Note: Descriptions are shown in the official language in which they were submitted.
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Wellbore Tool with Indexing Mechanism and Method
Priority Application
This application claims priority to US provisional application serial number
61/703,138,
filed September 19, 2012.
Field of the Invention
The invention relates to a wellbore tool with an indexing mechanism and
methods for
using the tool.
Background of the Invention
If a wellbore tool is positioned down hole in advance of its required
operation, the tool
must be actuated remotely. Indexing mechanisms may be useful where a tool is
intended
to be actuated through a number of positions.
For example, in some tools, indexing mechanisms are employed to actuate a tool
through
a number of inactive positions before it reaches an active position. For
example,
indexing mechanisms may be employed in wellbore tools for wellbore fluid
treatment
such as staged well treatment. In staged well treatment, a wellbore treatment
string is
deployed to create a plurality of isolated zones within a well. The wellbore
treatment
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string includes a plurality of openable ports that allow selected access to
each such
isolated zone. The treatment string is based on a tubing string and carries a
plurality of
packers that can be set in the hole to create isolated zones therebetween
about the annulus
of the tubing string. Between at least selected packers, there are openable
ports through
the tubing string. The ports are selectively openable and include a sleeve
thereover with
a sealable seat formed in the inner diameter of the sleeve. By launching a
ball, the ball
can seal against the seat and pressure can be increased behind the ball to
drive the sleeve
through the tubing string to open the port in one zone. The seat in each
sleeve can be
formed to accept a ball of a selected diameter but to allow balls of lower
diameters to
pass.
Unfortunately, due to size limitations with respect to the inner diameter of
wellbore
tubulars (i.e. due to the inner diameter of the well), such wellbore treatment
systems may
tend to be limited in the number of zones that may be accessed. For example,
if the well
diameter dictates that the largest sleeve in a well can at most accept a 31/4"
ball, then the
well treatment string will generally be limited to approximately eleven
sleeves and,
therefore, can treat in only eleven stages.
A tool with an indexing mechanism may permit a ball of one size to actuate a
number of
tools and thus permit a string to be employed with a greater number of zones.
Summary of the Invention
In accordance with an aspect of the present invention, there is provided a
wellbore tool
comprising: a tubular housing including an upper end, a lower end, and a wall
defined
between an inner surface and an outer surface; a tool mechanism capable of
being
reconfigured from a first inactive position to an active position; an indexing
mechanism
for reconfiguring the tool mechanism, the indexing mechanism including an
indexing
sleeve including an inner bore, the indexing sleeve biased to move axially
along the inner
surface, and an inner sleeve positioned within the inner bore, the inner
sleeve having an
axial bore extending therethrough and a wall thickness, and a lever having
first and
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second ends, the lever pivotally connected to the inner sleeve at a fulcrum
and being
pivotal through a slot in the inner sleeve to protrude at the second end into
the axial bore,
while the first end engages and stops axial movement of the indexing sleeve;
and an
actuator for passing through the axial bore and contacting the second end to
drive the first
end out of engagement with the indexing sleeve, thereby permitting axial
movement of
the indexing sleeve to move the tool mechanism from the first inactive
position toward
the active position.
In accordance with another aspect of the present invention, there is provided
a wellbore
sliding sleeve sub comprising: a tubular housing including an upper end, a
lower end and
a wall defined between an inner surface and an outer surface; a fluid port
through the wall
of the tubular housing; an inner sleeve having an axial bore and installed
substantially
concentrically in the tubular housing, the inner sleeve being axially
slideable in the
tubular housing at least from a first position covering the fluid port to a
second position
exposing the fluid port to fluid flow therethrough; a ball seat on the inner
sleeve
including a plurality of levers connected to the inner sleeve about a
circumference of the
wall, each of the plurality of levers including a first end, a second end and
a pivotal
connection to the inner sleeve between the first end and the second end, and
each lever
capable protruding at the second end into the axial bore while the first end
extends
radially outwardly of the inner sleeve, the ball seat being configurable from
(i) an
inactive position wherein the plurality of levers is capable of pivoting to
collapse and
allow passage of an actuator through the axial bore to (ii) an active
position, wherein the
plurality of levers is fixed against pivotal movement and remains protruding
into the axial
bore to catch a sleeve shifting device; and an indexing sleeve positioned
substantially
concentrically between the inner sleeve and the tubular housing, the indexing
sleeve
controlling the configuration of the ball seat between the active position and
the inactive
position, wherein the indexing sleeve is biased for axial movement along the
tubular
housing between a first position allowing collapsing of the plurality of
levers and a
second position supporting the plurality of levers in the active position.
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In accordance with another aspect of the present invention, there is provided
a method for
actuating a downhole tool to an active condition, the method comprising:
passing an
actuator through a ball seat in the downhole tool to permit incremental
movement of an
indexing sleeve past the ball seat until the indexing sleeve moves to a final
position
wherein the ball seat is held by the indexing sleeve against collapsing,
thereby
configuring the ball seat in an active position to catch a sleeve shifting
device conveyed
through the string.
It is to be understood that other aspects of the present invention will become
readily
apparent to those skilled in the art from the following detailed description,
wherein
various embodiments of the invention are shown and described by way of
illustration. As
will be realized, the invention is capable for other and different embodiments
and its
several details are capable of modification in various other respects, all
without departing
from the spirit and scope of the present invention. Accordingly the drawings
and detailed
description are to be regarded as illustrative in nature and not as
restrictive.
