Note: Descriptions are shown in the official language in which they were submitted.
CA 02871825 2015-01-29
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INJECTOR HEAD CHAIN SYNCHRONIZATION DEVICE
FIELD OF THE INVENTION
The present invention relates to a conveyor apparatus or injector head to
enable feeding of continuous elongate device (CED), such as e.g. coiled
tubing, rod, wire or wireline down through the conveyor apparatus, to enable
insertion of tools through the wellhead and into a well below, or up through
the
conveyor apparatus by pulling action enabling retrieval of such tools from the
to wellhead and the well below. In particular the invention relates to an
injector
head with synchronized belt drive chains.
Such a conveyor apparatus is frequently called an "injector head" in this
particular field of use
The wellhead is primarily used for oil and natural gas exploration and
production operations.
Particularly, the present invention relates to a technology for inserting and
retrieval of a drill tool being supported by continuous elongate device (CED)
in
a non-limiting example being e.g. a continuous tubing, suitably coiled tubing
running through the lubricator string sections.
In the description and claims, the general term CED, i.e. Continuous Elongate
Device, will be used, implying that the CED may be interpreted as being a
continuous tubing (e.g. coiled tubing), continuous rod or interconnected rod
sections, continuous wire or continuous wireline. In case of rods or rod
sections, this could e.g. be massive rods of metal, metal alloys, carbon
material, fiber reinforced plastic material.
The continuous elongate device will hereinafter be referred to as a continuous
tubing.
More particularly the present invention relates to an injector head according
to
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the preamble of claim 1.
TECHNICAL BACKGROUND OF THE INVENTION
Use of CED's, such as e.g. coiled tubing, sourced from a hydraulically
operated
reel is known in oil and natural gas exploration and production operations.
These tubings, generally refer to metal pipes, e.g. made from steel, with
diameter ranging between 1 inch and 4 inches (2.54 - 10.12 centimeters), or
suitably within the range 1.5 to 3.5 inches (3.81 - 8.89 centimeters). Such
tubing
to may typically have a wall thickness of 5 -15% of the tubing diameter,
although a
different wall thickness range may applied dependent on the use of the tubing.
It is also known, that coiled tubing can perform many different oil well
operations, and these include use in interventions in oil and gas wells, and
use
as production tubing in gas wells as well.
Application of such coiled tubing in oil and gas operations involves deploying
the tubing as support for drill tools for inserting those tools into boreholes
or for
retrieving those tools from boreholes. Such tools can be packers, valves,
sleeves, sensors, plugs, gauges and so on, which have to be run into and
retrieved from the boreholes. These tools may find use for servicing the well.
The operations as stated in the preceding paragraph are done through
lubricator string sections and those sections serve as a sluice for
undertaking
such operations.
How a lubricator string functions for insertion of tools into the well and for
retrieval of the same therefrom, are all common knowledge in the art and will
not be elaborated any further.
When in use, a coiled tubing injector is normally mounted to an elevated
platform above a wellhead or is mounted directly on top of a wellhead. A
typically coiled tubing injector is comprised of two continuous belt drive
chains,
though more than two can be used. The belt drive chains are mounted on
sprockets to form elongated loops that counter rotate. A drive system applies
CA 02871825 2015-01-29
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)(
torque to the sprockets to cause them to rotate. In most injectors, belt drive
chains are arranged in opposing pairs, with the pipe being held between the
belt
drive chains. Grippers carried by each belt drive chain come together on
opposite sides of the tubing and are pressed against the tubing. The grippers,
when they are in position to engage the tubing, ride or roll along a skate,
which
is typically formed of a long, straight and rigid beam. The injector thereby
continuously grips a length of the tubing as it is being moved in and out of
the
well bore. Each skate forces grippers against the tubing with a force or
pressure
that is referred to as a normal force, as it is being applied normal to the
surface
to of the pipe.
