Note: Descriptions are shown in the official language in which they were submitted.
CA 02450223 2003-12-08
DOWNHOLE FLOW CONTROL DEVICES
Background of the Invention
Field of the Invention
The invention relates to oil well technology. More particularly, the invention
relates to a downhole fluid flow and pressure equalization control and choke
devices.
Prior Art
Flow control has been a concern of the oil drilling industry since the first
well
produced a gusher like that of spindle top in Texas on January 10, 1901.
Initially, flow
control was focused upon surface based apparati, however, as technology
advanced and
multiple production zone/multiple production fluid wells grew in popularity,
flow
control downhole has become increasingly important.
One particular prior art device which has been very effective is the CM
sliding
sleeve commercially available from Baker Oil Tools, 6023 Navigation Boulevard,
Houston Texas 77011. The sleeve employs one outer housing with slots and one
inner
housing with slots. The slots are alignable and misalignable with axial
movement of the
inner housing relative to the outer housing. The tool is effective for its
intended purpose
but does not provide any selectivity regarding where on the circumference flow
is
desired. Other valuing and choking devices are also available in the prior art
but there is
still a need for more efficient devices and specific devices to function where
others have
not proved effective. Moreover, devices which function with less or no input
from the
surface are also likely to have a significant positive impact on the industry.
Summary of the Invention
The above-discussed and other drawbacks and deficiencies of the prior art are
overcome or alleviated by the downhole flow control devices of the invention.
In connection with all of the following embodiments and sub embodiments of
the invention it will be understood that these include (although could be
employed
without) downhole electronics including processors, sensors, etc., in the
downhole
environment which perform decision making tasks based upon input from sensors
and
or from preprogramming and or from surface input. These intelligent systems
are more
CA 02450223 2003-12-08
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fully discussed in U.S. Patent No. 5,597,042 which is assigned to Baker Hughes
Incorporated who is the assignee hereof.
In the first embodiment of the invention a cylindrical tool having a plurality
or
multiplicity of individual valve bodies is provided. The valve bodies are
individually
activatable to meter flow circumferentially around the tool. Among the
individual valve
bodies, three subembodiments are most preferred. In the first subembodiment
each
individual valve is arranged to be rotationally adjustable; in the second
subembodiment,
which is of very similar appearance to the first, the valve is arranged to be
adjustable to
be longitudinally slidable; and the third subembodiment provides a
conical/cylindrical
spear valve and a conical/cylindrical mating structure which allows fluid to
flow when
the spear is not fully urged into the cone.
With all of the subembodiments of the first embodiment of the invention,
metered control is possible as well as circumferential control. It will be
understood that
among the valve bodies, differing subembodirnents may be assembled within one
tool.
Actuation of the valve bodies of any of the subembodiments may be by way of
electric motor, hydraulic or pneumatic pressurized flow or otherwise. Another
feature of
the invention is a downhole electronics package that allows for the downhole
decision
making sensing and powering of the downhole tools of the invention.
In a second embodiment of the invention, a toroidal inflatable/deflatable
bladder
is disclosed which provides a centrally located orifice through which fluid
may flow
when the bladder is not fully inflated thus occluding the orifice. An
advantage of the
device is that it is very versatile and is capable of a great many closing and
opening
cycles in varying degrees without failure.
In a third embodiment of the invention a dependent sleeve choke mechanism is
disclosed. The tool includes inner and outer sleeves which are disposed one on
either of
the inner and outer diameter of the housing of the tool. The inner and outer
sleeves are
fixedly connected to one another such that the sleeves move in tandem to
conceal or
reveal openings in the housing through which fluid may flow. Actuation may be
by
electric, hydraulic or pneumatic motor and a gear train or can be by
conventional
shifting tools. Position sensors are preferably employed to provide
information
CA 02450223 2003-12-08
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regarding the position of the sleeve. Other sensors as disclosed in Baker Oil
Tools U.S.
Patent No. 5,597,042 issued January 28, 1997 which is assigned to the assignee
hereof.
In a fourth embodiment of the invention, similar to the third embodiment, an
independent sleeve choke mechanism is disclosed. In the independent mechanism,
the
inner and outer sleeves are not connected to one another and may be actuated
independently of one another. Actuation may be by a single motor, solenoid
switchable
to the desired gear train or may be two motors independent of one another. The
sensing
or processing as discussed above are applicable to this embodiment as well.
In general, with respect to the above, position sensors such as linear
potentiometers, linear voltage displacement transducers (LVDT) resolvers or a
synchro
is employed to determine position of either the dependent or independent
sleeve choke
devices. Moreover, in both the third and fourth embodiments, shear out
mechanisms are
provided in the event of failure of the powered actuation system so that the
tool may be
conventionally actuated with for example a shifting tool.
In a fifth embodiment of the invention, a nose seal choke mechanism is
disclosed. The nose seal choke mechanism includes a moveable sleeve on the
inside of
a ported housing which regulates flow by obstructing the amount of port area
open to
flow. Flow is restricted by the unique stepped out nose on the inner sleeve.
The
mechanism provides an advantage by shielding seals from flow through the
device.
This is beneficial because it prevents seals being washed out or flow cut
during
operation of the choke mechanism. The device is actuatable by powered means
or, if
such means fail, by conventional means after shearing. This device also
provides a dual
back up operation by adding a second shear out mechanism and a second flow
control.
A sixth embodiment of the invention is a helical key choke mechanism. This
device includes helical grooves around the O.D. of a ported housing and keys
set within
the grooves that are moveable based upon the movement of a sleeve which is
attached to
the keys either directly or through an intermediary. By moving the keys into
the helical
flow path, flow is restricted; by moving the keys out of the flow path, flow
can be
increased. Preferably there are a total of four keys used so that the flow
area is
maximized through the annular area while still promoting accurate and
substantial
control of fluid. The inner sleeve, to which the keys are operably attached,
is actuated
CA 02450223 2003-12-08
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by motors of electrical, hydraulic or pneumatic modes of operation or
conventionally
after shear out of the shear release sleeve.