Brief Description of the Drawings
Referring to the drawings, several aspects of the present invention are
illustrated by way
of example, and not by way of limitation, in detail in the figures, wherein:
Figures 1 to 4 are views of a wellbore tool with an indexing mechanism,
wherein:
Figure 1 is a sectional view through a wellbore tool in a position ready to be
moved through an indexing cycle;
Figure 2 is an isometric view of an inner sleeve of the wellbore tool of
Figure 1;
Figures 3A, 3B, 3C and 3D, sometimes referred to collectively as Figures 3,
are
enlarged sectional views of the tool following from Figure 1 showing
sequential
stages in the indexing cycle; and
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Figure 4 is a sectional view through the wellbore tool following after Figure
3D,
in an active position after all indexing cycles are completed;
Figure 5 is a sectional view through a wellbore having positioned therein a
fluid
treatment assembly and showing another method according to the present
invention; and
Figures 6A to 6F, sometimes referred to collectively as Figures 6, are a
series of
schematic sectional views through a wellbore having positioned therein a fluid
treatment
assembly showing a method according to the present invention.
Detailed Description of Various Embodiments
The description that follows and the embodiments described therein, are
provided by way
of illustration of an example, or examples, of particular embodiments of the
principles of
various aspects of the present invention. These examples are provided for the
purposes of
explanation, and not of limitation, of those principles and of the invention
in its various
aspects. In the description, similar parts are marked throughout the
specification and the
drawings with the same respective reference numerals. The drawings are not
necessarily
to scale and in some instances proportions may have been exaggerated in order
more
clearly to depict certain features.
A wellbore tool that is actuable through a plurality of positions may include
a tubular
housing including an upper end, a lower end, and a wall defined between an
inner surface
and an outer surface; a tool mechanism capable of being reconfigured from a
first
inactive position to an active position; an indexing mechanism for
reconfiguring the tool
mechanism, the indexing mechanism including an indexing sleeve including an
inner
bore, the indexing sleeve biased to move axially along the inner surface, and
an inner
sleeve positioned within the inner bore, the inner sleeve having an axial bore
extending
therethrough and a wall thickness, and a lever having first and second ends,
the lever
pivotally connected to the inner sleeve at a fulcrum and being pivotal through
a slot in the
inner sleeve to protrude at the second end into the axial bore, while the
first end engages
and stops axial movement of the indexing sleeve; and an actuator for passing
through the
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axial bore and contacting the second end to drive the first end out of
engagement with the
indexing sleeve, thereby permitting axial movement of the indexing sleeve to
move the
tool mechanism from the first inactive position toward the active position.
In operation, the tool may be employed in a wellbore operation wherein the
tool is
positioned in a well with the housing in a selected position, a force may be
applied to an
indexing mechanism of the tool to drive a tool mechanism through a plurality
of
positions, the applied force driving may be via an actuator passing through
the tool while
it is installed downhole. The actuator may be launched from surface. Passing
the
actuator through the indexing mechanism permits incremental movement of an
indexing
sleeve to take the indexing mechanism through an indexing cycle until the
indexing
sleeve moves to a final position wherein the tool is brought into an active
position. The
indexing mechanism includes a component protruding into the inner bore of the
tool such
that it can receive the applied force of the actuator passing therethrough.
The indexing
mechanism may include a lever. In one embodiment, the lever forms a ball seat
that in
the final position is held by the indexing sleeve against collapsing. In this
position, it is
active to catch a sleeve-shifting device.
Generally, a wellbore tool often has a tubular housing, which, having a
tubular form, can
pass readily through the wellbore as drilled. Also, tubular forms can be
connected by
threading into assembled tools or strings deployable into a well. The tool may
be run into
a well for temporary use or may be installed in a well for longer term use or
reuse.
The wellbore tool may be a packer, an anchor, a sliding sleeve tool, etc. The
form of the
wellbore tool is determined by its tool mechanism. For example, a packer
includes a tool
mechanism including a packing mechanism with at least a set and an unset
position, the
packing mechanism may include an annular packing element, one or more
compression
rings, etc. The tool mechanism of an anchor includes an anchoring mechanism
including
at least a set and an unset position, the anchoring mechanism may include a
plurality of
slips, a slip expander, etc. A tool mechanism of a sliding sleeve tool
includes a port and a
sliding sleeve moveable to open and close the port. The sliding sleeve tool
has at least a
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closed port position and an open port position. As another example, another
sliding
sleeve tool has a tool mechanism including a port, a sliding sleeve moveable
to open and
close the port and a seat for the sliding sleeve to allow plug actuation of
the sliding sleeve
and in such an embodiment, the sliding sleeve valve may include at least an
activated seat
position ready to catch a plug (such as a ball or other plug form that is
sized to seal in the
seat) and an inactive seat position wherein either the seat has not yet formed
or the seat is
in place but is collapsible such that the ball may pass through the seat.
The form of the tool determines the method that is carried out by the tool.
For example,
the method may include forming an annular seal, anchoring a tool, opening a
port, etc.
The tools and methods of the present invention can be used in various borehole
conditions including open holes, cased holes, vertical holes, horizontal
holes, straight
holes or deviated holes.
With reference to Figures 1 to 4, an example of a wellbore sliding sleeve tool
10 is shown
that is modified by the passage therethrough of one or more actuators 11 that
eventually
configure an inner sleeve 12 of the tool to be drivable to an open position by
a sleeve
shifting device 14. While inner sleeve 12 can originally be configured not to
be
driveable, it can be modified by the passage of one or more actuators to be
driveable. In
particular, by passage of actuators 11, sleeve 12 can be configured such that
during the
subsequent passage of a sleeve shifting device 14, sleeve 12 may be actuated
by the
sleeve shifting device to shift open. The reconfiguration of the sleeve to be
driven by a
sleeve shifting device in this embodiment, includes the formation of a seat 16
in non-
collapsible form after one or more actuations of the tool, as controlled by an
indexing
mechanism. For example, in one embodiment, the indexing mechanism may allow
the
tool to be advanced through a plurality of positions prior to placement in a
position
wherein the valve seat is actually configured in a non-collapsible way. As
shown in the
Figures, one or more actuators may each cycle the components of the indexing
mechanism to advance one position, through one or more inactive (also termed
passive)
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positions, before finally moving into an active position to form the final,
non-collapsible
valve seat 16.
