thus, in addition to the plston-cylinder assemblies 152
through 158 maintaining the vertical carrier assembly~80 and
the injector head 40 at a selected elevation by appropriate
application of fluid pressure to these cylinders, the latch
arms are available for preventing downward movement of the
vertical carrier assembly and injector head in the event~of
a ~ailure in the cylinders 152 through 158, or in the flu1d
pressure lines leading thereto.
The lower mast legs 48 and 50 are joined together
below the flatbed 12 by a crossbeam assembly 184. Screw
jacks 186 carried at the base of each of the lower mast
legs 48 and 50 may be extended downwardly to engage the
ground prior to the elevation of the upper mast section.
Thus, with the coiled tubing assembly in position to operate -
on a well, a significant portion of the weight of the mast
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42 and the injector head 40 may be supported directly on
the ground through the screw jacks l~G.
An outrigger 188 is also carried by each of the
lower mast legs 48 and 50, and includes a leg 190 telescoped
within the outrigger sleeve and ending in a footpad 192. The
leg 190 may be extended and pinned to the outer sleeve so
that the footpad 192 may be placed firrnly on the ground with
the entire outrigger 188 oriented at an angle of, say, 45
relative to the vertical. The leg 190 is then secured at
this position by a chain or cable 194 leading to the base
of the associated lower mast leg. When the coiled tubing
assembly of the present invention is in a transportation
configuration as indicated in Fig. 1, with the mast folded,
the legs 190 are retracted and the outriggers 188 are
folded against the corresponding lower mast legs. Similarly,
the screw jacks 186 are retracted within the inner channels
of the lower mast leg I-beams.
A blowout preventer 196 is provided for use on the
Christmas tree of the well on which the coiled tubing assembly
is to operate. A pair of channel beams 200 (Fig. 9) are wel-
ded to the flatbed 12 between the position of the control
house 24 and the anchoring of the mast 42. These channel
beams 200 form a track system along which a blowout preventer
carriage 202 may ride on rollers 204. The blowout preventer
196 may be carried on the carriage 202 and fastenecl there by
any appropri.ate means, such as, for example, set-ting the
blowout preventer on an upright stud 202a provided on the
carriaye for that purpose. For transportation and storage
purposes the blowout preventer carriage 202, with the blowout
preventer 196 positioned thereon, is moved towarcd the
control house 24. In this position, the blowout preventer
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196 does not interfere with the lowering of the injectorhead ~0 so that the mast 42 may be folded, as indicated in
Fig. 1. With the mast 42 erect and the injector head 40
elPvated, the blowout preventer may be moved forward by
advancing the carriage 202 along the track system of the
channel beams 200 until the blowout preventer is positioned
generally under the elevated injector head. A cable or
chain 206 may be used to join the blowout preventer to the
bottom of the skid base 124 as indicated in Fig. 4. The
blowout preventer 196 may then be swung forward until it is
in position over the Chxistmas tree of the well, (not shown),
as indicated by the phantom lines in Fig. 4. In this
fashion, the combination of the vertical carrier assembly 80
and the horizontal carriage platform 78, both supported on
the mast 42, serves as a crane to allow the blowout preventer
196 to be swung into position over the well from the flatbed
12. When the well operation is completed, the cable or
chain 206 may be used to reconnect the blowout preventer 196
to the skid base 124 to allow the blowout preventer to be
swung back onto the carriage 202 for ultimate movement back
into the storage or transportation configuration toward the
control house 24, as indicated in Fig. 1.
The skid base 124 is fitted with a tube straightener
208 i.llustrated in detail in Fig. 6. The tube straightener
208 includes a pipe guide composed of three free wheeling
rollers 210, 212, and 214 arranged in a plane with parallel
rotational axes, as indicated in Fig. 6. The tubing 36 is
received by the injector head 40 and passed along the chain
dogs (not shown in detail) and down through the tube
straightener 208. I~ithin the tube straightener 208, the
tubing 36 passes on the forward side of the rear wheels 210
and 214, and to the rearward side of the front wheel 212.
