U.S. patent application number 14/428293 was filed with the patent office on 2015-09-24 for wellbore tool with indexing mechanism and method.
The applicant listed for this patent is PACKERS PLUS ENERGY SERVICES INC.. Invention is credited to Brandon Layne Avery.
Application Number | 20150267506 14/428293 |
Document ID | / |
Family ID | 50340492 |
Filed Date | 2015-09-24 |
United States Patent
Application |
20150267506 |
Kind Code |
A1 |
Avery; Brandon Layne |
September 24, 2015 |
WELLBORE TOOL WITH INDEXING MECHANISM AND METHOD
Abstract
A wellbore tool, a wellbore fluid treatment string and a method
with an indexing mechanism. The indexing mechanism can be shifted
through one or more inactive positions before finally shifting into
an active condition. The indexing mechanism is particularly useful
with a plug that lands in a seat to impart an axially directed
force on the mechanism before passing through the seat.
Inventors: |
Avery; Brandon Layne;
(Edmonton, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PACKERS PLUS ENERGY SERVICES INC. |
Calgary |
|
CA |
|
|
Family ID: |
50340492 |
Appl. No.: |
14/428293 |
Filed: |
September 18, 2013 |
PCT Filed: |
September 18, 2013 |
PCT NO: |
PCT/CA2013/050713 |
371 Date: |
March 13, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61703131 |
Sep 19, 2012 |
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|
Current U.S.
Class: |
166/373 ;
166/185; 166/318 |
Current CPC
Class: |
E21B 2200/06 20200501;
E21B 33/124 20130101; E21B 34/14 20130101; E21B 34/12 20130101 |
International
Class: |
E21B 34/12 20060101
E21B034/12; E21B 33/124 20060101 E21B033/124 |
Claims
1. A wellbore tool that is actuable through a plurality of
positions comprising: a tubular housing including an upper end, a
lower end, an axis extending between the ends 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 ring in the
tubular housing, the indexing ring including an inner bore and
being rotatably movable about the axis, and an inner sleeve
positioned within the tubular housing and extending through the
inner bore, the inner sleeve having an axial bore extending
therethrough and a wall thickness, and a plurality of pawls forming
a seat on the inner sleeve, each of the plurality of pawls being
pivotally connected to the inner sleeve and having an inner facing
surface open to and biased into the axial bore and a back side
surface positioned for engagement with the indexing ring; and an
actuator for passing through the axial bore and contacting the
inner facing surfaces to drive the plurality of pawls radially out
into full meshing engagement with the indexing ring to thereby
drive the indexing ring to rotate and to move the tool mechanism
from the first inactive position toward the active position.
2. The wellbore tool of claim 1 wherein the indexing ring is
rotatably moveable in one rotational direction only about the
axis.
3. The wellbore tool of claim 1 wherein the indexing ring is a gear
ring with an internally toothed profile and the plurality of pawls
include at least one protrusion on the back side surface to mesh
with the internally toothed profile.
4. The wellbore tool of claim 1 wherein the plurality of pawls are
each pivotally connected to rotate about a fulcrum axis
substantially parallel to the axis.
5. The wellbore tool of claim 1 wherein the sleeve is retained
against rotating about the axis.
6. The wellbore tool of claim 1 wherein in the active position, the
indexing ring is stopped from rotating.
7. The wellbore tool of claim 1 wherein in the active position, the
plurality of pawls are stopped from rotation into full meshing
engagement such that a sleeve shifting device cannot pass through
the plurality of pawls.
8. The wellbore tool of claim 1 wherein the tool mechanism is the
seat and in the active position, the seat forms a non-expandable
ball seat.
9. The wellbore tool of claim 6 wherein the seat in the inactive
position is expandable.