A drive system for a coiled tubing injector includes at least one motor. For
larger
injectors, intended to carry heavy loads, each belt drive chain will typically
be
driven by a separate motor. The motors are typically hydraulic, but electric
motors can also be used. Each motor is coupled either directly to a drive
sprocket on which a belt drive chain is mounted, or through a transmission to
one or more drive socket.
During development of injector head it has been found that synchronized chain
blocks reduces wear on the continuous elongate device (CED) and prevents
fatigue of the continuous elongate device.
With two drive motors the belt drive chains are driven independently of each
other on each side of the continuous tubing ie. the chains are driven without
synchronization gears. There is a constant torque on the motors.
The chain blocks could in the initial position be synchronized ie the chain
blocks
from the two independent chains are oppositely positioned in the same
horizontal plane. Due to slightly different lengths of the chains, different
rotation
speed of the drive sprockets etc the chain blocks will after a while be
unsynchronized, ie the chain blocks from the two independently chains will not
be positioned in the same horizontal plane.
CA 02871825 2015-01-29
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The two oppositely chain blocks will grip the continuous tubing at slightly
different time.
This will lead to wear and possible fatigue of the continuous tubing because
one
the first chain blocks on the first chain will engage with the continuous
tubing
prior to second chain blocks on the second chain. The first chain blocks will
also
engage the continuous tubing at another angle than the second chain blocks.
This results in that the first chain blocks must travel a longer distance than
the
second chain. The difference is small typically 0,1 mm per meter continuous
tubing, but the difference between the chain blocks could accumulate to an
alterations of position or the loss of friction between the continuous tubing
and
the chain blocks.
To compensate for this uneven rotation of the chains, there have been
developed injector head where the chain blocks are rotated synchronously
during all movement of the continuous tubing in or out of the well. This has
been
obtained by using toothed wheel that are mounted on each of the chain drive
shafts and interconnected so that both chains are rotated at the same speed
and have same position. The toothed wheels are synchronized mechanically in
order to obtain the chain block in parallel, opposite positions. This
synchronizing
of the chain could cause wear and fatigue of the continuous tubing and loss of
the lifting force. The chains will rotate around the toothed wheel with the
same
speed in order to maintain the chains in a synchronized position. This leads
to
large internal forces within the system due to loss of friction between the
chain
blocks and the continuous tubing. The chain blocks could slip when they are in
contact with the continuous tubing and this could cause damage to the
continuous tubing. The synchronized toothed wheel and the chain blocks will in
this solution have different speed and are working against each other.
In a system without synchronized toothed wheels the chains will rotate with
different speed and the chain blocks will not be synchronized after a while.
This will lead to wear and possible fatigue of the continuous tubing because
the
first chain blocks on the first chain will engage with the continuous tubing
prior
to second chain blocks on the second chain. The first chain blocks will also
CA 02871825 2015-01-29
Now.
engage the continuous tubing at another angle than the second chain blocks.
This results in that the first chain blocks must travel a longer distance than
the
second chain. The difference is small typically 0,1 mm per meter continuous
tubing, but the difference between the chain blocks could accumulate to an
alterations of position or the loss of friction between the continuous tubing
and
the chain blocks.
OBJECTS OF THE INVENTION
According to one aspect of the present invention it is one objection of the
present invention to provide a system that measure the position of two
opposite
chain blocks position on either side of the continuous tubing relative one
another. If the chain blocks are not synchronized, the chains on both sides of
the continuous tubing are adjusted in the horizontal direction so that the
chain
and chain blocks will rotate synchronously at both sides of the continuous
tubing.
SUMMARY OF THE INVENTION
In one embodiment of the invention an injector head comprising a pair of
oppositely located, cooperatively movable, segmented continuous belt drive
chains, said each belt drive chain running over a respective pair of drive
sprockets and tension sprockets, wherein a tubing receiving section is defined
between the belt drive chains, said tubing receiving section having a tubing
section centerline extending through the center of the tubing receiving
section,
said injector head having an injector centerline extending through the
centerline
of the injector head, said injector centerline and said tubing section
centerline
being substantially aligned in the longitudinal direction in an initial
position, a
pair of elongate counter-force members is positioned at each side of the
tubing
receiving section. The injector head being distinctive in that said injector
head
has at least one actuator adapted to move at least one of said elongate
counter-
force member in order to bring the tubing section centerline out of alignment
with said injector centerline.