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The forward-backward lateral displacement of the forward
wheel 212 relative to the other two wheels 210 and 214 is
such that the tubing 36 is given a slight forward concave
curvature to compensate for the opposite curvature enforced
therein by passage through the injector head 40. Consequently,
the tubing 36 emerging from the bottom of the tube straightener
208 is essentially straight.
A tubing meter 216 is provided at the vicinity of
the tube straightener 208 to measure the length of tubing 36
injected into, or extracted from, the well being worked. It
i~ particularly advantageous to place the tubing meter 216
between the injector head 40 and the well so that whatever
stretching may have been effected on the tubing as it was
driven downwardly by the injector head 40 will have occurred
prior to the measurement of the tubing length. Consequently,
a relatively more accurate reading of the amount of tubing
36 actually injected into the well may be obtained.
The level wind tubing guide 38 fitted on the coiled
tubing reel 16 is shown in some detail in Fig. 11. Vertical
framing 218 supports a pair of end plates 220 (only one shown).
A pair of lower rails 222, constructed of tubing of square
cross-section and extending between the end plates 220, is
joined by spacers 224 to matchlng upper rails 226 also
extending between the end plates. A multi-return cylinder
228 is supported at the end plates 220 by appropriate bearing
assemblies tnot shown). A guide carriage 230, e~uipped with
a floating nut 232 encompassing the cylinder 228, is constrained
to lateral movement by bearings 234 mounted on the carriage
and riding between the rails 222 and 226. Extending from the
carriage 230 is a pair of sleeves 236 (only one visible).
Each of the sleeves 236 receives a leg 240 which is slidable
within the corresponding sleeve as indicated by the arrow.
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The legs 240 may be set at a desired height by pinning thelegs to the respective sleeves 236 through holes 240a in the
legs aligned with holes 236a in the sleeves. The tubing
guide 38 is fixed to the top end of the legs 2~0 and moves
up and down with the legs as the latter are moved along the
sleeves 236. Thus, the guide 38 may be positioned at a
variety of heights as desired for convenience of operation,
as illustrated in Fig. 2, or lower to achieve a low profile
for road clearance, as shown in Fig. 1. The guide 38 is
of standard design including rollers 38a against which the
tubing 36 may bear in the vertical direction as well as
additional rollers (not visible) against which the tubing
may bear in the transverse direction.
The tubing reel assembly 16 is equipped with a
motor drive and appropriate gear or chain linkages (not
shown) in a conventional manner. Thus, the motor of the
reel assernbly 16 may be selectively operated to rotate the
reel to take up the tubing 36 as it is extracted from the
well. Additionally, a drag effect may be produced by
operating the motor of the reel assembly 16 to resist the
unwinding of the tubing 36 from the reel as the tubing is
being injected into the well. This drag-producing
operation may be used to maintain a desired amount of
tension in the tubing between the reel and the injector
head ~0 as well as to prevent the reel from running free
and unwinding the tubing at a rate greater than desired.
The motor of the reel assembly 16 is also connected
by appropriate belts or chains (not shown) to the multi~
return cylinder 228 to rotate this cylinder whenever the
reel itself is being rotated. Thus, when the reel, for
example, is being rotated to take up the tubing 36, the
cylinder 228 is continuously rotated in one rotational
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5~
sense thereby causing back and forth lateral motion of the
~ carriage 230 due to the meshing of the floating nut 232mounted thereon with the helical grooves of the cylinder.
As the carriage is thus swept back and forth, the tubing
guide 38 is also maneuvered back and forth relative to the
reel and guides the tubing 36 accordingly. Thus, in a well
known manner, the tubing 36 is wound in a level fashion on
the reel 16. When the tubing 36 is being removed from the
reel, rotation of the reel is accompanied by rotation of the
multi-return cylinder 228 due to the linkage of the cylinder
to the motor, and to the reel 16. ~onsequently, the carriage
~30 and the tubing guide 38 are again swept back and forth
across the face of the reel 16 to facilitate the removal
of the tubing therefrom.