10. A wellbore sliding sleeve sub comprising: a tubular housing
including an upper end, a lower end, an axis extending through the
upper end and the lower end and a wall defined between an inner
surface and an outer surface; a port through the wall of the
tubular housing; a sleeve in the tubular housing, the sleeve having
an inner bore and being moveable from a closed position overlying
the port to an open position exposing the port; a ball seat on the
sleeve configurable between an expandable form and non-expandable
form, the ball seat including a plurality of pawls, each pawl
having a front side surface exposed in the inner bore and a
backside surface opposite the front side surface and each pawl
being pivotally connected to the sleeve through a fulcrum having an
axis of rotation substantially parallel to the axis such that the
pawls are rotationally moveable between a constricted position
protruding into the inner bore and an expanded position having an
inner diameter greater than the constricted position; an indexing
mechanism for reconfiguring the ball seat from the inactive
position to the active position, the indexing mechanism including a
pawl protrusion on the back side surface of at least one pawl and
an indexing ring with a plurality of teeth on its inner facing
surface, the plurality of teeth forming at least one valley capable
of meshing with the pawl protrusion, the indexing ring being
rotatable relative to the sleeve and encircling the sleeve about
the plurality of pawls, expansion of the plurality of pawls from
the constricted position to the expanded position driving meshing
of the pawl protrusion with the at least one valley and rotation of
the indexing ring to accommodate the meshing; and an actuator for
passing through the inner bore and contacting the front side
surfaces of the plurality of pawls to drive the pawls to the
expanded position to force the pawl protrusion to mesh with the
valley of the indexing ring and thereby to rotate the indexing ring
relative to the sleeve to reconfigure the ball seat from the
expandable form toward the non-expandable form.
11. The wellbore sliding sleeve sub of claim 10 wherein
misalignment between the pawl protrusion and the valley drives
rotation of the indexing ring when the pawl protrusion meshes with
the valley.
12. The wellbore sliding sleeve sub of claim 10 wherein the
indexing ring includes a number of valleys and the number of
valleys defines a number of actuators that are passable through the
plurality of pawls before the ball seat is moved to the
non-expandable form.
13. The wellbore sliding sleeve sub of claim 10 wherein in the
non-expandable form the indexing ring is stopped from rotation and
the pawl protrusion is stopped from meshing.
14. A wellbore fluid treatment string comprising a string and
sliding sleeve sub according to claim 11, a first annular packer on
the string uphole of the sliding sleeve sub and a second annular
packer on the string downhole of the sliding sleeve sub, the first
annular packer and the second annular packer being expandable to
form an isolated wellbore segment therebetween.
15. The wellbore fluid treatment string of claim 14 further
comprising a sleeve-shifting device to land on the ball seat after
the ball seat is configured into the non-expandable form.
16. A method for actuating a downhole tool to an active position,
the method comprising: passing an actuator through a expandable
ball seat in the downhole tool to permit incremental movement of an
indexing ring about the ball seat until the indexing ring moves to
a final position wherein the ball seat is held by the indexing ring
against expanding and is capable of catching a sleeve shifting
device.
17. The method of claim 16 wherein during passing the ball seat
remains axially stationary in the downhole tool.
18. The method of claim 16 wherein passing includes driving a
plurality of pawls that form the ball seat from a constricting
position out into full meshing engagement with the indexing ring as
the actuator passes over the plurality of pawls and biasing the
plurality of pawls back into the constricting position when the
actuator clears the plurality of pawls.
Description
PRIORITY APPLICATION
[0001] This application claims priority to U.S. provisional
application Ser. No. 61/703,131, filed Sep. 19, 2012.
FIELD OF THE INVENTION
[0002] The invention relates to a wellbore tool with an indexing
mechanism and methods for using the tool.
BACKGROUND OF THE INVENTION
[0003] 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.
[0004] 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 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.
[0005] 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 33/4'' ball, then the well treatment string will
generally be limited to approximately eleven sleeves and,
therefore, can treat in only eleven stages.