In the drawings, Figure 1 shows tool 10 in a run in position just about to be
cycled by
actuator 11 (in this embodiment actuator 11 is in the form of a ball); Figures
3A, 3B, 3C
and 3D are sequential, enlarged, sectional views showing the tool moving
through the
stages of an indexing cycle, as driven by the same actuator 11; and Figure 4
shows tool
in an active position, with sleeve 12 reconfigured such that seat 16 is formed
in a non-
collapsible way and inner sleeve 12 has been driven by a sleeve shifting
device 14
(shown in phantom so as not to obstruct illustration).
The illustrated sliding sleeve tool includes a tubular housing 20 including an
upper end
20a, a lower end 20b, an inner surface 20c defining an inner bore and an outer
surface
20d. Although not shown, the sliding sleeve tool, may be formed as a sub with
its tubular
housing 20 having ends 20a, 20b threaded or otherwise formed such that it may
be
connected into a wellbore tubular string. The housing defines a long axis x
extending
through its ends 20a, 20b.
The sliding sleeve tool includes one or more ports 22 through the wall of the
tubular
housing where the port, when opened, provides access between the inner bore
and outer
surface 20d. The open and closed condition of port 22 is determined by sleeve
12. The
sleeve is axially moveable in the tubular housing between a position overlying
and
closing port 22 (Figure 1) and a position at least partially retracted from,
and therefore
opening, port 22 (Figure 5).
Sleeve 12 includes an inner bore 12a and an outer surface 12b. The sleeve
includes seat
16 in bore 12a. Seat 16 is capable of being configured through a plurality of
positions
including one or more inactive positions and an active position. In the
inactive positions
(Figures 1 to 3D) seat 16 is collapsible and allows any actuator, such as
actuator 11, that
lands therein to pass. In the active position (Figure 4), seat 16 is
configured in a non-
collapsible way and is capable of catching and retaining sleeve shifting
device 14. In
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particular, seat 16 in the active position cannot collapse and sleeve shifting
device 14 that
is sized to be larger than the uncollapsed ID of the seat will be caught in
the seat and
cannot pass through. Sleeve shifting device 14, therefore, lands in and
creates a
substantial seal with the seat. Thus, an axially directed force can be applied
to sleeve 12
by fluid pressure through a piston effect created by device 14 in seat 16. The
applied
pressure can overcome any holding devices such as shear pins 17 and drives the
sleeve to
open.
Sleeve shifting device 14 and actuators 11 may be plugs such as balls, as
shown, or other
plug forms like darts, etc., that are launchable from surface and sized to
have an outer
diameter greater than the uncollapsed ID of seat 16. In this illustrated
embodiment, both
sleeve shifting device 14 and actuator 11 are balls. As shown here, actuator
11 may
actually be identical to sleeve shifting device 14. However, the seat
collapses when it is
in an inactive configuration to let actuator 11 pass, while seat 16, when
active, is
configured to retain and create a substantial seal with sleeve shifting device
14, which
explains the differing operations of the actuator and the sleeve shifting
device. It is a
benefit of the tool to be able to use the same size device 11, 14 to actuate a
number of
tools in the string.
The indexing mechanism includes one or more levers 24 and an indexing sleeve
26. The
levers 24 protrude into the inner bore of sleeve 12 and creates a diameter
restriction to
sense the passage of an actuator. Herein, levers 24 also form seat 16 in the
active
position.
Levers 24 each include an upper end 24a and a lower end 24b and are each a
primary
lever. Being a primary lever, load on one end causes movement of the other
end.
Levers 24 are each connected to sleeve 12 by a fulcrum pin 28, here in the
form of
shoulder bolts secured by end nuts 28a. Each fulcrum pin 28 connects its lever
24 such
that the lever pivots about an axis y which extends the length of the pin, is
positioned in
the thickness of the wall of sleeve 12 and is substantially orthogonal to axis
x. Each lever
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24 is connected by pin 28 in a slot 30 formed through the wall of sleeve 12
such that,
when pivoting, the ends 24a, 24b can protrude into inner bore 12a and beyond
outer
surface 12b. Levers 24 are exposed in sleeve inner bore 12a and can be acted
upon by
structures passing through the bore.
The levers are spaced apart about a circumference of sleeve 12 and effectively
create a
ring coaxial with sleeve 12.
Levers 24 may each have an upper rear protrusion 24a and a lower rear
protrusion 24b'.
In addition, the levers may each have a lower front protrusion 24b".
Protrusions 24a',
24b, 24b" extend out beyond the surrounding lever surface to increase the
thickness of
the levers at their ends and, for example, to extend the reach of the levers
at their ends.
These protrusions may be shaped to facilitate operation of the levers.
While the illustrated tool includes four levers 24, more or fewer levers can
be employed.
However, there is some benefit in providing a plurality of levers
substantially equally
spaced apart about the sleeve's circumference so that any forces on the levers
may be
balanced about the circumference and there may be a back up to overcome a
failure of
one lever, since each lever may operate independently.