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In another embodiment of the invention an injector head comprising; a pair of
oppositely located, co-operatively movable, segmented continuous belt drive
chains, said each belt drive chain running over a respective pair of drive
sprockets and tension sprockets, said each running belt drive chain
comprising an inner flight and an outer flight, said respective inner flight
and
outer flight extending between said sprockets, at least a portion of said
respective inner flights defining a tubing receiving section for a coiled
tubing.
The invention being distinctive in that said injector head comprising at least
one
roller arranged in contact with a portion of one of the inner flights, said at
least
to one roller is moveable to displace at least said portion of said inner
flight.
Preferable embodiments of the injector head are defined in the dependent
claims, to which reference are made.
An exemplary embodiments of the injector head according to the invention
comprising a pair of oppositely located, co-operatively movable, segmented
continuous belt drive chains, each belt drive chain comprising gripper blocks,
said each belt drive chain running over respective pair of sprockets, wherein
a
tubing receiving section is arranged between the belt drive chains and having
a
tubing receiving section centerline
a pair of elongate counter-force members positioned at each side of the tubing
receiving section. The injector head is distinctive in that said injector head
having means for moving the elongate counter-force members in a direction
along a plane parallel to the tubing receiving section centerline and
perpendicular to a rotational axis of the sprocket, and inclined to the tubing
receiving section centerline, thereby moving the tubing receiving section
centerline in the same direction.
BRIEF DESCRIPTION OF THE INVENTION
Having described the main features of the invention above, a more detailed
and non-limiting description of non-limiting embodiments of the conveyor
apparatus according to the invention and aspects thereof is given below, with
reference to the attached drawings.
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Figure 1 is a principle view of the injector head according to an embodiment
of
the invention.
Figure 2 is a perspective view of the injector tube according to the
invention.
Figure 3 is a perspective view of the injector tube according to the invention
shown without the frame.
io Figure 4 is a sectional view of the injector tube according to the
invention shown
without the frame.
Figure 5 is a detailed view of synchronized chain blocks.
Figure 6a-f shows principle drawing of the running of the injection head
according to one embodiment of the invention which uses regulators that moves
the skate.
Figure 6a-6c shows an injector head with belt drive chains where the roller
means are attached to the chain blocks.
Figure 6d shows an injector head with belt drive chains where the roller means
are attached to the skate.
Figure 7a-7d shows a principle drawing of the running of the injector head
according to another embodiment of the invention where there are arranged
separate regulators on each side of the skates which have the purpose of
maintaining the same position between the skate and move the skate in the
horizontal direction.
Figure 8a-8b shows a principle drawing of another embodiment of the invention
with at least on roller moving a portion of the belt drive chain.
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Figure 9 shows a block diagram of the adjusting process of the chain in the
injector head.
Figure 10a and 10b shows a principle drawing of an embodiment of the
invention where the injector head drive unit is moved.
DETAILED DESCRIPTION OF THE INVENTION
The following describes preferred embodiments of the conveyor apparatus of
the present invention and which is exemplary for the sake of understanding the
to invention and non-limiting.
In the present context, the term "injector head" is to be construed as being
synonymous with the term conveyor apparatus as defined in the claims.
Further, the term "counter-force member" is synonymous with the term "skate"
frequently used in the art.
All throughout the specification including the claims, the words "continuous
tubing", "skate", "belt drive chain", "actuator", "coiled tubing", "borehole
",
"wellhead", "lubricator strings", "bearing", "BOP", "injector head", "sensor",
"control system", "roller" are to be interpreted in the broadest sense of the
respective terms and includes all similar items in the field, known by other
terms, as may be clear to persons skilled in the art.