[0006] 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
[0007] In accordance with an aspect of the present invention, there
is provided wellbore tool that is actuable through a plurality of
positions comprising: a tubular housing including an upper end, a
lower end, an axis extending between the ends 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 ring in the
tubular housing, the indexing ring including an inner bore and
being rotatably movable about the axis, and an inner sleeve
positioned within the tubular housing and extending through the
inner bore, the inner sleeve having an axial bore extending
therethrough and a wall thickness, and a plurality of pawls forming
a seat on the inner sleeve, each of the plurality of pawls being
pivotally connected to the inner sleeve and having an inner facing
surface open to and biased into the axial bore and a back side
surface positioned for engagement with the indexing ring; and an
actuator for passing through the axial bore and contacting the
inner facing surfaces to drive the plurality of pawls radially out
into full meshing engagement with the indexing ring to thereby
drive the indexing ring to rotate and to move the tool mechanism
from the first inactive position toward the active position.
[0008] 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, an axis
extending through the upper end and the lower end and a wall
defined between an inner surface and an outer surface; a port
through the wall of the tubular housing; a sleeve in the tubular
housing, the sleeve having an inner bore and being moveable from a
closed position overlying the port to an open position exposing the
port; a ball seat on the sleeve configurable between an expandable
form and non-expandable form, the ball seat including a plurality
of pawls, each pawl having a front side surface exposed in the
inner bore and a backside surface opposite the front side surface
and each pawl being pivotally connected to the sleeve through a
fulcrum having an axis of rotation substantially parallel to the
axis such that the pawls are rotationally moveable between a
constricted position protruding into the inner bore and an expanded
position having an inner diameter greater than the constricted
position; an indexing mechanism for reconfiguring the ball seat
from the inactive position to the active position, the indexing
mechanism including a pawl protrusion on the back side surface of
at least one pawl and an indexing ring with a plurality of teeth on
its inner facing surface, the plurality of teeth forming at least
one valley capable of meshing with the pawl protrusion, the
indexing ring being rotatable relative to the sleeve and encircling
the sleeve about the plurality of pawls, expansion of the plurality
of pawls from the constricted position to the expanded position
driving meshing of the pawl protrusion with the at least one valley
and rotation of the indexing ring to accommodate the meshing; and
an actuator for passing through the inner bore and contacting the
front side surfaces of the plurality of pawls to drive the pawls to
the expanded position to force the pawl protrusion to mesh with the
valley of the indexing ring and thereby to rotate the indexing ring
relative to the sleeve to reconfigure the ball seat from the
expandable form toward the non-expandable form.
[0009] In accordance with another aspect of the present invention,
there is provided a method for actuating a downhole tool to an
active position, the method comprising: passing an actuator through
a expandable ball seat in the downhole tool to permit incremental
movement of an indexing ring about the ball seat until the indexing
ring moves to a final position wherein the ball seat is held by the
indexing ring against expanding and is capable of catching a sleeve
shifting device.
[0010] 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
[0011] 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:
[0012] FIGS. 1 to 4 are views of a wellbore tool with an indexing
mechanism, wherein:
[0013] FIG. 1 is a sectional view through a wellbore tool in a
position ready to be moved through an indexing cycle;
[0014] FIG. 2 is an enlarged view of area A in FIG. 1;
[0015] FIG. 3A is an isometric view of a portion of an inner sleeve
of the wellbore tool of FIG. 1. The portion of the sleeve is that
portion below line I-I of FIG. 1;
[0016] FIG. 3B is another isometric view of a portion of an inner
sleeve of the wellbore tool of FIG. 1; and
[0017] FIGS. 4A and 4B, sometimes referred to collectively as FIG.
4, are enlarged end views of the portion of the sleeve of FIG. 3
showing sequential stages in the indexing cycle;
[0018] FIG. 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
[0019] FIGS. 6A to 6F, sometimes referred to collectively as FIG.
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
[0020] 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.