Indexing sleeve 26 is positioned concentrically between tubular housing 20 and
sleeve
12, Sleeve 12 is positioned inwardly of the inner wall 26a of the indexing
sleeve. Since
the indexing sleeve encircles sleeve 12, the indexing sleeve 26 has a normal
diameter D
across its inner wall 26a that is greater than the outer diameter of the
sleeve's outer
surface 12b. The normal diameter may be just slightly greater than the outer
diameter of
the outer surface of sleeve 12, Indexing sleeve 26 includes a plurality of
recesses 32 on
its inner wall 26a. The recesses 32 are axially spaced apart along the wall of
indexing
sleeve with raised areas 33 therebetween separating the recesses. The raised
areas have a
diameter less than the recess diameter RD and greater than or equal to the
normal
diameter D. In the illustrated embodiment, recesses 32 are annular grooves
separated by
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the raised areas and raised areas 33 are also annularly formed, such that the
inner surface
of the indexing sleeve has a ribbed surface contour with uniformly shaped,
repeating ribs.
An end, support wall portion 34 of the indexing sleeve is devoid of recesses
and is raised
such that it defines an inner diameter less than the recess diameter RD and
greater than or
equal to the normal diameter D. The support wall portion is positioned at an
end of the
recesses. In this embodiment, the support wall is positioned adjacent the
uppermost
recess.
Indexing sleeve 26 is positioned in a space between tubular housing 20 and
sleeve 12.
The space is an annular recess between upper wall 40 and lower wall 42.
Indexing sleeve
26 is biased to move axially along the annular recess, when it is free to do
so. In the
illustrated embodiment, sleeve 26 is biased to move toward lower wall 42. A
spring 44
may be positioned between sleeve 26 and upper wall 40 to bias the sleeve
toward lower
wall 42.
Indexing sleeve 26 works with levers 24 to index the tool through a number of
cycles of
inactive positions before reaching the active position. Levers 24 normally
bear against
indexing sleeve 26. In particular, levers 24 normally extend through slots 30
to bear at
their upper ends against inner wall 26a. When a lever 24 bears at upper end
against
indexing sleeve 26, the opposite end of the lever protrudes from slot 30 into
inner bore
12a of sleeve 12. The indexing mechanism operation depends on the interaction
of one
end of each lever 24 against sleeve 26, while at the same time the opposite
end of each
lever protrudes into inner bore 12a of sleeve. The protrusion of the opposite
ends of the
levers into the sleeve's inner bore, allows the levers to be acted upon by a
passing
actuator.
During indexing, the levers are moved through a plurality of positions and as
the levers
are moved, the indexing sleeve, being constantly under a biasing force, moves
incrementally axially along the annular space.
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In the starting position (Figures 1 and 3A), levers 24 bear at their upper
ends against
sleeve 26. In particular, upper ends 24a are engaged in one of the recesses 32
on the
inner wall of the indexing sleeve, Upper ends 24a, being engaged in one of the
recesses
32, hold the indexing sleeve against the bias of spring and prevent indexing
sleeve 26
from moving down, In this starting position, while upper ends 24a engage the
indexing
sleeve, lower ends 24b protrude into inner bore 12a and create a constriction
less than the
inner diameter of the sleeve and less than the diameter of an actuator 11
selected to work
with those levers.
In a second position (Figure 3C) of the indexing cycle, the levers have been
rotated,
arrows R (Figure 3B), about their fulcrums such that lower ends 24b bear
against
indexing sleeve 26. Levers 24 may be moved from the starting position to this
second
position by an actuator bearing against the levers. When levers 24 are
rotated, as by the
actuator passing over the levers, upper ends 24a are pulled out of engagement
with sleeve
26 and spring 44 is capable of moving sleeve 26 until lower ends 24b bear
against
indexing sleeve 26.
During indexing through the positions, the levers are moved, arrows R, between
the
starting position (Figure 3A) and the second position (Figure 3C). As noted,
this pivoting
movement is driven by an actuator 11 that has a diameter greater than the
constricted
diameter of the levers moving against and past the levers. An actuator moving
downhole,
arrow A, for example after being launched from above, lands against the
protruding
lower ends 24b of the levers and since the ends form a constriction less than
the diameter
of the actuator, the actuator pivots the levers to move past them, as shown in
the sequence
of Figures 3A-3C.
After passage of actuator 11, when the actuator clears the levers, the levers
immediately
return, arrows R2, from the second position to either (i) a next starting
position (Figure
3D), where upper ends 24a are again engaged against sleeve 26 to stop it, or
(ii) the
active position (Figure 4), where levers 24 are stopped from further rotation,
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In a next starting position, the ends 24a are placed into another recess and
the sleeve is
biased down to immediately engage protrusions 24a' against wall 34a. For
example, from
Figures 3A to 3D, it can be seen that ends 24a move from recess 321 to 3211.
If an end
24a hits against a raised area 33 during its pivotal movement along arrows R2,
lever 24
won't stop movement of the sleeve 26. However, sleeve 26 continues to move
down until
end 24a can enter a recess and then end 24a engages in the recess and stops
movement of
the sleeve.
Eventually, the active position is reached (Figure 4) where the levers are
supported
against support wall 34 of the indexing sleeve. In this active position,
levers 24 are
substantially stopped against rotation through slot 30 and they remain
protruding into
inner bore 12a to create a constriction which forms ball seat 16. Ball seat 16
has a
diameter less than that across inner wall 12a and less than the diameter of
sleeve shifting
device, which herein is ball 14. In the illustrated embodiment, lower ends 24b
form the
ball seat, but upper ends 24a could alternately form the ball seat, depending
on the shape
of support wall 34 and the shape of ends 24a, 24b.
When the tool is indexed from an inactive position to the active position, the
levers are
moved from the starting position, to the second position and then into the
active position.
The passage of an actuator 11 moves the levers from the starting position to
the second
position and, once the actuator passes, the levers then move from the second
position to
the active position.
