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.

Description

PRIORITY APPLICATION

This application claims priority to U.S. provisional application Ser. No. 61/703,138, 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 3 ¾″ ball, then the well treatment string will generally be limited to approximately eleven sleeves and, therefore, can treat in only eleven stages.

A tool with an indexing mechanism may permit a ball of one size to actuate a number of tools and thus permit a string to be employed with a greater number of zones.

SUMMARY OF THE INVENTION

In accordance with an aspect of the present invention, there is provided a wellbore tool comprising: a tubular housing including an upper end, a lower end, and a wall defined between an inner surface and an outer surface; a tool mechanism capable of being reconfigured from a first inactive position to an active position; an indexing mechanism for reconfiguring the tool mechanism, the indexing mechanism including an indexing sleeve including an inner bore, the indexing sleeve biased to move axially along the inner surface, and an inner sleeve positioned within the inner bore, the inner sleeve having an axial bore extending therethrough and a wall thickness, and a lever having first and second ends, the lever pivotally connected to the inner sleeve at a fulcrum and being pivotal through a slot in the inner sleeve to protrude at the second end into the axial bore, while the first end engages and stops axial movement of the indexing sleeve; and an actuator for passing through the axial bore and contacting the second end to drive the first end out of engagement with the indexing sleeve, thereby permitting axial movement of the indexing sleeve to move the tool mechanism from the first inactive position toward the active position.

In accordance with another aspect of the present invention, there is provided a wellbore sliding sleeve sub comprising: a tubular housing including an upper end, a lower end and a wall defined between an inner surface and an outer surface; a fluid port through the wall of the tubular housing; an inner sleeve having an axial bore and installed substantially concentrically in the tubular housing, the inner sleeve being axially slideable in the tubular housing at least from a first position covering the fluid port to a second position exposing the fluid port to fluid flow therethrough; a ball seat on the inner sleeve including a plurality of levers connected to the inner sleeve about a circumference of the wall, each of the plurality of levers including a first end, a second end and a pivotal connection to the inner sleeve between the first end and the second end, and each lever capable protruding at the second end into the axial bore while the first end extends radially outwardly of the inner sleeve, the ball seat being configurable from (i) an inactive position wherein the plurality of levers is capable of pivoting to collapse and allow passage of an actuator through the axial bore to (ii) an active position, wherein the plurality of levers is fixed against pivotal movement and remains protruding into the axial bore to catch a sleeve shifting device; and an indexing sleeve positioned substantially concentrically between the inner sleeve and the tubular housing, the indexing sleeve controlling the configuration of the ball seat between the active position and the inactive position, wherein the indexing sleeve is biased for axial movement along the tubular housing between a first position allowing collapsing of the plurality of levers and a second position supporting the plurality of levers in the active position.

In accordance with another aspect of the present invention, there is provided a method for actuating a downhole tool to an active condition, the method comprising: passing an actuator through a ball seat in the downhole tool to permit incremental movement of an indexing sleeve past the ball seat until the indexing sleeve moves to a final position wherein the ball seat is held by the indexing sleeve against collapsing, thereby configuring the ball seat in an active position to catch a sleeve shifting device conveyed through the string.

It is to be understood that other aspects of the present invention will become readily apparent to those skilled in the art from the following detailed description, wherein various embodiments of the invention are shown and described by way of illustration. As will be realized, the invention is capable for other and different embodiments and its several details are capable of modification in various other respects, all without departing from the spirit and scope of the present invention. Accordingly the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring to the drawings, several aspects of the present invention are illustrated by way of example, and not by way of limitation, in detail in the figures, wherein:

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 isometric view of an inner sleeve of the wellbore tool of FIG. 1;

FIGS. 3A, 3B, 3C and 3D, sometimes referred to collectively as FIGS. 3, are enlarged sectional views of the tool following from FIG. 1 showing sequential stages in the indexing cycle; and

FIG. 4 is a sectional view through the wellbore tool following after FIG. 3D, in an active position after all indexing cycles are completed;

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 FIGS. 6, are a series of schematic sectional views through a wellbore having positioned therein a fluid treatment assembly showing a method according to the present invention.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

The description that follows and the embodiments described therein, are provided by way of illustration of an example, or examples, of particular embodiments of the principles of various aspects of the present invention. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the invention in its various aspects. In the description, similar parts are marked throughout the specification and the drawings with the same respective reference numerals. The drawings are not necessarily to scale and in some instances proportions may have been exaggerated in order more clearly to depict certain features.

A wellbore tool that is actuable through a plurality of positions may include a tubular housing including an upper end, a lower end, and a wall defined between an inner surface and an outer surface; a tool mechanism capable of being reconfigured from a first inactive position to an active position; an indexing mechanism for reconfiguring the tool mechanism, the indexing mechanism including an indexing sleeve including an inner bore, the indexing sleeve biased to move axially along the inner surface, and an inner sleeve positioned within the inner bore, the inner sleeve having an axial bore extending therethrough and a wall thickness, and a lever having first and second ends, the lever pivotally connected to the inner sleeve at a fulcrum and being pivotal through a slot in the inner sleeve to protrude at the second end into the axial bore, while the first end engages and stops axial movement of the indexing sleeve; and an actuator for passing through the axial bore and contacting the second end to drive the first end out of engagement with the indexing sleeve, thereby permitting axial movement of the indexing sleeve to move the tool mechanism from the first inactive position toward the active position.