[0021] A wellbore tool that is actuable through a plurality of
positions may include a tubular housing including an upper end, a
lower end, an axis extending between the ends 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 ring in the
tubular housing, the indexing ring including an inner bore and
being rotatably movable about the axis, and an inner sleeve
positioned within the tubular housing and extending through the
inner bore, the inner sleeve having an axial bore extending
therethrough and a wall thickness, and a plurality of pawls forming
a seat on the inner sleeve, each of the plurality of pawls being
pivotally connected at one end to the inner sleeve and having an
inner facing surface open to and biased into the axial bore and a
back side surface positioned for engagement with the indexing ring;
and an actuator for passing through the axial bore and contacting
the inner facing surfaces to drive the plurality of pawls radially
out into engagement with the indexing ring to drive the indexing
ring to rotate and move the tool mechanism from the first inactive
position toward the active position.
[0022] 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 may be via an actuator passing
through the tool while it is installed downhole. The actuator may
be launched from surface. The actuator may be free to move through
the wellbore toward and through the tool without connection to
surface. Passing the actuator through the indexing mechanism
permits incremental movement of the indexing ring to take the
indexing mechanism through an indexing cycle. After one or more
actuators are passed through the tool, thereby moving the tool
through one or more indexing cycles, the indexing ring moves to a
final position wherein the tool is brought into an active position.
The indexing mechanism includes the plurality of pawls protruding
into the inner bore of the tool such that it can receive the
applied force of the actuator passing therethrough. The plurality
of pawls protrude into the inner bore of the tool, and define a
constriction in the bore of the sleeve, the constriction having an
inner diameter less than the outer diameter of the actuator used to
operate the indexing mechanism. However, the pawls can be pushed
radially outwardly (called opening or expanding herein) if
sufficient force is applied, such expanding enlarges the inner
diameter to be greater than the inner diameter in the constricted
position and allows the actuator to pass. The indexing mechanism in
one embodiment, also includes an indexing ring that senses when the
pawls have expanded and can be set to allow a selected number of
actuators to pass before moving into a final position, wherein the
pawls are no longer capable of expanding. In one embodiment, the
plurality of pawls together form a ball seat that in the final
position is held against expanding radially outwardly. In this
position, the ball seat is active to catch a sleeve-shifting device
to drive movement of the inner sleeve.
[0023] 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.
[0024] 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
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 expandable such that the ball may
pass through the seat.
[0025] 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.
[0026] 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.
[0027] With reference to FIGS. 1 to 4B, an example of a wellbore
sliding sleeve tool 10 is shown that is modified by the passage
therethrough of one or more actuators 11. The passage of the
actuators eventually configures 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
shiftable, it can be modified by the passage of one or more
actuators to be shiftable. 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-expandable
form (FIG. 4B) 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 where the seat is
expandable, prior to placement into a position wherein the seat is
actually configured in a non-expandable 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) positions, before finally moving
into an active position to form the final, non-expandable valve
seat 16.
[0028] In the drawings, FIG. 1 shows tool 10 in a run in position
just about to be cycled by actuator 11, which in this embodiment is
in the form of a ball; FIG. 4A shows the tool in an inactive
position, with the actuator passing through the tool and wherein
the ball seat is fully expanded; and FIG. 4B shows tool 10 in an
active position, with seat 16 formed in a non-expandable way to
stop a sleeve shifting device 14. The sleeve-shifting device 14 has
not yet landed on the seat, but its outer diameter can be seen.
When the ball lands, the seat will expand radially out to some
further degree to an unexpanded diameter IDu, but not enough to
allow the device to pass.
[0029] 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 axial 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
concentrically relative to inner surface 20c through ends 20a,
20b.
[0030] 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 axial 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 (FIG. 1) and a
position at least partially retracted from, and therefore opening,
port 22. In the open position in the embodiment, sleeve 12 would be
moved to butt at its end 12c against shoulder 20e.
[0031] Sleeve 12 includes an inner bore 12a and an outer facing
surface 12b. The sleeve includes seat 16 in bore 12a. Seat 16 is
the tool mechanism capable of being configured through a plurality
of positions including one or more inactive positions and an active
position. In the inactive positions (FIGS. 1 and 4A) seat 16 is
expandable and allows any actuator, such as actuator 11, that lands
therein to pass. In the active position (FIG. 4B), seat 16 is
configured in a non-expandable way and is capable of catching and
retaining sleeve-shifting device 14. In particular, seat 16 in the
active position cannot expand and sleeve-shifting device 14 that is
sized to be larger than the unexpanded IDu 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 the 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.