Restriction/ limitation, if any, referred to in the specification, is solely
by way
of example and understanding the present invention. More specifically,
hereinafter, the term "coiled tubing" has been referred to for the sake of
convenient understanding of the invention. It should be understood that
"coiled
tubing" also includes other similar continuous tubing as may be known to
persons skilled in the art of the present invention. Further, it will be
appreciated
by the expert in the art that the invention is also applicable to other
continuous
elongate devices (CED's), such as rods, wires or wirelines.
Although the injector head is, in a currently preferred mode of operation,
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primarily to be used for operation with coiled tubing, the use of the injector
head
in conjunction with other CED's lies within the scope of the invention.
It should also be understood that the orientation of some of the apparatus
components may exhibit configurations other than those shown in the
drawings, without deviating from the principle of the invention, and such
different configurations which to not affect the overall operation of the
apparatus are to be construed as merely technical equivalents within the scope
of the present invention. The term upper and lower are used only to simplify
the
description of the invention.
The various essential aspects of the injector head will now be described in
more
detail with reference to Figures 1-9.
The figures illustrate the same representative injector but with different
examples of the synchronization.
The injector head 2 enables the injection of a continuous tubing 7 down
through
the injector head 2 and then through a lubricator strings (not shown) located
between the apparatus 2 and the wellhead (not shown), suitably via a BOP
(blow out preventer) to enable insertion of tools (not shown) in the wellhead
and
further into a well below (not shown) or up through the injector head 2 by
pulling
action enabling retrieval of the tool from the wellhead and the well below.
Figure 1 shows a perspective view of the injector head 2. All the details of
the
invention is not present but it is a simplified drawing of a typical injector
head 2
according to the invention.
The injector head 2 comprising a pair of upright, cooperatively movable,
segmented, continuous belt drive chains 21, 22. The first continuous chain 21
and the second continuous chain 22 are oppositely located and installed in a
frame 23. The chains 21, 22 form parts of two separate chain system arranged
on both sides of the continuous tubing 7.
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Each of the chain 21, 22 comprises a plurality of interconnected tubing chain
blocks 24a, 24b and are respective running over a chain drive sprockets 25a,
25b and a tension sprocket 26a, 26b. In the figure it is shown that the
tension
sprocket 26a, 26b is arranged beneath the drive sprocket 25a, 25b. (Figure 3).
Each of the sprockets 25a, 25b is connected to a chain drive and a powerful
torque creating motor 27a, 27b. The motor 27a, 27b is suitably a hydraulic
motor, but could just as well be an electric or pneumatic motor. A gear 20a,
20b
is also arranged in connection with each of the motors 27a, 27b.
to The motors 27a, 27b and gears 20a, 20b are each connected to in one end
to a
drive shaft 19a, 19b extending through each of the drive sprockets 25a, 25b.
At the opposite end of the drive shaft there is arranged a sensor 40a, 40b.
There are arranged at least one sensor, but in the figure there are shown two
sensors 40a, 40b. The sensors could measure the position of two oppositely
positioned chain blocks 24a, 24b attached to the first chain 21 and second
chain 22. The sensor cooperates with a control system and adjusting means to
correct the positioning of the opposite chain blocks. The sensor could for
instance be a chain speed encoder which converts the angular position or
motion of the shaft to an analog or digital code.
The invention is applicable with injector heads running without
synchronization
gear. The constant torque on the motors gives different speed on the first
chain
21 and second chain 22. The sensors or chain speed encoder 40a, 40b will
then register the speed and a regulator will adjust the position of the skate
32a,
32b which lead to synchronized chain blocks 24a, 24b.
The invention is also applicable with toothed drive sprockets which are
attached
together to drive the belt drive chains synchronously, ie injector head
running
with synchronized gear. With the chain running with constant torque on motors
the synchronization gear will synchronize the chain blocks 24a, 24b, sensors
ie
shaft torque sensors 40a, 40b will register torque differences and a regulator
will adjust the center position of the skate.
