US20150267506A1

US20150267506A1 - Wellbore tool with indexing mechanism and method

Info

Publication number: US20150267506A1
Application number: US14/428,293
Authority: US
Inventors: Brandon Layne Avery
Original assignee: Packers Plus Energy Services Inc
Current assignee: Packers Plus Energy Services Inc
Priority date: 2012-09-19
Filing date: 2013-09-18
Publication date: 2015-09-24
Also published as: CA2889268A1; WO2014043807A1

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.

Description

PRIORITY APPLICATION

This application claims priority to U.S. provisional application Ser. No. 61/703,131, filed Sep. 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 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 3¾″ 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 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.
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.
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.
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:

FIGS. 1 to 4 are views of a wellbore tool with an indexing mechanism, wherein:

FIG. 1 is a sectional view through a wellbore tool in a position ready to be moved through an indexing cycle;

FIG. 2 is an enlarged view of area A in FIG. 1;

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;

FIG. 3B is another isometric view of a portion of an inner sleeve of the wellbore tool of FIG. 1; and

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;

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

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

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, 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.
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.
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 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.
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 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.
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.
The illustrated sliding sleeve tool includes a tubular housing 20 including an upper end 20 a, a lower end 20 b, an inner surface 20 c defining an inner axial bore and an outer surface 20 d. Although not shown, the sliding sleeve tool, may be formed as a sub with its tubular housing 20 having ends 20 a, 20 b 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 20 c through ends 20 a, 20 b.
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 20 d. 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 12 c against shoulder 20 e.
Sleeve 12 includes an inner bore 12 a and an outer facing surface 12 b. The sleeve includes seat 16 in bore 12 a. 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.
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.
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.
Pawls 24 each include a base end 24 a, front side surface 24 b and a backside surface 24 c.
Pawls 24 are each connected at base end 24 a 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 24 b is exposed and can protrude into inner bore 12 a and back side surface 24 c is exposed on outer surface 12 b. Pawls 24, being exposed in the sleeve's bore 12 a, can be acted upon by structures passing through the sleeve's bore.
Pawls 24 are normally biased to protrude into the inner bore 12 a 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.
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 24 a to their outboard ends 24 d. As such, the pawls can have a concave curvature along their front side surfaces and a convex curvature along their back side surfaces.
Each pawl has on its back side surface 24 c one or more pawl protrusions 32, for example, a plurality of which may be formed as ratchet teeth.
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.
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 34 a between two adjacent teeth. Because there are many teeth in the illustrated embodiment, there are many valleys 34 a. 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.
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 12 b. 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.
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.
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.
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 48 a and a lower part 48 b, 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.
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.
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 12 a. 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 24 c 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 34 a 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.
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 12 a.
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.
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.
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 26 a and these numbers can be lined up with a reference point, such as the stop tab, on the sleeve.
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 12 a.
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 12 a 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.
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.
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.
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.
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.
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.
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.
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.
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 626 a, 626 b therein.
The sleeve furthest downhole, sleeve 634, includes valve seat 626 b with a diameter D1 and the sleeve thereabove has valve seat 626 a 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.
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 626 b. 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 626 a, 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 626 a.
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.
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.
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.
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 plurality of extrudable packing elements. The methods may therefore, include setting packers about the tubular string and introducing fluids through the tubular string.
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.
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 716 a 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 716 b to 716 e 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 716 a to 716 e 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.
Initially, as shown in FIG. 6A, all ports are in the closed position, wherein they are closed by their respective sliding sleeve valves.
As shown in FIG. 6B, a ball 736 may be pumped onto a seat in the sleeve 716 a to open its port in Interval 1. A wellbore fluid treatment may be effected through the ports opened by sleeve 716 a. When the ball passes through the sleeves 716 c-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 716 b on that interval such that it can be shifted to the open position when desired.
Next, as shown in FIG. 6C, a ball 736 a is pumped onto the activated seat in sleeve 716 b 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 716 c from an inactive position to an active position so that it can be shifted to the open position when desired. When ball 736 a lands in sleeve 716 b 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 716 b.
Thereafter, as shown in FIG. 6D, a ball 736 b is pumped onto the activated seat in sleeve 716 c to open the port in Interval 3. When ball 736 b lands in sleeve 716 c, 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 716 c. When ball 736 b passes through the sleeve 716 e 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 716 d 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 716 d can be shifted to the open position when desired.
Thereafter, as shown in FIG. 6E, a ball 736 c is pumped onto the activated seat of sleeve 716 d to open the port in Interval 4 and a fluid treatment may be effect therethrough. When ball 736 c passes through Interval 5, it moves sleeve 716 e from inactive to active so that it can be shifted to the open position when desired.
Thereafter, as shown in FIG. 6F, a ball 736 d is pumped onto the activated seat of sleeve 716 e to open the port in Interval 5 completing opening of all ports.
With reference to the tool of FIGS. 1 to 4B, it is noted that sleeve 716 b 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 716 c 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 716 d and 716 e would be installed with their rings rotated to provide for three and four rotations, 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 736-736 d 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 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 716 a, 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.
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”.

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.