In a seventh embodiment of the invention, a spiral choke mechanism is
disclosed
which enlarges or restricts port openings in a ported housing by rotation of a
spiral
choke device. Rotation of the choke device changes the throat opening between
the
ported housing and the port in the spiral choke. This enables reliable
metering of the
flow from the well annulus to the tubing string. Sensors are used to determine
the
position of the metering spiral choke device. Actuators for the device are
similar to
those discussed above, and a shear out structure is supplied for removing the
powered
actuator from contact with the choke device. In this embodiment the shifted
operation is
a one time permanent closure operation.
An eighth embodiment of the invention is an orifice choke mechanism wherein a
moveable sleeve inside an orifice housing having a plurality of hard material
orifices
regulates fluid flow by obstructing number of orifices open to flow. In this
embodiment
the entry of the orifices is square edged to provide a pressure drop. The
device is
preferably actuated by a motor and gear train assembly which includes spur
gears and a
drive screw. A shear out mechanism is incorporated to allow the sleeve to be
conventionally actuated in the event that the powered actuators should fail.
Accordingly, in one aspect of the present invention there is provided a
downhole
choke mechanism comprising:
a cylindrical inner housing having at least one helical groove cut on an outer
diameter thereof;
a cylindrical outer housing protecting said inner housing and having at least
one
port therein; and
at least one key received in at least one key slot of said inner housing and
moveable into said at least one groove to choke flow of a fluid moving in said
at Ieast
one groove.
The above-discussed and other features and advantages of the present invention
will be appreciated and understood by those skilled in the art from the
following detailed
description and drawings.
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Brief Description of the Drawings
Referring now to the drawings wherein like elements are numbered alike in the
several FIGURES:
FIGURE 1 is a cross section view of the multiple valve body flow control
device
of the invention;
FIGURE 2 is a transverse section of an individual rotary valve body structure
of
the invention;
FIGURE 3 is a transverse section of an individual sliding valve body structure
of
the invention;
FIGURE 4 is a transverse section of an individual conical/cylindrical valve
body
structure of the invention;
FIGURE 5 is a side view of the tool of the invention illustrating the windows
in
the outer sleeve and the valves visible through the windows;
FIGURE 6 is a side view of the invention with the windows illustrated in a
staggered pattern;
FIGURE 7 is a side view of a pressure controlled valve in accordance with the
present invention;
FIGURE 8 is an end view of the pressure controlled valve shown in FIGURE 1;
FIGURES 9-16 are an illustration of a third embodiment of the invention
wherein an inner and outer choke sleeves are attached to one another;
FIGURE 9A is a cross-section view taken along section lines 9A-9A in FIGURE
9;
FIGURE 11A is a cross-section view taken along section lines 11A-11A in
FIGURE 11;
FIGURE 11B is a cross-section view taken along section lines 11B-11B in
FIGURE 11;
FIGURE 11 C is a cross-section view taken along section lines 11 C-11 C in
FIGURE 11A;
FIGURE 11D is a cross-section view taken along section lines 11D-11D in
3 0 FIGURE 11 A;
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FIGURES 17-21 represent a fourth embodiment of the invention wherein an
inner and outer sleeves are not attached to one another;
FIGURE 17A is a cross-section view taken along section lines 17A-17A in
FIGURE 17;
FIGURE 17B is a cross-section view taken along section lines 17B-17B in
FIGURE 17;
FIGURE 17C is a cross-section view taken along section lines 17C-17C in
FIGURE 17;
FIGURE 17D is a cross-section view taken along section lines 17D-17D in
FIGURE 17A;
FIGURE 22 is a schematic perspective view of the drive mechanism of the
fourth embodiment of this invention;
FIGURES 23-27 represent a fifth ernbodirnent of the invention wherein a nose
seal choke mechanism is illustrated;
FIGURES 28-34 illustrate a helical key choke mechanism of the invention;
FIGURE 31A is a cross-section view of the invention depicted in FIGURES 28-
34 taken along section lines of the same number, letter combination;
FIGURE 35 is a plan view of the helical grooves and keys of the invention
depicted in FIGURES 28-34 the pipe having been separated and laid flat;
FIGURE 36 is a perspective view at the same section of the invention of
FIGURES 28-34;
FIGURES 37-41 depict an elongated view of a spiral choke embodiment of the
invention;
FIGURE 39A is a cross-section of the embodiment illustrated in FIGURES 37-
41 taken along section lines of the same number, letter combination;
FIGURES 42-46 illustrate an elongated view of another embodiment of the
invention providing an orifice choke mechanism; and
FIGURE 45A is a cross-section view of the invention illustrated in FIGURES
42-46 taken along section lines bearing same number, letter combination.
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Detailed Description of the Preferred Embodiments
Refernng to FIGURE l, one of skill in the art will appreciate that the tool
comprises outer housing 10 having a plurality or multiplicity of valve body
bores 12
(could also be a single valve body bore if desired) which bores 12 are
arranged
preferably annularly around an inner sleeve 14 and an axial void 16. Brief
reference to
FIGURES 5 and 6 will put the tool in perspective for those of skill in the
art. It will be
appreciated that FIGURES 5 and 6 are examples of locations and patterns for
windows
and that other patterns and locations are possible and are within the scope of
this
invention.
The individual valve bodies 18, discussed more fully hereunder as 18a, 18b and
18c, are operated together, individually, or in selected subgroups to access
and flow
desired fluid from desired regions within a zone. The actuation of the valve
bodies may
be by electric motor (whether regular or a stepper motor), hydraulic or
pneumatic
systems, solenoid systems whether a single solenoid is employed for all of the
valves or
each valve has its own solenoid, etc. power can be supplied by an uphole or
surface
source or a downhole source and may be batteries, capacitors, TEC wire, etc.
Complexity of the system desired will dictate whether all of the bodies 18 be
actuated at
once with a single actuator or if individual or groups be actuated which will
require
additional actuating systems or at least bridging systems within the tool.
Multiple
systems may be staggered to provide sufficient room within the tool.
Decision making with regard to openness of a particular body 18 or group if
the
same may be made downhole employing downhole intelligence technology like that
disclosed in Baker Oil Tools U.S. Patent No. 5,597,042 issued January 28,
1997. '/a inch
TEC cable is a preferable conductor although any conductor may be employed to
conduct signals and power to the actuators from a downhole intelligence system
or from
the surface.