In the inactive, starting position, levers 24 hold the indexing sleeve against
the bias in
spring 44 and prevent sleeve 26 from moving axially down. However, levers 24
may be
disengaged from the recess by passage of an actuator 11. Passage of an
actuator strikes
against lower ends 24b and causes the levers to rotate about their fulcrum pin
28. Since
the levers hold the sleeve from being biased by spring 44, disengagement of
the levers
from the indexing sleeve allows the sleeve to be moved down. When moving from
the
second position back to the starting position or to the active position, upper
ends 24a are
returned to a position against the indexing sleeve. Whether the indexing cycle
returns the
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tool to an inactive, starting position or moves the tool to the active
position is determined
by the structure of the indexing sleeve that has been moved by spring 44
behind the
levers. In particular, the levers may be engaged in another recess 32 or they
may be
positioned against the end support wall portion 34.
The number of times that a lever is capable of cycling before arriving at the
active
position depends on the number of recesses into which upper end 24a can engage
before
reaching the support wall 34: that is, the number of recesses between the
starting position
recess 321 (in which the upper ends are first installed before run in) and the
support wall
34. Thus, the number of axially spaced apart recesses 32 on sleeve 26 is at
least one plus
the number of inactive cycles through which the indexing system is intended to
pass
before reaching the active position. (i.e. the number of recesses required on
sleeve 26 is
the first one, in which the upper end of the lever is originally set, plus a
number of
recesses at least equal to the number of times that the tool is to be indexed
before
reaching the active position.) While, there may be more recesses than the
number of
times that the tool is intended to be indexed, the starting position of the
lever will be
selected as that recess below the total of the number of inactive cycles
through which the
indexing system is intended to pass before reaching the active position.
As noted, levers 24 normally bear at their upper ends against sleeve 26. The
levers may
each be biased, for example by a spring about fulcrum pin 28, to assume this
position.
Alternately, the shape of the levers and the indexing sleeve together with the
action of
spring 44, may be selected to urge the upper ends to bear against the sleeve.
For
example, lower rear protrusion 24b' can include a ramped upper surface 24bl"
shaped to
urge lever 24 to rotate along arrow R2. In particular, if lower rear
protrusion 24b' is
positioned in a recess on the sleeve and sleeve 26 is urged down by spring 44,
raised area
33 pushes against ramped upper surface 24b"' and drives lower rear protrusion
24b' out of
the recess (Figure 3C). This causes lever 24 to pivot, arrows R2, and bear at
upper end
24a against sleeve 26. If this form of biasing is used, the indexing sleeve
pushes against
the ramped upper surface. For example, further raised areas 33 may be required
on the
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indexing sleeve to push against surface 24b" and bias the lever, even if those
further
raised areas/recesses aren't used for engagement by upper end 24a. Thus, the
indexing
sleeve may include more recesses and raised areas than those used for
engagement by the
upper end of the lever, those additional recesses and raised areas being
between the lower
end of the indexing sleeve and the starting recess 321.
The upper rear protrusion 24a' and the recesses may be shaped to enhance the
engagement between them. For example, the upper rear protrusion 24a' and the
upper
walls 32a of the recesses may be angled with the upper rear protrusion 24a'
extending
upwardly and the upper wall 32a extending at an acute angle relative to the
base 32b of
the recess. Thus, when upper rear protrusion 24a' resides in a recess, the
upper wall
engages over the upper rear protrusion and upper rear protrusion 24a' can only
be
disengaged from recess by urging sleeve 26 upwardly to effectively lift the
upper wall off
the protrusion. Thus, to pull upper ends 24a out of a recess, enough force
must be
applied to pull upper rear protrusion 24a' against upper wall 32a and,
thereby, move
sleeve 26 upwardly against the bias in spring 44.
Support wall area 34 may have a form to support levers 24 in a position
forming a
constriction that is a non-collapsing seat. For example, while support wall 34
may take
various forms, in the illustrated embodiment, it has a diameter that forces
lower ends 24b
out into the inner bore of sleeve 12 and supports them in this position. Also
in the
illustrated embodiment, support wall 34 is spaced from recesses 32 by a large
groove 48.
Large groove 48 has a diameter about equal to recess diameter RD and allows
upper end
protrusion 24a' to be rotated toward sleeve 26 to allow lower end rear
protrusion 24b' to
be rotated into the inner bore of sleeve to clear recesses 32 on the sleeve.
Large groove
48 is axially long enough that the levers can rotate freely, until the
recesses 32 are
entirely pushed, by spring 44, past the lower ends of the levers. Thus,
sufficient space is
provided between recesses 32 and support wall 34 that only when lower end rear
protrusion 24b' is clear of the recesses, does support wall 34 come to
underlie the levers,
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Thus, in the illustrated embodiment, support wall area 34 is spaced from the
upper most
recess at least a distance equal to the length from protrusion 24a' to
protrusion 24b'.
In use, the tool is assembled with indexing sleeve 26 biased downwardly by
spring 44
and sleeve 26 held against the bias in spring by levers 24 engaged in a recess
in the
indexing sleeve. Thus, indexing sleeve 26 is biased to axially move down
relative to
levers 24, but can only do so when freed from engagement with the levers.
Upper end 24a of each lever is engaged in a selected recess of the indexing
sleeve. The
recess in which the upper end is engaged is the one below a number of recesses
equal to
the number of times the tool is to be cycled through inactive positions. For
example, with
reference to Figure 1, the tool requires five cycles through inactive
positions before
arriving at the active position and, thus, the lever upper end 24a is
initially installed, as
shown, at the 6th recess 321 from the upper end. While upper ends 24a are
engaged
against sleeve 26, the lower ends 24b protrude into the inner bore of sleeve
12.
Sleeve 12, on which the levers are pivotally installed, is held stationary in
the tool, as by
shear pins 17.
The tool is then run into the wellbore.
During wellbore operations, actuators 11 are launched from above, such as from
surface,
to at least drive the tool through its inactive cycles. The actuators pass
through the inner
bore of sleeve 12. The actuators may serve other purposes in the well, if
desired.