[0032] 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 uphole of the tool, such as from surface, and sized to
have an outer diameter greater than the unexpanded IDu of seat 16.
The actuator 11 may actually be identical to sleeve shifting device
14, but the seat expands 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.
[0033] The indexing mechanism includes a plurality of pawls 24 and
an indexing ring 26. The pawls 24 protrude into the inner bore of
sleeve 12 to sense the passage of an actuator. Herein, pawls 24
also form seat 16. Thus, seat 16 is the tool mechanism and also
part of the indexing mechanism.
[0034] Pawls 24 each include a base end 24a, front side surface 24b
and a backside surface 24c.
[0035] Pawls 24 are each connected at base end 24a to sleeve 12 by
a fulcrum pin 28, here in the form of shoulder bolts. Each fulcrum
pin 28 connects its pawl 24 such that the pawl pivots about an axis
y, which follows the length of the pin and is substantially
parallel to axis x. Each pawl 24 is connected by pin 28 in a slot
30 formed through the wall of sleeve 12 such that, when pivoting,
the front side surface 24b is exposed and can protrude into inner
bore 12a and back side surface 24c is exposed on outer surface 12b.
Pawls 24, being exposed in the sleeve's bore 12a, can be acted upon
by structures passing through the sleeve's bore.
[0036] Pawls 24 are normally biased to protrude into the inner bore
12a by a spring 31 such as in the form of a garter spring. The bias
in spring 31 can be overcome to cause the springs to expand.
[0037] The pawls are spaced apart about a circumference of sleeve
12 and effectively create a ring coaxial with axis x. Pawls 24 are
each a segment of a ring and, therefore, may each be arcuate along
their length from their base ends 24a to their outboard ends 24d.
As such, the pawls can have a concave curvature along their front
side surfaces and a convex curvature along their back side
surfaces.
[0038] Each pawl has on its back side surface 24c one or more pawl
protrusions 32, for example, a plurality of which may be formed as
ratchet teeth.
[0039] Indexing ring 26 is positioned concentrically about the
sleeve, aligned behind pawls 24. Pawls 24, when expanding (i.e.
moving radially outwardly), can contact indexing ring 26. Ring 26
extends substantially concentrically about slot 30.
[0040] Indexing ring 26 includes an inner bore with an inner facing
surface that includes a plurality of teeth 34. Thus, indexing ring
26 has the form of an internally toothed gear ring. The plurality
of teeth form at least one valley 34a between two adjacent teeth.
Because there are many teeth in the illustrated embodiment, there
are many valleys 34a. Teeth 34 and the pawl protrusions are shaped
so that pawl protrusions 32 on pawls 24 are capable of meshing into
the valleys between adjacent teeth. Meshing of protrusions 32 into
the valleys, as when pawls 24 expand, causes rotation of ring
26.
[0041] While indexing ring 26 is rotatable about sleeve 12,
rotation of ring 26 is limited to being in one direction only. In
this illustrated embodiment, for example, ring 26 includes a second
internal tooth profile 36 that interacts with a external toothed
profile 38 on sleeve's outer facing surface 12b. Alternately or in
addition, teeth 34 may be asymmetrical, with each tooth flank
having a moderate slope on one side and a much steeper sloped flank
on the other side so that rotation is urged in one direction over
the other.
[0042] Teeth 36, 38 have a different profile than protrusions 32
and teeth 34, such that when teeth 36, 38 fully mesh, protrusions
32 are out of alignment with the valleys between teeth 34 and vice
versa. In the illustrated embodiment, teeth 36, 38 have a finer
pitch than teeth 34.