CA 02871825 2015-01-29
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Pl. 21) N Oil
A first counterforce elongate member 32a is extending between said drive
sprocket 25a and tension sprocket 26a and a similar second counterforce
elongate member 32b is extending between said drive sprockets 25b and said
tension sprocket 26b. The first and second elongate member are arranged on
each side of the continuous tubing 7 and in contact with each of the
respective
chains 21, 22. The longitudinal space between the chains 21, 22 where the
continuous tubing are led through is defined as a tubing receiving section 7'.
The first and second counterforce elongate member 32a, 32b will hereinafter be
called "skates".
lo
The provision of the skates 32a, 32b is to make sure that a gripper block 33a,
33b attached to the chain block 24a, 24b sufficiently engages the continuous
tubing 7 when it is forcibly driven through the injector head 2.
In order to adjust the transverse position of both skates and their mutual
distance there is provided a plurality of clamping force devices 28 in the
transverse position of the skate 32a, 32b and the continuous tubing 7. These
clamping force devices 28 having at least one actuator 29, preferably one
actuator 29 connected to each of the clamping force devices 28. This could for
instance be a hydraulic cylinder or ram. The clamping force device 28 have
also
customized elongate rods 30. These racks or rods 30 are extending on either
transverse side of the chains 21, 22 and powered by the at least one actuator
29.
In Figure 2, 3 and 4 the injector head according to the invention is shown in
greater detail. In Figure 3 and 4 the injector head is shown without the frame
2.
Each of the chain blocks 24a, 24b comprises interconnected tubing gripper
shoe carriers 37a, 37b with roller means (not shown) configured to roll in the
longitudinally direction of the skate 32a, 32b on each side of the tubing 7.
The
tubing gripper shoe carriers 37a, 37b arranged on the opposite side of the
gripper block 33a, 33b. The chain block 24a, 24b comprising the shoe carrier
37a, 37b and the gripper block 33a, 33b.
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1,37'1,N01)1
The figures further shows a pressure device 34a, 34b attached to each of the
chain systems. The pressure device 34a, 34b is in one end connected to a shaft
36 through the respective tension sprocket 26a, 26b and in the other end
connected to the frame 2. The purpose of the pressure device is to make sure
that the chain 21, 22 is held tightly around each of the respective sprockets
25a,
26a and the sprockets 25b, 26b by pushing the sprocket 26a, 26b downwards
and to avoid slack in the chain 21, 22. The pressure device 34a, 34b comprises
for instance a tension cylinder that regulates the distance between the
tension
sprocket 26a, 26b and the frame 23 in the vertical direction.
Another purpose of the pressure device 34a, 34b is to allow a little movement
of
the chain 21, 22 when one of the chain 21, 22 is moved towards an injector
head centerline 45. This will be described further below.
Position sensors 40a, 40b are attached to an end of a shaft extending through
each of the upper sprocket 25a, 25b. The position sensors could also be
attached to other parts of the injector head suitable for measuring the
position,
angle difference ,speed or torque etc. of the opposite chain 21, 22 or chain
blocks 24a,24b.
The purpose of the sensors 40a, 40b is to measure the position, torque
difference, speed difference, angle difference etc of the chain blocks 24a,
24b
on each side of the tubing receiving section 7'. The chain blocks 24a, 24b and
consequently the gripper blocks 33a, 33b are synchronized when the chain
blocks 24a, 24b on each side of the tubing receiving section 7' are positioned
in
the same horizontal plane. There are different ways to measure the position of
two oppositely arranged chain blocks 24a, 24b. This could for instance be
performed by measuring two opposite chain blocks 41a, 41b that initially
engage with the continuous tubing 7, that is what angle or speed the initial
chain blocks 41a, 41b engage with the continuous tubing 7 and difference
between the two opposite initially chain blocks 41a, 41b.