When an actuator 11 lands against ends 24b, the levers are rotated about their
fulcrums as
shown by arrows R. This causes the upper ends 24a to release engagement with
the
indexing sleeve. Upper ends 24a are pulled out of recess 321. When upper ends
24a are
pulled out of engagement with the indexing sleeve, spring 44 biases indexing
sleeve 26
down relative to the levers.
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When the levers pivot, ends 24b collapse radially out and actuator 11 can pass
through.
In so doing, ends 24b come to bear against the indexing sleeve and limit its
axial
movement. When actuator 11 has passed, the levers rotate back, arrows R2, such
that
upper ends 24a move back toward indexing sleeve 26 and ends 24a engage into
the next
recess 3211. Pivotal movement of lever back along arrows R2 can be driven by a
raised
area 33x striking the lower rear protrusion 24b' and urging it out as force is
applied
against ramped surface 24bn'.
When upper end protrusion 24a' is pivoted into the next recess 3211, the
protrusion 24a'
engages wall 32a and again stops the indexing sleeve from shifting down.
This motion is repeated by each passing actuator (similar to actuator 11 but
not shown)
until upper end protrusion 24a' is positioned in the upper most recess 32IV.
When upper end protrusion 24a' is positioned in the upper most recess 32IV,
the next
actuator that passes through the levers frees the upper end protrusion 24a'
from recesses
32 and allows sleeve 26 to be biased all the way down until support wall 34 is
positioned
behind levers 24. Sleeve 26 moves freely as biased by spring 44 since upper
protrusion
24a' is beyond recesses 32 and bottom rear protrusion 24b cannot stop the
movement of
sleeve 26, as it does not have a surface formed for engaging walls 32a.
In this entire process, sleeve 12 that carries levers 25 remains axially
stationary, while
levers 25 pivot and indexing sleeve 26 moves axially outside of sleeve 12.
When sleeve 26 is positioned with support wall 34 behind levers 25, the levers
cannot
rotate and ends 24b÷ protrude into inner bore 12a of sleeve. Indexing sleeve
26 may be
locked in this position relative to sleeve 12, if desired, to stop any further
movement of
the indexing sleeve. For this purpose, a lock can be employed to lock indexing
sleeve 26
to sleeve 12.
When a sleeve shifting device 14 is then launched from surface, it lands on
the levers.
Since levers 24 cannot collapse out of the way, device 14 is caught on the
constriction
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18
formed by the levers, which now form seat 16. Force that is generated by fluid
pressure
acting against device 14 and that force is transferred to shear pins 17.
Sufficient force
causes pins 17 to shear and sleeve 12 can shift down to open the ports 22.
Another lock,
such as c-ring 50 may lock the sleeve 12 in the open port position.
As will be appreciated, the downhole tool can include various components for
appropriate operations. For example, seals 60 may be positioned between sleeve
12 and
housing 20 to prevent fluid leakage and bypass. Torque resistors 62 may be
employed to
control against rotation of the sleeves 12, 26 about axis x.
Likewise, a mode of construction may be employed that best configures the
parts and/or
facilitates construction. For example, it is noted that many parts are formed
of
interconnected subcomponents.
The tool illustrated in Figures 1 to 4 may be employed in a method to index a
tool
through a plurality of inactive positions before arriving at an active
position. For
example, the indexing mechanism can be set to undergo any number of cycles up
to the
maximum number of recesses 32 before arriving at the active position. The
number of
cycles may be selected based on the number of actuators that are intended to
pass through
the tool prior to the tool being configured into its active position for its
main function.
In use, one or more of the tools with an indexing mechanism may be positioned
in a
tubing string. Because of their usefulness to increase the possible numbers of
sleeves in
any tubing string, the sliding sleeve tools may be installed above one or more
sleeves
having a set valve seat. For example, with reference to Figure 5, a wellbore
tubing string
apparatus may include a tubing string 614 having a long axis and an inner bore
618, a
first sleeve 632 in the tubing string inner bore, the first sleeve being
moveable along the
inner bore from a first position to a second position; a second sleeve 633 in
the tubing
string inner bore, the second sleeve offset from the first sleeve along the
long axis of the
tubing string, the second sleeve being moveable along the inner bore from a
third position
to a fourth position; and a third sleeve 634 offset from the second sleeve and
moveable
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along the tubular string from a fifth position to a sixth position. The first
sleeve may
have an indexing mechanism 638 such as according to one of the embodiments
described
above, including levers and the other components of the indexing mechanism,
which can
be actuated to form a non-collapsible valve seat (shown not yet formed). The
second and
third sleeves may be reconfigurable or, as shown, standard sleeves, with a set
valve seat
626a, 626b therein,
The sleeve furthest downhole, sleeve 634, includes valve seat 626b with a
diameter D1
and the sleeve thereabove has valve seat 626a with a diameter D2. Diameter D1
is
smaller than D2 and therefore sleeve 634 requires the smaller ball 623 to seal
thereagainst, which can easily pass through the seat of sleeve 633. Indexing
mechanism
638 of sleeve 632 includes a collapsible seat with an inner diameter D2.
This provides that the lowest sleeve 634 can be actuated to open first by
launching ball
623 which can pass without effect through all of the sleeves 633, 632
thereabove but will
land in and seal against seat 626b. Second sleeve 633 can likewise be actuated
to move
along tubing string 612 by ball 636, which is sized to pass through all of the
sleeves
thereabove to land and seal in seat 626a, so that pressure can be built up
thereabove.