[0043] Indexing ring 26 also includes a tab 42 extending from its
edge. While indexing ring 26 can rotate about sleeve 12, rotation
is stopped when tab 42 butts against a stop tab 44 on sleeve 12.
While tab 42 can be positioned to move along a gap 46 between ring
26 and sleeve 12, tab 42 eventually is stopped against the stop tab
44 protruding from sleeve 12 into gap 46.
[0044] In this embodiment, indexing ring 26 and sleeve 12 each have
multi-part constructions to facilitate assembly. Sleeve 12 includes
a main sleeve having an upper part 48a and a lower part 48b, with
internal housings 49, 50 secured therewithin on either side of
pawls 24. Indexing ring 26 includes an internally toothed ring 52
with teeth 34 and two rings 54, 55 on either side of ring 52. One
or both rings 54, 55 carry the internal tooth profiles 36. Rings
54, 55 overlie the sleeve beyond ends of slot 30. Rings 52, 54, 55
are secured together to act as one ring as by use of interlocking
keys 56. In addition, all parts of sleeve 12 and ring 26 are
connected to move together axially.
[0045] While the illustrated tool includes four pawls 24, more or
fewer pawls can be employed. However, there is some benefit in
providing a plurality of pawls substantially equally spaced apart
about the sleeve's circumference so that any forces on the pawls
may be balanced about the circumference and there may be a back up
of pawls to overcome a failure of one pawl, since each pawl may
operate independently.
[0046] Indexing ring 26 works with pawls 24 to index the tool
through a number of cycles of inactive positions before reaching
the active position. Pawls 24 normally are biased inwardly to
protrude into the sleeve's inner bore 12a. In particular, pawls 24
normally extend inwardly through slot 30 and define a constriction
having an inner diameter IDu in the sleeve's inner bore. However,
when pawls 24 are expanded (i.e. driven radially outwardly) as by
an actuator 11 passing therethrough, backside 24c of each pawl
bears against indexing ring 26. The protrusions 32 on pawls 24
drive against teeth 34 on ring 26 and seek to mesh with them. For
the pawls to expand sufficiently for an actuator to pass,
protrusions/teeth 32, 34 must fully mesh. When protrusions/teeth
32, 34 fully mesh, the one or more pawl protrusions 32 drive into
valleys 34a and any misalignment causes ring 26 to rotate a small
amount as each pawl protrusion 32 slides down along the flank of a
tooth into the base of the valley. Ring 26 can only rotate in one
direction. As soon as the actuator passes, however, pawls 24 are
biased inwardly by spring 31. In addition, because teeth 36, 38
have a different profile than teeth 34, the full meshing of
protrusions/teeth 32, 34 causes misalignment of teeth 36, 38 and
once protrusions 32 come out of engagement with teeth 34 and ring
26 then rotates to bring teeth 36, 38 into proper alignment. This
advances ring again a small amount, and causes misalignment of
protrusions 32 and teeth 34 such that when the pawls are expanded
out again, ring 26 must be rotated again to permit alignment and
full meshing of protrusions 32 and teeth 34.
[0047] Eventually, ring 26 reaches a position where it can no
longer rotate to allow full meshing of protrusions 32 with teeth
34. When protrusions/teeth 32, 34 are unable to fully mesh, the
indexing mechanism places pawls in a final position, where they can
no longer expand. In this position, a sleeve shifting device 14 is
caught in the constriction of the inner diameter IDu. Even though
sleeve shifting device 14 may have the same structure and the same
diameter as the one or more actuators that have already passed
through pawls 24, device 14 cannot pass because pawls cannot mesh
with teeth 34 and therefore cannot fully expand out of axial bore
12a.
[0048] The indexing mechanism operation depends on the interaction
of pawls 24 against ring 26 and the exposure of the pawls in the
sleeve's inner bore, where they can be acted upon by the
actuators.