Synchronized chain blocks 24a, 24b are shown in figure 5. To be synchronized
the top of the chain blocks 24a, 24b are arranged in a same plane 18a
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extending through the top boundary of a pair of chain blocks 24a, 24b arranged
on the two opposite chains 21, 22. The bottom of the chain blocks 24a, 24b are
also arranged in the same plane 18b extending through the bottom boundary of
the chain blocks 24a, 24b. The plane 18a and 18b are substantially parallel.
The gripper block 33a, 33b of each chain blocks 24a, 24b will in this position
engage equally with both sides of the continuous tubing 7.
When the tubing 7 is pulled or pushed through the injector head 2, one of the
gripper block33a, 33b attached to the first or second chain 21, 22 will tend
to
to engage with the continuous tubing 7 before the corresponding gripper
block33a,
33b attached to the opposite first or second chain 21, 22. This will after a
while
lead to unsynchronized chain blocks 24a, 24b. This again could result in wear
and fatigue on the tubing.
The chains 21, 22 are unsynchronized when the chain blocks 24a, 24b are not
arranged in the same plane 18a, 18b when interconnecting with the continuous
tubing 7.
In order to maintain the chain blocks 24a, 24b to be synchronized throughout
the whole feeding/pulling of the continuous tube 7, there are arranged at
least
one inner adjustment actuator 35. The at least one inner adjustment actuator
35
are in the figures 2, 3 and 4 attached to one of the skates 32a, 32b. There
could
be several inner adjustment actuator 35 attached to one of the skates 32a or
the skate 32b or both.
In the figures there are shown two inner adjustment actuator 35 attached to
the
second skate 32b but there could be more than two or just one adjustment
actuator 35. The inner adjustment actuator 35 could optionally be attached to
the first skate 32a. The inner adjustment actuator 35 could for instance be
hydraulic, pneumatic or electric driven and has the purpose of moving the
skate
32a, 32b attached to the inner adjustment actuator 35 towards the tubing 7 or
away from the tubing 7. The tubing 7 will then be moved accordingly in the
transverse direction. The skates 32a, 32b are fixed by the clamping force
device
28 in a distance corresponding to the continuous tubing from each other. The
CA 02871825 2015-01-29
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second skate 32b will move accordingly of the first skate 32a in the same
direction.
Figure 6a-c shows the principle of the running of the injection head 2
according
to one embodiment of the invention.
In figure 6a the chain blocks 24a, 24b and the corresponding gripper blocks
33a, 33b are in a synchronized position. In this position a tubing section
centerline 46 extending through the center of the tubing receiving section
7'are
aligned and congruent to an injector centerline 45 extending through the
centerline of the injector head 2. This could be a start or initial position
of the
pulling/pushing of the tubing 7 in the injector head 2.
The tubing section centerline 46 is defined by the centerline of the space
is between the first chain 21 and second chain 22 where the continuous
tubing 7
is normally positioned when pushed or pulled into or out of the well.
In Figure 6b the gripper block 33a of the first chain 21 tend to engage the
continuous tubing 7 slightly prior to the gripper block 33b of the second
chain
22. To prevent the gripper blocks 33a, 33b and the chain blocks 24a, 24b to
have unsynchronized positions, the inner adjustment means 35 pulls the
second skate 32b and therefore also the chain blocks 24a, 24b interconnecting
the continuous tubing 7, the tubing 7 and the first skate 32a, towards the
adjustment means 35. The tubing section centerline 46 is moved away from the
injector centerline 45. (In the figure 7b the skates 32a, 32b and the
continuous
tubing 7 are moved to the left from the centerline 45 of the injector head 2.)
The
drive sprocket 25a and the tension sprocket 26a are not moved in the
horizontal
direction. Since only the first chain blocks 24a abutting the continuous tube
7 is
moved to out of position this will lead to a movement of the tension sprocket
26a in the vertical direction as a compensation because the circumference of
the chains 21, 22 have to be the same in all positions of the chain 21, 22.