Referring to FIGURES 2-4 the embodiments of the individual valve bodies are
illustrated. In FIGURE 2, the bore 12 is the shallowest of the embodiments
since no
longitudinal movement of valve body 18a is necessary. Rather, in this
embodiment the
body 18a is in the form of a petcock having a fluid aperture 20 which is
alignable or
misalignable to a varying degree with external window 22 leading to the
downhole
CA 02450223 2003-12-08
environment and internal window 24 leading to the axial void 16 of the tool.
The
alignment of the petcock body 18a is accomplished by rotating body 18a through
stem
26 thereof. O-rings 30 are positioned on either side of the aperture 20 to
seal the
apparatus.
Referring to FIGURE 3, slide body 18b is. illustrated. Bore 12 is deeper in
this
embodiment due to the need for misalignment of windows 22 and 24 with aperture
21
via longitudinal movement of valve body 18b. O-rings 30 are provided to seal
the
structure. Alignment of windows 22 and 24 with aperture 21 is accomplished to
a
varying degree by movement of body 18b through stem 26.
Refernng now to FIGURE 4, another longitudinally actuated valve body is
described. Cone valve 18c is essentially a frustocone with a cylindrical
extension which
mates with a similarly shaped bore 12. Metered flow is accomplished by the
degree to
which the valve body is urged into the conical/cylindrical bore 12. Windows 22
and 24
are replaced in this embodiment with staggered external opening 32 and
internal
opening 34. A fluid aperture 21 is not necessary in this embodiment. O-rings
30 are
provided to seal the structure. The scope of the frustoconical/cylindrical
embodiment of
body 18c is important because it allows for very precise metering of the fluid
flowing
therethrough.
The multiple valve body tool of the invention provides significant latitude in
construction and selectivity in flow and is, therefore, valuable to the
industry.
In a second embodiment of the invention, referring to FIGURES 7 and 8, a fluid
pressure actuated bladder valve is disclosed. The bladder of the invention is
positionable in a section of pipe such that an outer diameter thereof is
firmly attached to
the inner diameter of the pipe and the inner orifice of the bladder is open or
closed
depending upon the amount of pressure inside the bladder relative to ambient
pressure in
the vicinity of the bladder. FIGURE 7 is a side view of a pressure controlled
valve of
the present invention. A toroidal shaped bladder 44 is positioned in the
inside of a pipe
40. The bladder 44 may be bonded to the inside of the pipe 40 using an
adhesive or any
other suitable attachment arrangement which includes but is not limited to a
mechanical
attachment magnetic element inside the bladder which then pinches the wall of
the
bladder between the magnetic element and the pipe in which the bladder is
positioned.
CA 02450223 2003-12-08
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Alternatively, the bladder 44 may be simply positioned in the pipe 40 and
maintained in
the desired position by friction caused by pressure internal to the bladder.
The bladder
44 has an orifice 42 which allows fluid flow through pipe 40 when the bladder
is not
inflated. The bladder 44 is preferably made of an elastic material which can
be inflated
and deflated repeatedly without structural degradation. Pressurization and
depressurization of the bladder of the invention is effected through a control
line 46
which preferably passes through pipe 40 and extends into the interior of
bladder 44.
Control line 46 is in sealed communication with bladder. The control line 46
controls
the pressure within the bladder and can inflate or deflate the bladder 44
through
hydraulic, pneumatic or other pressure sources.
When inflated, bladder 44 will expand. Since expansion radially outwardly is
inhibited by the pipe in which the bladder is located, the expansion is
limited to radially
inward and longitudinal. Since the radial inward expansion requires less
energy, the
bladder tends to close off orifice 42, thus sealing the pipe 40. Desired flow
through the
pipe 40 can be achieved through applying a determined amount of fluid pressure
to the
bladder 44.
FIGURE 8 is an end view of the pipe 40 shown in FIGURE 7 including the
pressure controlled valve positioned inside of the pipe 40. As noted above,
the centrally
located orifice 42 may be opened or closed by deflating or inflating the
bladder 44 to
control flow through the pipe 40.
The pressure controlled valve of the present invention includes a single
moving
part, namely bladder 44, which is made from an elastic material. Therefore,
the pressure
controlled valve can withstand numerous cycles of opening and closing without
failure.
This feature makes the pressure controlled valve ideal for applications such
as downhole
flow control and other applications, where ambient conditions are adverse and
valve
maintenance or replacement is difficult.
The pressure controlled valve may be controlled from the surface of the well
or
through downhole intelligence located within the well. A representative
downhole
intelligent control is schematically illustrated in FIGURE 7 but it will be
appreciated
that the invention is also capable without the intelligent systems
illustrated. Downhole
intelligence, intelligent sensor arrangements, (e.g., position sensors,
pressure sensors,
CA 02450223 2003-12-08
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temperature sensors, etc.) and communications for communicating to a downhole
or
surface microprocessor via any conventional communication device or media such
as
telemetry devices, wireline, TEC wire, cable, etc., are beneficial to the
operation of the
above-described valve. Moreover, the downhole intelligence systems described
in U.S.
Patent No. 5,732,776 are desirable to monitor conditions including the status
of the
pressured controlled valve and initiate and execute commands. By monitoring
conditions downhole, metered adjustments of the pressure controlled valve can
be made
to boost efficiency and production of any given well. This type of downhole
intelligence
is employable and desirable in connection with all of the embodiments
disclosed herein
and while only some of the embodiments contain direct reference to intelligent
systems
and controls it will be understood that these can be for all of the
embodiments.
In a third embodiment of the invention, referring to FIGURES 9-16 a dependent
sleeve choke mechanism includes a ported housing 60 which is flanked on its
inner
diameter by inner sleeve 62 and on its outer diameter by choke sleeve 64.
Sleeves 62
and 64 are attached to one another by retaining key 66 such that a single
actuator may be
employed to move both inner sleeve and choke sleeve to full open positions or
choked
positions or anywhere in between. As one of skill in the art will understand,
the precise
actuator employed may be electric, pneumatic, hydraulic, combustion motor or
otherwise. The most preferred embodiment, however, is illustrated in FIGURES 9-
16
and employs an electric motor 70 which translates force through a gear train
located in
and supported by a gear body 102 and spur gear body 77 comprising spur gear 72
in
contact with the motor 70, which drives drive shaft 76 transmitting force
efficiently
which, in turn, meshes via spur gear 108, 110 profiles with drive screw 78.