However, in the illustrated embodiment, although ball 636 can pass through the
sleeves
thereabove, it may actuate those sleeves, for example sleeve 632, to generate
valve seats
thereon. For example, when ball 636 passes sleeve 632, the ball catches in
actuating
mechanism 638 and cycles the sleeve from one notch for an inactive position to
a next
notch for an active position and forms a non-collapsible seat. For example,
actuating
mechanism 638 on sleeve 632 includes the collapsible seat with a diameter D2
and is
formed to be axially moved by ball 636 passing thereby cycle the indexing
mechanism
and create the non-collapsible seat. However, ball 636 does pass through
sleeve 632 and
the ball can continue to seat 626a.
Of course, where the first sleeve, with the configurable valve seat, is
positioned above
other sleeves with valve seats formable or fixed thereon, the formation of the
valve seat
on the first seat should be timed or selected to avoid interference with
access to the valve
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seats therebelow. As such, for example, the inner diameter of any valve seat
formed on
the first sleeve should be sized to allow passage thereby of actuators (i.e.
plugging balls
or other plugs) for the valves therebelow. Alternately, and likely more
practical, the
timing of the actuation of the first sleeve to form a valve seat is delayed
until access to all
larger diameter valve seats therebelow is no longer necessary, for example all
such larger
diameter valve seats have been actuated or plugged.
In one embodiment as shown, the wellbore tubing string apparatus may be useful
for
wellbore fluid treatment and may include ports 617 over or past which sleeves
632, 633,
634 act.
In an embodiment where sleeves 632, 633, 634 are positioned to control the
condition of
ports 617, note that, as shown, in the closed port position, the sleeves can
be positioned
over their ports to close the ports against fluid flow therethrough. In
another
embodiment, the ports for one or both sleeves may have mounted thereon a cap
extending
into the tubing string inner bore and in the position permitting fluid flow,
their sleeve has
engaged against and opened the cap. The cap can be opened, for example, by
action of
the sleeve shearing the cap from its position over the port. Each sleeve may
control the
condition of one or more ports, grouped together or spaced axially apart along
a path of
travel for that sleeve along the tubing string. In yet another embodiment, the
ports may
have mounted thereover a sliding sleeve and in the position permitting fluid
flow, the first
sleeve has engaged and moved the sliding sleeve away from the first port.
The tubing string apparatus may also include outer annular packers 620 to
permit the
creation of isolated wellbore segments between adjacent packers. The packers
can be of
any desired type to seal between the wellbore and the tubing string. In one
embodiment,
at least one of the first, second and third packer is a solid body packer
including multiple
packing elements. In such a packer, it is desirable that the multiple packing
elements are
spaced apart.
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In use, a wellbore tubing string apparatus, such as that shown in Figure 5
including tools
with indexing mechanisms, for example according to one of the various
embodiments
described herein, may be run into a wellbore and installed as desired.
Thereafter the
sleeves may be shifted to allow fluid treatment or production through the
string.
Generally, the lower most sleeves are shifted first since access to them may
be
complicated by the process of shifting the sleeves thereabove. In one
embodiment, for
example, the actuator, such as a plugging ball may be conveyed to seal against
the seat of
a sleeve and fluid pressure may be increased to act against the plugging ball
and its seat
to move the sleeve. At some point, any indexable sleeves are actuated to form
their valve
seats. As will be appreciated from the foregoing description, an actuator for
such purpose
may take various forms. In one embodiment, as shown in Figure 5, the actuator
is a
device launched to also plug a lower sleeve or the actuator may act apart from
the
plugging ball for lower sleeves. In another embodiment, a plugging ball for a
lower
sleeve may actuate the formation of a valve seat on the first sleeve as it
passes thereby
and after which may land and seal against the valve seat of sleeve with a set
valve seat.
As another alternate method, a device from below a configurable sleeve can
actuate the
sleeve as it passes upwardly through the well. For example, in one embodiment,
a
plugging ball, when it is reversed by reverse flow of fluids, can move past
the first sleeve
and actuate the first sleeve to form a valve seat thereon.
The method can be useful for fluid treatment in a well, wherein the sleeves
operate to
open or close fluid ports through the tubular. The fluid treatment may be a
process for
borehole stimulation using stimulation fluids such as one or more of acid,
gelled acid,
gelled water, gelled oil, CO2, nitrogen and any of these fluids containing
proppants, such
as for example, sand or bauxite. The method can be conducted in an open hole
or in a
cased hole. In a cased hole, the casing may have to be perforated prior to
running the
tubing string into the wellbore, in order to provide access to the formation.
In an open
hole, the packers may be of the type known as solid body packers including a
solid,
extrudable packing element and, in some embodiments, solid body packers
include a
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22
plurality of extrudable packing elements. The methods may therefore, include
setting
packers about the tubular string and introducing fluids through the tubular
string,
Figures 6A to 6F show a method and system to allow several sliding sleeve
valves to be
run in a well, and to be selectively activated. The system and method employs
a tool as
described herein that will shift through several "inactive" shifting cycles
(Figures 1 to 3).
Once each valve passes through all its passive cycles, it can move to an
"active" state
(Figure 4). Once it shifts to the active state, the valve can be shifted from
closed to open
position, and thereby allow fluid placement through the open parts from the
tubing to the
annulus.
Figure 6A shows a tubing string 714 in a wellbore 712. A plurality of packers
720 a-f
can be expanded about the tubing string to segment the wellbore into a
plurality of zones
where the wellbore wall is the exposed formation along the length between
packers. The
string may be considered to have a plurality of intervals 1-5, each interval
identified as
between each adjacent pair of packers. Each interval includes at least one
port and a
sliding sleeve valve thereover (within the string), which together are
designated 716 a-c.
Sliding sleeve valve 716a includes a ball stop, herein called a seat, that
permits a ball-
actuated axial force to be applied to move the sleeve away from the ports it
covers.