When the skates 32a, 32b together with the continuous tubing 7 and the chain
blocks 24a, 24b are shifted to the position shown in Figure 7b, the gripping
CA 02871825 2015-01-29
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\
shoes 33a of the chain blocks 24a on the first chain 21 will have a slightly
longer distance to rotate from the position on top of the drive sprocket 25a
to
the engagement with the continuous tubing 7.
The gripper block 33b attached to the chain block 24b on the second chain 22
will correspondently have a shorter distance from the top of the sprocket 25b
to
a position where it engages with the continuous tubing 7. The inner adjustment
actuator(s) 35 will position the skates 32a, 33b in a position so that the
gripper
blocks 33a, 33b on two oppositely corresponding chain blocks 24a, 24b are
io engaging the continuous tube 7 on opposite sides of the tube 7
synchronously.
Figure 6c shows the opposite case than in Figure 6b. The gripper block 33b of
the second chain 22 tend to engage with the continuous tubing slightly prior
the
gripper block 33a of the first chain 21. To compensate for this and to achieve
synchronized chains 21, 22 the adjustment actuators are moving the second
skate 32b connected to the adjustment actuator 35 away from the adjustment
actuator 35. The first skate 32a, the continuous tubing 7 and the gripper
block
33a, 33b of the chain blocks 24a, 24b abutting the continuous tubing 7 are
moved correspondently in the same direction. The tubing section centerline 46
is moved away from the injector centerline 45 (In figure 7c the first and
second
skates 32a, 32b and the continuous tubing 7 are moved to the right out of
alignment of the injector centerline 45.
The skates 32a, 32b and chains 21, 22 in figure 6b and 6c are moved in a
direction along a plane parallel to the tubing receiving section centerline
and
perpendicular to a rotational axis of the sprockets (25a, 26a).
To compensate for the difference between the gripper blocks 33a, 33b, there
are arranged a pair of sensors 40a, 40b which could measure an initial
gripping
shoes 41a, 41b that initially engages with the continuous tubing 7. The
sensors
40a, 40b could also measure other different parameters in order to analyze if
the chain blocks 24a, 24b for instance the initially gripper blocks 41a, 41b
are
synchronized or not.
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4411`,i
The different parameters could be for instance measure of the speed or
difference in the angle of the initially gripper blocks 41a, 41b. The sensor
40a,
40b could also measure the torque difference on the drive shaft 19a, 19b for
instance if the injector head are running with synchronized gear, as described
s earlier.
The sensors 40a, 40b are connected to a control system (not shown)
cooperating with the actuator. Based on the measurement of the sensor the
actuator will compensate for any unsynchronized movement of the chains by
moving the skates in the horizontal direction.
There are two different types of skates. These are illustrated in the Figure
6a-c
and Figure 6d.
In Figure 6a-6c the roller means 17a, 17b are connected to the skate 32a, 32b
is and that the tubing gripper shoe carriers 37a, 37b attached to the chain
21, 22
having an even surface where the roller means 17a, 17b are configured to be in
contact with and roll on.
Figure 6d shows the other principle which are described earlier, where the
roller
means 17a, 17b are connected to the belt drive chain 21, 22.
In figure 6e and 6f, the possible position of the sensors 40a, 40b are shown.
Figure 7a-7d shows a principle drawing of another embodiment of the running
of the injector head according to the invention.
In this figures the inner adjustment actuator and the clamping force device
which are described as independently actuator in the previous embodiment, are
arranged in the same adjusting device 50a, 50b. There are arranged at least
one adjusting device 50a, 50b on each side of the continuous receiving section
7. A first adjusting device 50a is connected to the first skate 32a and a
second
adjusting device 50b is connected to the second skate 32b. The figure only
shows one adjusting device on each side of the skates 32a, 32b, but there
could be more than one adjusting device 50a, 50b attached to each of the
skates 32a, 32b.