Drive screw
78 provides a screw thread on the LD. thereof which is complimentary to an
O.D. thread
on the uphole end of drive sleeve 80. Drive sleeve 80 provides linear force to
inner
sleeve 62 via dog 116. In order to assist the gear train in transmitting force
efficiently,
there are provided several bearings 82 throughout the gear train. Further, and
to increase
the ability of drive screw 78 to impart driving force upon drive sleeve 80,
thrust bearings
84 are provided. Thrust bearings 84 are retained by thrust bearing retainers
86 which are
housed along with drive shaft 76 within gear housing 88. The gear train is
maintained
within gear housing 88 which is connected to more downhole components of the
tool
CA 02450223 2003-12-08
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via a splined connection 89 and a retaining nut 90. A seal 87 prevents
undesired fluid
passage at the uphole end, gear housing 88 is connected to motor housing 94 by
double
metal to metal seal thread 92. These connections provide an environment for
operation
of the gear train. The environment is most preferably filled with pressure
compensated
dielectric fluid. Beyond the motor housing 94 in the uphole direction, motor
housing 94
is connected to electronics housing 96. Electronics housing 96 defines an
atmospheric
chamber 98 which houses the downhole electronics processors and power sources
or
power couplers associated with the choke of the invention. It should be noted
that all of
the chokes of the invention employ similar electronics packages and similar
housings.
These elements are, therefore, not discussed in detail with respect to each
embodiment.
It will be noted that in order to prevent wellbore fluids from entering the
motor area, a
seal 104 is maintained in place by a snap ring 106.
Referring back to the gear train, more detail is provided. At the downhole end
of
drive shaft 76, the shaft is endowed with a spur gear arrangement 108 which
engages an
O.D. spur gear 110 on drive screw 78. On the LD. of drive screw 78, which is
not
readily visible from the drawing, however will be understood by one of
ordinary skill in
the art, is a threaded arrangement 112 which meshes with an O.D. thread 114 on
drive
sleeve 80. Drive sleeve 80 is connected to inner sleeve 62 by dogs 116 so that
linear
movement of drive sleeve 80 is directly translated to inner sleeve 62 and
consequently
translated through key 66 to choke sleeve 64. It should be noted that choke
sleeve 64
includes at its uphole end, a cover 118 whose purpose it is to avoid the entry
of wellbore
debris into the area in which key 66 slides. Were the debris to enter the
area, the key
may not slide as intended and the tool would need to be repaired. As can be
ascertained
from the drawing FIGURE 1 S, the port 120 in ported housing 60 can be exposed
or
closed off by the movement above described.
Seals 74 provide closure of port 122 from port 120 of the port housing 60
providing complete separation of annulus fluid from tubing fluid when the
inner sleeve
62 is placed in the downward position. Seals 74 are vn the same axial diameter
to
reduce the net force caused by differential piston areas to zero differential.
It should be noted that port 122 of the inner sleeve aligns with port 120 of
the
ported housing 60, thus rendering that part of the device fully open, prior to
the choke
CA 02450223 2003-12-08
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sleeve 64 pulling uphole sufficiently to clear port 120 from port housing 60.
This is due
to extra length on the downhole end of sleeve 64. This is an important feature
of the
invention since when choke sleeve 64 is placed in the choke position the inner
sleeve 62
is more fully open. By providing alignment of port 120 and port 122 flow
cutting of the
inner sleeve is prevented. Secondly, with the choke sleeve 64 extended in the
manner
described, erosional wear caused by flowing in the choked position does not
immediately effect the function of the device such that the inner sleeve would
be
damaged by the choke sleeve not functioning as intended. In other words, the
extended
portion of the choke sleeve 64 provides for extended life of the tool by the
effective
extra length thereof. Moreover, in order to avoid erosional wear of the choke
sleeve, a
hard wear resistant material such as tungsten carbide is either applied as a
coating to
sleeve 64 or actually makes up all or a part of sleeve 64.
At the downhole end of choke sleeve 64 in the closed position, it is abutted
against lower sub upset 124 which provides both a downhole stop for the choke
sleeve
64 and, furthermore, is slightly wider in outside diameter to protect the
choke sleeve 64
from damage during run in.
It should be noted that the motor housing is offset from the sleeve to
accommodate the motor, gear train, electronics and compensation system while
minimizing the O.D. of the tool.
In the most preferred dependent sleeve embodiment, a position sensor such as a
linear potentiometer, linear voltage displacement transducer (LVDT), resolver
or
synchro is employed. The exact location of the position sensor is not
illustrated but can
be anywhere along which linear movement is experienced or where rotary
movement is
experienced in the event that a rotary position sensor is employed.
In this as well as the other embodiments of this invention, the motor and gear
train are protected by a pressure compensated dielectric fluid. Refernng to
FIGURES
11C and 11D, two alternative pressure compensators are illustrated. Both
compensator
designs are intended to separate well fluid from the dielectric fluid with a
moveable
member to allow pressure to change within the dielectric fluid in response to
a change in
pressure of the surrounding fluid. In FIGURE 11C, the compensator is a piston
101
mounted moveably in a cylinder 103 cut in motor housing 94. The location of
the
CA 02450223 2003-12-08
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compensator cylinder is not critical and is shown, for example, in FIGURE 11A.
Cylinder 103 is open to tubing pressure through port 105 and is open to the
dielectric
fluid at the opposite end of the cylinder. The piston includes conventional
parts such as
a piston body and cap and nonelastomeric seals.
In the alternative embodiment, a bellows 107 is employed to do the same Job as
piston 101. The bellows embodiment provides the advantage of eliminating
piston seals
and increasing responsiveness to pressure changes however suffers the
disadvantage
increasing tool length due to short throw. The metal bellows is commercially
available
from Senior Aexonics.
The choke system of the invention provides f~r backup conventional shifting
tool actuation in the event of the actuator of the invention failing.