[0049] During indexing, the pawls are moved by passing actuators
and the indexing ring, moves incrementally rotationally about axis
x as driven by the pawls. Rotation of indexing ring 26 counts the
number of actuators that pass. While each pawl requires only one
protrusion that moves from one valley to a following valley between
teeth on indexing ring, providing a plurality of protrusions 32 on
each pawl increases the durability of the mechanism.
[0050] Knowing the degree of rotation that the ring moves through
when each actuator passes, allows the ring to be set to the desired
number of actuators to be passed before the pawls are locked into
the active position. The pawls will lock when their protrusions are
no longer able to fully mesh with the valleys on the indexing ring
and that is when the indexing ring tab 42 stops against the sleeve
stop tab 44. Thus, the ring can be rotated to move the tab 42 away
from the stop tab a number of incremental rotations equal to the
number of actuators that are to pass before the active position of
the seat is reached. Effectively, this can be determined by the
number of valleys on the ring through which the protrusions on the
pawls can move before the tab is stopped against further rotation.
The ring is set during assembly of the tool, as by rotating the
ring to the predetermined number of actuators that are to pass
before the tool assumes the final position. The indexing ring can
have indicator numbers printed on its external surface 26a and
these numbers can be lined up with a reference point, such as the
stop tab, on the sleeve.
[0051] The indexing mechanism is activated to move through an
indexing cycle when an actuator 11 moving downhole, arrow A, lands
on the pawls, which are biased into an internally constricted
position by biasing spring 31 to have an inner diameter between
them less that the outer diameter of the actuator. As the actuator
pushes on the pawls, the pawls rotate, arrow O, about their
fulcrums 28 to open up and push on the indexing ring. The indexing
ring rotates when the pawls come to bear against it, due to the
meshing action of the protrusions/teeth 32, 34 and the rotational
restriction imparted by internal toothed surface 36. When the
protrusions seek to mesh entirely, the protrusions on pawls 24
cause ring 26 to rotate slightly. When the pawls have opened
entirely, the indexing ring is advanced by one incremental rotation
and the inner diameter ID across the pawls is equal to or greater
than the outer diameter of the actuator. The actuator 11 passes
through the pawls and the spring forces, arrow I, the pawls back
into a constricted position in bore 12a.
[0052] After the last stage is reached, tab 42 on ring 26 stops on
the corresponding stop tap on the sleeve 12. This stops all
rotation of the ring 26 and locks pawls 24 in the final position,
wherein they are constricted, protruding into inner bore 12a of the
sleeve and have an unexpanded inner diameter IDu thereacross. Pawls
24 form seat 16 that cannot expand and the sleeve is ready to be
shifted open (FIGS. 3 and 4B). Any sleeve shifting device 14 that
passes into sleeve 12 cannot pass through pawls 24. This occurs
even though sleeve shifting device 14 may be identical to actuators
11. Since the pawls are locked against expanding, the force that
would previously open the pawls is transmitted to shear pins 17
connecting the sleeve to the tubular housing 20. The pressure
applied to the ball causes the shear pins 17 to shear and sleeve 12
shifts down to the open position and can be locked into the open
position by a c-ring acting between the sleeve and the tubular
housing.
[0053] In the starting position, as the tool is run into the well,
ring 26 is at the set starting position. As actuators are passed
through, the ring is rotated one rotation at a time towards a
position with tab 42 stopped against the stop tab.
[0054] The number of times that a pawl is capable of expanding to
allow an actuator to pass before arriving at the active position,
where it can no longer expand, depends on the position of the ring
tab 42 relative to the stop tab on the sleeve and, in particular,
the number of times that indexing ring can be incrementally rotated
by pawls.
[0055] 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.
[0056] In this entire process, sleeve 12 that carries pawls 24
remains axially and rotationally stationary, while pawls 24 pivot
and indexing ring 26 moves rotationally outside of sleeve 12.
[0057] 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, such as pins 61 in
slots 62, may be employed to control against rotation of the sleeve
12 about axis x.
[0058] Likewise, a mode of construction may be employed that best
configures the parts and/or facilitates construction. For example,
as noted, various parts may be formed of interconnected
subcomponents.