The reel assembly 16 is fitted with a fluid-seal
swivel device 242 incorporated in the hub of the reel in
a well known manner. With one end of the tubing 36 extending
down the well, the opposite end of the tubing fixed relative
to the reel drum may be secured to one end of the swivel
device 242 which rotates with the reel. Then, with the
tubing 36 in the well, fluids of various kinds may be
introduced down the well through the tubing 36 by means of
the swivel device 242.
The fluid pressure lines from the power unit 20
and the control house to the reel drive motor and the
various fluid pressure devices on the mast 42 and injector
head 40 have not been expressly included in the drawings
for purposes of clarity. Such fluid pressure communication
lines are generally conventional. However, the fluid
pressure lines used in the present system may be fitted with
counterbalance valves. Such counterbalance valves are known,
but not heretofore employed in coiled tubing systems. The
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5i~
counterbalance valves function to prevent rapid loss inpressure in a cylinder when a leak or break has occurred in
the associated pressure line. Thus, a safety factor is added
to prevent, say, dropping of the injector head, or collapsing
of the mas-t, when such a leak or break occurs.
When the coiled tubing assembly as described
herein is brought to a well to be worked, it may be generally
in the configuration illustrated in Fig. 1. Thus, the injec-
tor head 40 is in its lowermost position with the mast folded.
The tubing 36 may or may not be extended through the guide
38 and the injector head 40 to the tube straightener 208. In
either case, the tubing guide 38 would most likely be in a
retracted configuration as shown to provide necessary road
clearance for transporation.
The truck 14 is maneuvered to back the flatbed 12
to the vicinity of the well. The outriggers 188 are positioned
as described hereinbefore and the screw jacks 186 are lowered
against the yround. With the engine of the power unit 20
operating, the hydraulic pump and pneumatic compressor are
operable. The air compressor is generally utilized to
operate the chain tensioner tnot shown) which is part of
the injector head.
~ Iydraulic pressure is applied to the cylinder
assemblies 68 to raise the mast to its vertical operating
configuration. The four swing bolts 70 are positioned and
locked. The double cylinder pickup system is then lowered
by extension of the outer piston rods 152a and 154a, and
the two inner piston rods 156a and 158a are lowered and
pinned to the clevises 168 of the vertical carrier assembly
80. The cylinders 152 through 158 are further operated to
elevate the injector head 40 along the mast 42.
The blowout preventer 196 is then moved forward
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L9~50
on its carriage 202 to a position under the elevated injector
head 40 as indicated in Fig. 4. The cable or chain 2Q6 is
used to connect the blowout preventer 196 to the injector
head skid base 124 and the vertical carrier assembly 80 is
further elevated. With the blowout preventer suspended from
the skid base 124, the blowout preventer carriage 202 is
returned to its transportation position toward the control
house 24. The chain drive 132 is then operated to move the
injector head 40 forward until the tubing straightener 208
is directly over the well. If necessary, the left-right
adjustment cylinder 128 may be operated to move the front
end of the skid base 124 and, therefore, the injector head
40 and the associated tubing straightener 208 laterally to
position the tubing straightener over the well. The blowout
preventer 196 is fastened to the top of the well Christmas
tree and disengaged from the skid base 124.
The level of the injector head may again be adjusted,
if necessary. When finally set at the desired operating
position, the vertical carrier assembly is secured to the
mast by the latch arms 172 engaging the studs 170a.
The level wind tubing guide 38 is raised to a more
convenient operating position as indicated in Fig. 2, and the
tubing 36 is advanced by operation of the injector head 40
through the tube straightener 208 down through the blowout
preventer 196 into the well. IE necessary, the tubing is
first extended from the reel 16 through the tubing guide 38
and the injector head 40 to the tubing straightener 208.
Continued operation of the iniector head 40
Eorces more of the tubing down the well. During this
pxocedure, the tubing meter 216 maintains a constant reading
on the amount of tubing 36 that has been iniected into the
well. Also, the motor of the reel assembly 16 may be so
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3195al
operated as to properly tension the tubing leading into theinjector head 40.