Referring to FIGURE
13, and back to dogs 116, the drive sleeve 80 may be disconnected from inner
sleeve 62
by shifting shear out sleeve 126 uphole through use of a conventional shifting
tool acting
upon shear out shoulder 138 (see FIGURE 13). Upon engaging a shear out
shoulder
138, shear out sleeve 126 is provided with sufficient shear stress to entice
shear screw
132 to fail thus allowing shear sleeve 126 to slide uphole until the shoulder
134 impacts
the downhole end of 136 of shifting sleeve 130. Upon the moving uphole of
shear
sleeve 126, dog 116 will move radially inwardly onto the downhole end 140 of
shear
sleeve 126 so that dog 116 is no longer in communication with drive sleeve 80.
The
shear out sleeve 126 when reaching its uphole extent, as discussed above,
allows snap
ring 142 to snap radially outwardly into ring groove 144 to prevent any
additional
relative movement between sleeve 126 and sleeve 62. By preventing such
relative
movement, the dog is prevented from reengaging with drive sleeve 80 due to
other well
operations.
At this point, a shifting tool of a conventional nature will be employable
upon
shifting profile 128 to actuate inner sleeve 62 and (through key 66), choke
sleeve 64 in
the uphole direction. Moving the sleeves in the uphole direction, as noted
previously,
will open the device. By employing the shifting profile 146 at the downhole
extent of
inner sleeve 62, sleeve 62 and sleeve 64 may be shifted to the closed
position. When
operating the tool in the closing process on shifting profile 146, the well
operator can be
CA 02450223 2003-12-08
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assured that a tool will not be driven beyond its proper orientation by stop
shoulder 148
which is part of the ported housing 60.
Referring to FIGURES 17-22, an independent sleeve choke mechanism is
disclosed wherein two independent movable sleeves are located on either side
of the
ported housing. The ported housing is similar to that disclosed with respect
to the
dependent sleeve choke mechanism described hereinabove and allows fluid to
flow
through the port depending upon positions of a choke sleeve and an inner
sleeve. As in
the foregoing embodiment, a choke sleeve includes a hard material either
applied to the
exterior of the sleeve or comprises part of all of the sleeve itself.
Beginning from the downhole end of the tool and referring directly to FIGURES
and 21, lower sub 200 extends upwardly to join with ported housing 202 at
threaded
connection 204 and includes seal 207. Lower sub 200 further includes a
radially
enlarged section 208 having a shoulder 206 which acts as a downstop for choke
sleeve
210. Choke sleeve 210 is actuatable in a linear manner to conceal and reveal
port 212,
15 in ported housing 202. As one of skill in the art will undoubtedly
understand, port 212
is most preferably a plurality of ports arranged circumferentially about the
invention. It
is within the scope of the invention to have as few as one port. Choke sleeve
210 is
protected by choke cover 214 which is non-moveable and is anchored to keys 216
which
extend from choke cover 214 to choke connector sleeve 218. Choke sleeve 210
includes
20 a groove 220 which allows it to slide longitudinally past keys 216. In
other words, keys
216 ride within groove 220 and prevents rotational movement of sleeve 210.
Rotational
movement must be prevented in sleeve 210 since the actuation mechanism which
provides the longitudinal movement of choke sleeve 210 is provided by a drive
screw
which without being prevented from allowing rotational movement, would merely
rotate
the choke sleeve as opposed to driving it longitudinally. Keys 216 also carry
tension
from above the tool to below by transferring the load from choke cover 214
through
keys 216 to choke connector sleeve 218. More particularly, and referring to
FIGURES
18 and 19, choke sleeve 210 continues uphole past shoulder 222 to an uphole
end
thereof having O.D. threads 224 complimentary to LD. threads 226 on choke
drive
screw 228. Choke drive screw 228 is driven by choke drive shaft 230 having
spur gear
teeth 232 at the downhole end thereof. It will be noted by one of ordinary
skill in the art
CA 02450223 2003-12-08
- is -
that bearings 234 are positioned at the downhole end of the choke drive shaft
230 to
provide for support of the drive shaft 230 and avoid drag.
An important feature of the invention includes thrust bearings 236 located on
either side of choke drive screw 228. Thrust bearings 236 provide for more
smooth
power transfer from drive shaft 230 to choke sleeve 210. Better power
transition allows
for the use of a smaller and less costly motor. Drive shaft 230 extends uphole
to its
terminus at spur gear 240. Drive shaft 230 is supported at its uphole end,
similar to its
downhole end, by bearings 234. Drive shaft 230 is driven by a motor
illustrated in
FIGURES 17A and 17D as numeral 244 through the action of solenoid 242 which
selectively engages one of the idler gears 278 in order to drive either choke
drive shaft
230 or the inner sleeve drive components 272. Refernng back to FIGURES 20 and
21
and a downhole end of the tool of the invention, inner sleeve 250 extends
longitudinally
and exists radially inwardly of port 212. Inner sleeve 250 further includes
port 252
which is alienable or misalignable with port 212 as desired. Inner sleeve 250
includes
shifting profiles 254 and 256 for conventional shifting of the sleeve in the
event of a
drive system failure. Should such failure occur, the shear screw 258 need
merely be
sheared by a tensile force exerted on, for example, profile 254. Once shear
screw 258
has sheared, the drive system is disconnected from sleeve 250 and it can be
normally
shifted with a conventional shifting tool.
Providing the drive system has not failed, shear screw 258 remains intact and
securely binds sleeve 250 to drive sleeve 260 which moves longitudinally up
and
downhole, pursuant to the movements of an actuator system more thoroughly
discussed
below. Longitudinal movement of inner sleeve drive sleeve 260 is limited by
shoulder
262, at the uphole end thereof, impacting against stop 264 located on choke
connector
sleeve 218 and is bounded at the downhole end thereof by sleeve end surface
266 which
abuts shoulder 269 when the sleeve 250 is at its downhole most position. Snap
ring 268
maintains seal 270 in the desired position. Inner sleeve drive sleeve 260
extends uphole
to a threaded engagement 274 with inner sleeve drive screw 272. It should be
noted that
preferably inner sleeve drive screw 272 is a spur gear arrangement on its O.D.
surface
and a threaded arrangement on its inner surface. The threads mate to O.D.
threads on
the inner sleeve drive sleeve 260. Thrust bearings 276 are provided on either
side of
CA 02450223 2004-09-02
-16-
inner sleeve drive screw 272 to more efficiently transfer power to drive
sleeve 260.