[0059] The tool illustrated in FIGS. 1 to 4B 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 incremental rotations depending on the size of
protrusions/teeth 32, 34, number of pawls, etc. 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.
[0060] 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 FIG. 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 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 pawls and the other
components of the indexing mechanism, which can be actuated to form
a non-expandable 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.
[0061] 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 expandable seat
with an inner diameter D2.
[0062] 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 that 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-expandable seat.
For example, actuating mechanism 638 on sleeve 632 includes the
expandable 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-expandable seat. However, ball 636 does pass through
sleeve 632 and the ball can continue to seat 626a.
[0063] 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 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.
[0064] 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.
[0065] 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.
[0066] 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.
[0067] In use, a wellbore tubing string apparatus, such as that
shown in FIG. 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 FIG. 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.
[0068] 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, CO.sub.2, 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 plurality of extrudable packing elements. The methods may
therefore, include setting packers about the tubular string and
introducing fluids through the tubular string.
[0069] FIGS. 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 (FIGS. 1
to 3). Once each valve passes through all its passive cycles, it
can move to an "active" state (FIG. 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.
[0070] FIG. 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-e. 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
expandable seats, which are formable to non-expandable seats when
actuated to do so by use of an indexing mechanism for movement of
the seat between inactive positions where the seat is expandable
and an active position where the seats is activated and formed in a
non-expandable manner. For example, the seats of sleeves 716a to
716e may be similar to seat 16 as shown in FIGS. 1 to 4, that is
configurable to a ball retaining diameter upon being cycled into an
active position.
[0071] Initially, as shown in FIG. 6A, all ports are in the closed
position, wherein they are closed by their respective sliding
sleeve valves.
[0072] As shown in FIG. 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, pawls make a passive shift to move their indexing rings one
position closer to tab 42 set against the stop tab of the sleeve.
When the ball passes through Interval 2, it moves the indexing
mechanism to support the pawls against pivoting and a
non-expandable ball stop is formed on sleeve 716b on that interval
such that it can be shifted to the open position when desired.
[0073] Next, as shown in FIG. 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 FIG. 6B and a wellbore fluid treatment
may be effected through the ports opened by sleeve 716b.
[0074] Thereafter, as shown in FIG. 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 FIG. 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 where pawls drive the indexing ring to
advance one incremental rotation closer to a position where the
ring's tab 42 is stopped from further rotation. When the ball
passes through Interval 4, it moves sleeve 716d from inactive to
active, for example with tab 42 set against a stop tab on the
sleeve so the indexing ring can no longer be rotated, so that
sleeve 716d can be shifted to the open position when desired.
[0075] Thereafter, as shown in FIG. 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 effect 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.
[0076] Thereafter, as shown in FIG. 6F, a ball 736d is pumped onto
the activated seat of sleeve 716e to open the port in Interval 5
completing opening of all ports.
[0077] With reference to the tool of FIGS. 1 to 4B, it is noted
that sleeve 716b of Interval 2 would be installed with the indexing
ring only one rotational position away from being stopped, such
that after only one actuation thereof (i.e. after one ball passes
therethrough), the indexing ring would be moved to stopped position
and pawls 24 are in a position forming seat 16 in a non-expandable
configuration. Likewise, the sleeve 716c of Interval 3 would be
installed with its indexing ring just two rotations from a stopped
position, such that after two actuations thereof (i.e. after two
balls pass therethrough), the indexing ring would be stopped from
further movement and the pawls would be locked from expanding.
Thus, the seat would be activated in a non-expandable form. The
other sleeves 716d and 716e would be installed with their rings
rotated to provide for three and four rotations, respectively.
[0078] 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.
[0079] This system and tool of FIGS. 6A to 6F provides a
substantially unrestricted internal diameter along the string and
allows a single sized ball to function numerous valves. The sleeves
may sense the passing of a ball. 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
placement liners of very long length forming large numbers of
separately accessible wellbore zones.
[0080] 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".
* * * * *