CA 02871825 2015-01-29
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=,
The function of the embodiment of figure 7a-7d is in principle the same as in
figure 6a-6c but instead of one active skate which is moved by the adjustment
actuator 35 in Figure 6a-c there are similar adjustment devices 50a, 50b that
both can actively position the skates 32a, 32b. If the chain blocks 24a, 24b
are
not running synchronously, the adjusting devices 50a, 50b will compensate for
this by actively moving the first or second skate 32a, 32b so that the chain
blocks 24a, 24 are synchronized. They are interacting so that the clamping
force between the skates 32a, 32b are maintained.
Figure 8a- 8b shows another possible embodiment of the invention.
The chains 21, 22 comprises of an inner flight 51a, 51b which are extending
from the drive sprockets 25a, 25b two the tension sprocket 26a, 26b. At least
a
part of the inner flight 51a, 51b is engaging or gripping the continuous
tubing 7
is that are pushed of pulled through the injector head 2.
The outer part of the chain 21, 22 is referred to as an outer flight 52a, 52b.
The
outer flight 52a, 52b is extending from the tension sprocket 26a, 26b to the
drive
sprocket 25a, 25b on the outside of each of the inner flights 51a, 51b.
In these figures there are arranged first rollers 53a, 53b in connection with
the
upper portion 54a, 54b of the inner flights 51a, 51b and additionally there
are
arranged second rollers 53c, 53d in the lower portion 55a, 55b of the inner
flight
51a, 51b. The upper and lower portion of the inner flights are the part of the
chains restricted respectively between the drive sprockets 25a, 25b and the
upper part of the skate 32a, 32b and the lower part of the skate 32a, 32b and
the tension sprocket 26a, 26b.
The rollers 53a, 53b, 53c, 53 are connected to actuators that will move the
rollers towards the injector centerline 45 and therefore also move the upper
and/or lower portion of the inner flights 51a, 51b towards the injector
centerline
45. They could for instance be connected to the actuators through brackets
55a,
55b, 55c, 55d
CA 02871825 2015-01-29
! '
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21)%00i (d
The skates 32a, 32b are in this embodiment held in a fixed position. Likewise,
the outer flights 51a, 51b will have a fixed distance to the injector
centerline 45
and will not move in relation to this.
The rollers 53a, 53b, 53c, 53d could be moved independently of each other.
In Figure 8a there is shown a position where the roller are positioned at an
equal distance from the injector centerline 45.
An angle al which is defined as the angle between the first chain 21 and the
to injection centerline. An angle a2 is defined as the angle between the
second
chain 22 and the injection centerline, The angle al and angle a2 are in this
position equal.
In Figure 8b the roller 53a, 53d which are in communication with the first
chain
21 are moved towards the injector centerline 45 so that the angle al is
smaller
than the angle a2 to compensate for unsynchronized movement of the chains.
Similarly could the rollers 53b, 53c which are in communication with the
second
chain 22 move towards the injector centerline 45 so that the angle a2 is
smaller
than the angle al.
The same applies for the previous mentioned embodiments where the skate
32a, 32b or the whole injector drive unit is moved. The angle al or a2 will
decrease according to the movement of the skates 32a, 32b or injector drive
unit. This embodiment where the whole injector drive unit is moved is shown in
Figure 10a and 10b.
Figure 9 is a block diagram of the adjusting process of the chain in the
injector
head. The adjusting process is a continuous process to secure that the chains
21, 22 are running synchronously throughout the injection process. The sensors
will monitor when the chains 21, 22 are unsynchronized and send signal to the
actuator 35, 50a, 50b, 54a, 54b, 54c, 54d to adjust the position of the skates
32a, 32b or rollers 53a, 53b, 53c, 53d if two oppositely orientated chain
blocks
are not synchronous.
CA 02871825 2015-01-29
(
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,(k1
The movement of the actuators depends on which of the chains 21, 22 that
needs to be adjusted and brought into synchronization with the other.
The present invention has been described with reference to preferred
embodiments and aspects thereof and related to the accompanying drawings
for the sake of understanding only and it should be obvious to persons
skilled in the art that the present invention includes all legitimate
modifications within the ambit of what has been described hereinbefore
and claimed in the attached claims.