This is obtained by reduced friction due to the thrust bearings. Several idler
gears are
provided in the drive system one of which is visible in FIGURE 17 and is
indicated as
numeral 278.
Referring to FIGURE 22, a schematic perspective view of the drive system of
the invention will provide a better understanding to those of skill in the art
regarding
how the system is driven. Idler gears are indicated collectively as 278. The
solenoid is
identified by numeral 242 with solenoid gear 279, and the drive motor is 244.
The inner
sleeve drive screw 272 is closer to the motor arrangement and choke drive
screw 228 is
further away. Choke drive shaft 230 is also illustrated. The inner sleeve
drive gear is
illustrated as 280. FIGURE 22 in conjunction with the foregoing and FIGURES 17-
21
provide the skilled artisan with an excellent understanding of the invention.
The solenoid of the invention operates in a manner very similar to that of an
automobile solenoid and moves to engage one drive gear 280 or in order to
drive the
inner sleeve 272 or the choke sleeve 228 in the gear train described and
illustrated.
Power is fed to the solenoid and motor through the motor housing 282 by
conduit 284 which houses connector 281 such as a Kemlon* connector, known to
the art,
said conduit leading to electronics housing area 286 which is hermetically
sealed by
electronics housing cover 288 threadedly connected at 290 to motor housing 282
and
includes seal 292 to prevent wellbore fluids from contaminating the
electronics which
may include downhole processors, sensors and power sources. As discussed
earlier,
power may come from the surface or from downhole sources.
As in the previous embodiment, the motor and solenoid are most preferably
surrounded in pressure compensated dielectric fluid. The pressure compensation
device
are as was discussed previously. The fluid in this embodiment exists in area
294 and is
sealed from surrounding fluids by seal 296 held in place by snap ring 298.
Referring to FIGURES 23-27, a seal nose sleeve choke mechanism of the
invention is disclosed. The device employs a dual operation concept which
allows for
increased longevity in the useful life of the tool. Beginning at the downhole
end of the
tool in FIGURE 27, a lower sub 300 is threadedly connected to a ported housing
302. It
should be noted that the lower sub contains a stop shoulder 304 which is
employed only
*tirade-mark
CA 02450223 2003-12-08
- 17-
in the event of an electronics or motor drive failure or other failure in the
seal nose of the
device. More specifically, dog retaining sleeve 306 will abut against shoulder
304 in the
event the shear release of the invention is employed. In the event of a
failure requiring
the shear release to be employed, snap ring 308 is provided which will lock
into groove
310 of ported housing 302 to maintain dog retaining sleeve 306 in the downhole
position should such mechanical operation be required. The dog retaining
sleeve 306 is
threadedly connected to downstop 312 which communicates with inner sleeve 314.
It
should be noted that in normal operation, dog retaining sleeve 306 is fixedly
connected
to ported housing 302 via dog 316 to prevent relative movement between the two
sleeves. Providing electronic and/or automatic operation of the choke
mechanism of the
invention is functioning properly, no relative movement between the dog
retaining
sleeve 306 and ported housing 302 is necessary or desirable.
It should be noted that the shear out sleeve 318 is exactly the same as the
shear
out sleeve discussed previously and, therefore, will not be discussed in
detail here other
than to list numerically the parts thereof. Sleeve 318 includes snap ring 320
and snap
ring groove 322 as well as a set slot 324 which enables a'technician or
machine during
assembly of the tool to press snap ring 320 into the sleeve 318. Shear screw
326,
(obviously most preferably a plurality of shear screws 326) maintains the
shear out
sleeve 318 in the engaged position until a shifting tool is brought to bear
against shifting
profile 328 whereby shear screw 326 is sheared and the shear sleeve 318 is
shifted
uphole to release dog 316.
Moving uphole into FIGURE 25, and in the normal (not shear released)
operation of the tool, ported housing 302 includes seal 330 and defuser ring
332 which
operate the seal fluid flow through port 334 and prevent seepage during
periods when
such flow is not desired.
Inner sleeve 314 includes nose 336 which extends into annular groove 340 of
downstop 312. This provides a metal to metal seal to choke off flow through
port 334.
It should also be noted that in order to reduce the chances of washout of
seals 330 or
flow cutting thereof, annular recess 338 is provided in nose 336. This allows
for a
reduced flow rate during opening of inner sleeve 314 to reduce wear on seal
330. Inner
sleeve 314 further includes port 342 which is employed in the event of loss of
nose 336
CA 02450223 2003-12-08
-18-
or a failure of the actuation mechanism. This will be discussed in more detail
hereunder.
Inner sleeve 314 extends uphole and is illustrated as joined in a threaded
connection to
upper inner sleeve 352 which provides shifting profiles 354 and 356 for uphole
shi$ing
and downhole shifting, respectively in the event of a catastrophic occurrence
with
respect to the inner sleeve itself or the actuation mechanism. Lower sleeve
314 and
upper sleeve 352 in combination are secured to drive sleeve 360 by dogs 362
which are
maintained in the engaged position by shear out sleeve 364. This shear out
sleeve is
identical to that described earlier and a balance of the operative elements of
shear out
sleeve 364 are numerated identically to shear out sleeve 318. Thus, shear out
sleeve 364
includes snap ring 320, groove 322, set slot 324 and shear screw 326 as well
as shifting
profile 328. Drive sleeve 360 is threaded on its O.D. at at least the uphole
most portion
thereof wherein drive sleeve 360 is engaged with a drive screw 366. In order
to transfer
power more effectively, thrust bearings 368 are employed and are maintained in
their
desired positions by bearing retainers 370. Drive force is transferred to
drive screw 366
through drive shaft 372 which is supported at its downhole end by bearings 374
and
includes a spur gear arrangement 376 at the downhole end thereof which is
complimentary to a spur gear arrangement on the O.D. of drive screw 366. From
drive
shaft 372 uphole, the nose seal drive mechanism is identical to the dependent
sleeve
choke mechanism and therefore, is not illustrated or described in detail at
this point.