When the tubing end is positioned at the desired
level in the well, necessary operations may be carried out
through the tubing 36 by means of the swivel device 242.
For example, liquids may be introduced into the well through
the tubing 36 to pump mud or sand from the well. Also,
pressurized gasses such ~s nitrogen may be injected into the
well in the workover operation.
When the workover operation has been completed, the
injector head 40 may be operated in the opposite direction to
extract the tubing 36 from the well as the reel 16 is rotated
by its own drive motor to take up the tubing onto the reel.
Once the tubing 36 is clear of the blowout preventer 196, it
need not be completely wound on the reel, but may be left
extending through the injector head 40 and the tube straightener
208. At that point, the blowou~ preven~er 196 may be again
connected to the skid base 124 by the cable or chain 206 and
:: ,
raised off of the Christmas tree. The chain drive assembly
132 and, if necessary, the left-right adjustment cylinder
128 are operated to return the horizontal carriage assembly '! `.
78 and the injector head 40, with ~he blowout preventer L96
suspended therefrom, to the original lateral position
indicated generally in Fig. 4. The carriage 202 is moved
under the injector 40 and the blowout preventer 196 is
positioned on the carriage and disconnected ~rom the skid
base 124. The blowout preventer and its carriage are then
returned to their transportation position. The latch arms
172 are disengaged ~rom the studs 170a and the vertical
carrier assembly 80 is lowered to the ~latbed 12 as shown
in Fig. 3.
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, ~
513
The inner piston rods 156a and 158a are disengaged
from the clevis connectors 168 and the four piston rods 152a
through 158a are contracted to return the four cylinders 152
through 158 to the top of the mast as indicated in FigO 2.
The four swlng bolts 70 are loosened and swung free of the
upper hinge pla-tes 58 and the cylinders 68 are operated to
lower the mast to its transportation configuration as
indicated in Fig. 1.
The tubing guide 38 is lowered by allowing the legs
240 to pass through the sleeves 236 to a lower position, with
the tubing 36 still passing through the guide 38 to the injec-
tor head 40 and the tubing straightener 208. The screw jacks
186 are raised into the lower mast legs 44 and 46, and the
outriggers collapsed and returned to their travel positions
against the lower mast legs as well. The coiled tubing
assembly of the present invention is then ready to be moved
to the next well working operation.
It will be appreciated that the present invention
provides a coiled tubing apparatus that is relatively convenient
and safe to use in well working operations. The capability of
lowering the injector head to the flatbed, particularly in
an upright configuration, provides increased access for
servicing the injector head in a safer and more convenient
manner. Furthermore, the ability to fold the mast for
tr~nsportation purposes without the great weight of the
injector head and the associated carriage structure being
suspended on the pivoted portion of the mast makes folding
the mast and transporting -the apparatus safer procedures.
The chain drive assembly for lateral movement of the
injector head horizontal carriage platform, including the
worm drive locking mechanism, allows the injector head to
be moved forward and backward with relative ease. Fur-ther,
- 24 -
11199S~D
theleft-right adjustment cylinder enchances the degree of
flexibility of movement of the injector head over the wall.
The blowout preventer carriage and track system further allow
operations associated with the workover of wells to be carried
out with greater ease and safety since the blowout preventer
may now be moved along the flatbed and suspended from the
elevated injector head to be positioned over the Christmas
tree with little or no manhandling. Also, the height
adjustment of the level wind tubing guide allows the tubing !~
guide to be lowered for road clearance purposes while retain-
ing the tubing intact therein and extended through to the
injector head. Thus, less time is required in setting up
the coiled tubing apparatus for workover operations as well :;
: as in placing the apparatus in condition for transporting on
a highway.
The foregoing disclosure and description of the
invention is illustrative and explanatory thereof, and
~: various changes in the size, shape and materials, as well
as in the details of the lllustrated construction may be :;
: 20 made within the scope of the appended claims without
departing from the spirit of the invention.
. ;:
.
~ 25 ~ :