Sliding sleeve valves 716b to 716e each include therein collapsible seats that
are
formable to non-collapsible seats when actuated to do so by use of an indexing
mechanism for movement of the seat between inactive positions where the seat
is
collapsible and an active position where the seats is activated and formed in
a non-
collapsible manner. For example, the seats of sleeves 716a to 716e may be
similar to seat
16 as shown in Figures 1 to 4, that is configurable to a ball retaining
diameter upon being
cycled into an active position.
Initially, as shown in Figure 6A, all ports are in the closed position,
wherein they are
closed by their respective sliding sleeve valves.
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As shown in Figure 6B, a ball 736 may be pumped onto a seat in the sleeve 716a
to open
its port in Interval 1. A wellbore fluid treatment may be effected through the
ports
opened by sleeve 716a. When the ball passes through the sleeves 716c-e in
Intervals 5, 4,
and 3, they make a passive shift from one inactive recess position to a next
inactive
recess position. When the ball passes through Interval 2, it moves the
indexing
mechanism to support the levers against pivoting at the support wall and a non-
collapsible ball stop is formed on sleeve 716b on that interval such that it
can be shifted
to the open position when desired.
Next, as shown in Figure 6C, a ball 736a is pumped onto the activated seat in
sleeve 716b
to open the port in Interval 2. When it passes through the sleeves in
Intervals 5, and 4,
they make a passive shift. When the ball passes through Interval 3, it moves
sleeve 716c
from an inactive position to an active position so that it can be shifted to
the open
position when desired. When ball 736a lands in sleeve 716b in Interval 2, it
opens that
sleeve by landing on the ball stop formed in Figure 613 and a wellbore fluid
treatment
may be effected through the ports opened by sleeve 716b.
Thereafter, as shown in Figure 6D, a ball 736b is pumped onto the activated
seat in sleeve
716c to open the port in Interval 3. When ball 736b lands in sleeve 716c, it
opens that
sleeve by landing on the ball stop formed in Figure 6C and a wellbore fluid
treatment
may be effected through the ports opened by sleeve 716c. When ball 736b passes
through the sleeve 716e in Interval 5, that sleeve makes a passive shift
moving from one
inactive recess position to a next inactive recess position. When the ball
passes through
Interval 4, it moves sleeve 716d from inactive to active, for example, with
support wall
positioned behind the levers, so that sleeve 716d can be shifted to the open
position when
desired.
Thereafter, as shown in Figure 6E, a ball 736c is pumped onto the activated
seat of sleeve
716d to open the port in Interval 4 and a fluid treatment may be effected
therethrough.
When ball 736c passes through Interval 5, it moves sleeve 716e from inactive
to active so
that it can be shifted to the open position when desired.
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24
Thereafter, as shown in Figure 6F, a ball 736d is pumped onto the activated
seat of sleeve
716e to open the port in Interval 5 completing the opening of all ports.
With reference to the tool of Figures 1 to 4, it is noted that sleeve 716b of
Interval 2
would be installed with the lever in the upper most recess 32VI, such that
after one
actuation thereof (i.e. after one ball passes therethrough), the indexing
sleeve would
move to position with support wall 34 behind levers 24 to form seat 16 in a
non-
collapsible configuration. Likewise, the sleeve 716c of Interval 3 would be
installed with
its lever upper ends 24a in the recess next to recess 32VI, such that after
two actuations
thereof (i.e. after two balls pass therethrough), the indexing sleeve would
move to support
the levers and the seat would be activated in a non-collapsible form. The
other sleeves
716d and 716e would be installed with their levers engaging the third and
fourth recesses,
respectively.
When the ports are each opened, the formation accessed therethrough can be
stimulated
as by fracturing. It is noted, therefore, that the formation can be treated in
a focused,
staged manner. It is also noted that balls 736 - 736d may all be the same
size, but still
this portion of the formation can be treated in a focused, staged manner,
through one port
at a time. Note that while only five ports are shown in this segment of the
string, more
than five ports can be run in a string. The intervals need not be directly
adjacent, as
shown, but can be spaced and there can be more than one port/sleeve per
interval (i.e. at
least two ports in one interval that open after the same number of actuations
or which
open in sequence). Further similar series of ports could be employed above
and/or below
this series, which use other sized balls. Of course, any sleeves below that
use a different
sized ball will use a smaller ball that can pass through the illustrated
sleeves without
actuating them.
This system and tool of Figures 6A to 6F allows a single sized ball or other
plug to
function numerous valves. The sleeves may sense the passing of a ball by the
indexing
mechanism. As shown by sleeve 716a, the system can use combinations of solid
ball
seats and sleeves with indexing mechanisms. The system allows for
installations of fluid
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placement liners of very long length forming large numbers of separately
accessible
wellbore zones.
The previous description of the disclosed embodiments is provided to enable
any person
skilled in the art to make or use the present invention. Various modifications
to those
embodiments will be readily apparent to those skilled in the art, and the
generic
principles defined herein may be applied to other embodiments without
departing from
the spirit or scope of the invention. Thus, the present invention is not
intended to be
limited to the embodiments shown herein, but is to be accorded the full scope
consistent
with the claims, wherein reference to an element in the singular, such as by
use of the
article "a" or "an" is not intended to mean "one and only one" unless
specifically so
stated, but rather "one or more". All structural and functional equivalents to
the elements
of the various embodiments described throughout the disclosure that are known
or later
come to be known to those of ordinary skill in the art are intended to be
encompassed by
the elements of the claims. Moreover, nothing disclosed herein is intended to
be
dedicated to the public regardless of whether such disclosure is explicitly
recited in the
claims. No claim element is to be construed under the provisions of 35 USC
112, sixth
paragraph, unless the element is expressly recited using the phrase "means
for" or "step
for".