In operation, the nose seal choke mechanism provides several modes of
operation. Initially and preferentially, the electronics housing (not shown)
includes
downhole processors and power conduits or power supplies to determine through
preprogrammed instructions or based upon input from sensors such as linear
potentiometers, linear voltage display transducers, resolvers or synchros as
well as flow
sensors, pressure sensors, temperature sensors and other sensors downhole
whether the
flow should be increased or decreased. Upon such determination, the
electronics of the
device will cause the motor to turn the drive shaft in the desired direction
to either move
the nose seal uphole or downhole thus opening or closing ports 334 to the
desired extent.
Since nose 336 is either composed of or coated with a hard substance such as
tungsten
carbide, longevity of the nose should be substantial. However, in the event
that the nose
should become dislodged or worn away, the shear out sleeves 364 and 318 can be
CA 02450223 2003-12-08
-19-
sheared as described above by a conventional shearing tool to allow the
downstop and
dog retainers sleeves to slide downhole thereby allowing the inner sleeve to
slide
downhole exposing previously unused port 342 to port 334. After such
occurrence the
inner sleeve 314 can be actuated mechanically in a conventional manner with a
shifting
tool bearing on shifting profiles 354 or 356 to align or misalign port 342 or
port 334 to
varying degrees.
In another mode of operation, only shear out sleeve 364 would be removed
which would disconnect a malfunctioning motor drive system from the inner
sleeve and
allow the shifting tool to operate the nose seal in the originally intended
manner. This
allows the operator of the well to shift the nose seal choke mechanism
mechanically
with a shifting tool for an extended period of time even after failure of the
drive
actuation system. Moreover, if over time, in this mode of operation, the nose
seal is
worn away, the operator can shear the shear sleeve 318 and gain an entirely
new method
of operation of the tool by allowing port 342 to align with port 334. Thus
longevity of
the tool is significant. The shear out possibilities with this tool helps
prevent the need
for removing the tool from its downhole position for an extended period of
time.
In the helical key choke mechanism embodiment of the invention, referring to
FIGURES 28-36, a very similar drive mechanism is provided as those described
hereinabove, however the flow controlling features are distinct. More
specifically, the
invention contains an upper key body and lower key body having helical grooves
therein
and being adapted to receive removable keys which when extended into a helical
groove, choke flow through the tool. In the most preferred embodiment, the
choking
position of the tool moves keys from the upper section and lower section
toward one
another and this action is created by a single moving sleeve. The sleeve moves
downhole to close the helical flow areas and forces the upper keys downhole
with it
while it turns a spur gear at the downhole end which forces the lower keys
uphole while
the sleeve is moving downhole.
Beginning with the downhole end of the tool, at FIGURE 34, lower sub 400 is
threadedly connected to the lower key body 420 and outer housing 404. Outer
housing
404 contains a plurality of lower ports 406 which allow fluid to flow into
lower flow
area 408. The outer housing also includes upper ports 410 which allow fluid to
flow
CA 02450223 2003-12-08
-20-
into upper flow area 412. Flow areas 408 and 412 are communicatively connected
to
the helical flow paths 416 and 418 illustrated in FIGURE 35.
Radially inwardly of outer housing 404 are disposed lower key body 420 and
upper key body 422 which are visible both in section view in FIGURES 30-32 and
in
plan view in FIGURE 35. These key bodies provide the helical flow paths to
enable the
choking action desired by the invention by moving the lower keys 424 and upper
keys
426. Preventing flow into undesired areas are seals 428 which maintain
position by seal
retainer 430. Upward movement of sleeve 432 opens flow through the helical
flow path
416 and 418 by moving keys 424 and 426 increasing the flow area at the keys.
Movement of sleeve 432 also moves ports 429 in alignment with ports 431 in the
upper
key body 418. Fluid from the helical flow paths 416 and 418 enter a plenurn
chamber
433 and commingle reducing their kinetic energy. Fluid is then redirected
through the
ports 429 in sleeve 432 into the tubing. Continuing to concentrate on FIGURES
30-33,
inner sleeve 432 extends through each of the identified drawings to actuate
both lower
keys 424 and upper keys 426. A longitudinal movement of inner sleeve 432 moves
upper keys 426 through the urging on projection 434 of inner sleeve 432.
Projection
434 is received in slot 436 of inner sleeve 432 to provide positive engagement
thereof.
Lower key 424 is likewise moved by inner sleeve 432 but in a direction
opposite that of
upper keys 426. The movement is proportional in magnitude but opposite in
direction.
The action described is created by providing spur teeth 438 on the O.D. of
inner sleeve
432 at the appropriate location to engage spur gear 440 which translates
energy inputted
by the inner sleeve 432 to lower key 424 through rack teeth 442 on the LD. of
keys 424.
The helix key choke mechanism embodiment of the invention is illustrated in
the
drawings in the closed, fully choked position; as will be appreciated by one
of ordinary
skill in the art, from the lack of a gap at the location indicated as 446 for
the upper keys
and 448 for the lower keys. In drawing FIGURES 29 and 30 dog 450 is readily
apparent
which is held in place by shear sleeve 452 which has been described
hereinabove and
will not be described now. Dog 450 locks inner sleeve 432 to drive sleeve 454
which is
housed in connector housing 456. Drive sleeve 454 extends uphole into
communication
with drive screw 458 which employs thrust bearings 460 and bearing retainers
462 as
discussed hereinabove. In the event of a failure of the motor actuation of
this tool, shear
CA 02450223 2003-12-08
-21 -
sleeve 452 will be utilized as above described to release inner sleeve 432
from drive
sleeve 454 whereafter profiles 470 at the uphole end of the tool and 472 at
the lower end
of the tool may be employed via a conventional shifting tool to actuate the
helix key
choke mechanism of the invention.
Referring to FIGURES 37-41, the spiral choke mechanism embodiment of the
invention is illustrated the spiral choke mechanism includes a housing having
a
longitudinal port and a rotatable spiral choke within the housing such that
flow can be
stopped or choked to a desired extent. The spiral choking insert includes a
longitudinal
port to allow flow to the LD. of the tubing.
Beginning from the downhole end of the tool , at FIGURE 41 and moving uphole
(or backward in drawing figure numbers) lower sub S00 extends uphole to mate
with
ported housing 502 which provides a longitudinal port illustrated in FIGURE
39a said
port being indicated as 504. The ported housing extends uphole to terminate at
motor
housing 530. Other features of ported housing 502 are seals 506 which are
disposed on
uphole and downhole ends of the flow choking section of inner sleeve 512.
Ported
housing 502 further includes snap ring receiving groove 508 which will be
employed
only if the drive mechanisms of the tool fails. This will be discussed
hereunder.
Radially inwardly of ported housing 502 is inner sleeve 512 as mentioned
above.
Initially 512 is best viewed in the cross section view of FIGURE 39a which
provides an
understanding to one of skill in the art of the gradually increasing flow area
between
ported housing 502 and inner sleeve S 12. As one of skill in the art will
understand, as
sleeve 512 is rotated in the counterclockwise direction flow through port 504
is
increased. When the choke sleeve 512 is in the closed position, seals 514 are
positioned
on either side of port 504 and prevent any flow between the well annulus and
the tubing.
When the choke is open flow will be carried through flow area 516 until the
flow
reaches port 518 and flows into the tubing itself.
Sleeve S 12 is notably actuated by motor 532 which drives upper sleeve 520
through ring gear profile 522 in order to create smooth power flow. Thrust
bearings 524
are located as indicated and are all retained by thrust bearing retainer 526.
The motor is
surrounded as in previous embodiments by dielectric fluid occupying the space
indicated
as 528 and sealed from wellbore fluid by seal 534 which is held in place by
snap ring
CA 02450223 2003-12-08
-22-
536. Fluid compensators are also preferably employed. Motor housing 530
provides
power conduit 538 which connects to electronics area 540 covered by
electronics
housing cover 542.
Refernng to FIGURE 38 the dog retainer 544, it will be understood, rotates
easily due to reduced friction rotatably due to thrust bearings 524 while
still maintaining
the inner sleeve 512 in communication with the motor drive.
In the event of a failure of the invention, provision is made for closing off
a
choke mechanism but not for operating the choke mechanism subsequent to
shearing.
Upon the occurrence of such a failure shear sleeve 546 is actuated as
described in more
detail with respect to the embodiments above. Subsequent to dog 548
disengaging from
dog retainer 544 the shifting tool (not shown) is employed upon shifting
profile 550 to
force inner sleeve 512 downhole misaligning a spiral choking element of that
sleeve
from the longitudinal port 504 to permanently close the flow control device.
In order to
ensure that the device will not self open, snap ring 552, upon moving of
sleeve 512
downhole, will expand into snap ring receiving groove 508 and will prevent
relative
movement of sleeve 512 and ported housing 502.
In a final embodiment of the invention, an orifice choke mechanism is
disclosed.
Refernng to FIGURES 42-46, the orifice choke is illustrated in cross-section
which
embodiment provides a plurality of orifices constructed of an erosion
resistant material
and which can be exposed from the inside of the tubing by an inner sleeve.
This tool as
in the foregoing embodiments is preferably actuated by a downhole motor drive
system
including an electronics package having a processor and sensor capability.
Refernng
directly to the drawings and the downhole end of the tool (FIGURE 46) a lower
sub 600
extends uphole to threadedly mate with orifice housing 602. It should be noted
that
lower sub 600 provides stacked radial recesses on the LD. thereof to receive
elements of
the invention. The first recess allows seal cover 604 to slide along the LD.
of lower sub
600 while not restricting the overall LD. of the tubing string. The second
recess accepts
spring 606 which biases seal cover 604 to the uphole position when inner
sleeve 608 is
moved uphole to expose any number of the plurality of orifices 610. The
purpose of
seal cover 604 and spring 606 is to maintain uphole end 612 of seal cover 604
in contact
with shifting profile 614 of inner sleeve 608 so that when inner sleeve 608
moves
CA 02450223 2003-12-08
- 23 -
uphole due to the impetus of either the motor drive system of the invention or
the
backup conventional shifting tool system, the seal cover 604 will cover seal
616 and
prevent flow cutting thereof. The operative area of the flow control device
further
includes a screen 618 to protect the plurality of orifices during run in the
hole and to
prevent debris from collecting at the orifices and reducing the flow thereof.
As one of
skill in the art will appreciate each orifice is extended beyond flush with
orifice housing
602. This is to provide room for erosion of the orifices without causing any
damage to
the device. It should also be noted that the orifices are squared off to
provide a pressure
drop therethrough thus enhancing the operability of the tool. The orifices
themselves are
most preferably constructed of tungsten carbide or other similar highly
erosion resistant
material to provide for longevity of the tool.
Orifice housing 602 includes seals 616, noted above, and seal 620 to provide
effective seal of the device and stop flow should such action be determined
necessary or
desirable. It is, otherwise, noted that numeral 622 points out that there is a
gap between
the inner sleeve 608 and the orifice housing 602 on the order of one to
several
thousandths of an inch. This provides for a very small amount of flow from the
uphole
ports when only lower hole ports are exposed by uphole movement of the inner
sleeve
608. Orifice housing 602 is threadedly connected to housing connector 624
which is, in
turn, connected to a gear housing and uphole components. Radially inwardly of
housing
connector 624, one of skill in the art having been exposed to the foregoing
embodiments
will recognize drive sleeve 626 which is locked to inner sleeve 608 through
the inner
media are of dog 628 the dog is held in place with a Shear release sleeve
which has been
hereinbefore described and will not be described at this point. Drive sleeve
626 extends
upwardly to threadedly mesh with drive screw 630 in a manner hereinbefore
described.
Drive screw 630 also includes thrust bearing 632 and bearing retainers 634
which are
outwardly bounded by gear housing 636. Screw 630 is driven by drive shaft 638
and
motor 640. The motor transmits power through a spur gear 642 supported by
bearings
644 and a second gear 646 also supported by bearings 644. Power is supplied to
the
motor and downhole control exists in the same manner as previously described
with the
foregoing embodiments. In the event of a failure of the motor drive system of
the
invention, the shear out sleeve 648 is actuated releasing dog 628 from drive
sleeve 626
CA 02450223 2003-12-08
-24-
whereafter a conventional shifting tool is employed on shifting profile 650 or
614 to
open or close the choke mechanism respectively.
While preferred embodiments have been shown and described, various
modifications and substitutions may be made thereto without departing from the
spirit
and scope of the invention. Accordingly, it is to be understood that the
present invention
has been described by way of illustration and not limitation.