In operation, the tool may be employed in a wellbore operation wherein the tool is positioned in a well with the housing in a selected position, a force may be applied to an indexing mechanism of the tool to drive a tool mechanism through a plurality of positions, the applied force driving may be via an actuator passing through the tool while it is installed downhole. The actuator may be launched from surface. Passing the actuator through the indexing mechanism permits incremental movement of an indexing sleeve to take the indexing mechanism through an indexing cycle until the indexing sleeve moves to a final position wherein the tool is brought into an active position. The indexing mechanism includes a component protruding into the inner bore of the tool such that it can receive the applied force of the actuator passing therethrough. The indexing mechanism may include a lever. In one embodiment, the lever forms a ball seat that in the final position is held by the indexing sleeve against collapsing. In this position, it is active to catch a sleeve-shifting device.

Generally, a wellbore tool often has a tubular housing, which, having a tubular form, can pass readily through the wellbore as drilled. Also, tubular forms can be connected by threading into assembled tools or strings deployable into a well. The tool may be run into a well for temporary use or may be installed in a well for longer term use or reuse.

The wellbore tool may be a packer, an anchor, a sliding sleeve tool, etc. The form of the wellbore tool is determined by its tool mechanism. For example, a packer includes a tool mechanism including a packing mechanism with at least a set and an unset position, the packing mechanism may include an annular packing element, one or more compression rings, etc. The tool mechanism of an anchor includes an anchoring mechanism including at least a set and an unset position, the anchoring mechanism may include a plurality of slips, a slip expander, etc. A tool mechanism of a sliding sleeve tool includes a port and a sliding sleeve moveable to open and close the port. The sliding sleeve tool has at least a closed port position and an open port position. As another example, another sliding sleeve tool has a tool mechanism including a port, a sliding sleeve moveable to open and close the port and a seat for the sliding sleeve to allow plug actuation of the sliding sleeve and in such an embodiment, the sliding sleeve valve may include at least an activated seat position ready to catch a plug (such as a ball or other plug form that is sized to seal in the seat) and an inactive seat position wherein either the seat has not yet formed or the seat is in place but is collapsible such that the ball may pass through the seat.

The form of the tool determines the method that is carried out by the tool. For example, the method may include forming an annular seal, anchoring a tool, opening a port, etc.

The tools and methods of the present invention can be used in various borehole conditions including open holes, cased holes, vertical holes, horizontal holes, straight holes or deviated holes.

With reference to FIGS. 1 to 4, an example of a wellbore sliding sleeve tool 10 is shown that is modified by the passage therethrough of one or more actuators 11 that eventually configure an inner sleeve 12 of the tool to be drivable to an open position by a sleeve shifting device 14. While inner sleeve 12 can originally be configured not to be driveable, it can be modified by the passage of one or more actuators to be driveable. In particular, by passage of actuators 11, sleeve 12 can be configured such that during the subsequent passage of a sleeve shifting device 14, sleeve 12 may be actuated by the sleeve shifting device to shift open. The reconfiguration of the sleeve to be driven by a sleeve shifting device in this embodiment, includes the formation of a seat 16 in non-collapsible form after one or more actuations of the tool, as controlled by an indexing mechanism. For example, in one embodiment, the indexing mechanism may allow the tool to be advanced through a plurality of positions prior to placement in a position wherein the valve seat is actually configured in a non-collapsible way. As shown in the Figures, one or more actuators may each cycle the components of the indexing mechanism to advance one position, through one or more inactive (also termed passive) positions, before finally moving into an active position to form the final, non-collapsible valve seat 16.

In the drawings, FIG. 1 shows tool 10 in a run in position just about to be cycled by actuator 11 (in this embodiment actuator 11 is in the form of a ball); FIGS. 3A, 3B, 3C and 3D are sequential, enlarged, sectional views showing the tool moving through the stages of an indexing cycle, as driven by the same actuator 11; and FIG. 4 shows tool 10 in an active position, with sleeve 12 reconfigured such that seat 16 is formed in a non-collapsible way and inner sleeve 12 has been driven by a sleeve shifting device 14 (shown in phantom so as not to obstruct illustration).

The illustrated sliding sleeve tool includes a tubular housing 20 including an upper end 20a, a lower end 20b, an inner surface 20c defining an inner bore and an outer surface 20d. Although not shown, the sliding sleeve tool, may be formed as a sub with its tubular housing 20 having ends 20a, 20b threaded or otherwise formed such that it may be connected into a wellbore tubular string. The housing defines a long axis x extending through its ends 20a, 20b.

The sliding sleeve tool includes one or more ports 22 through the wall of the tubular housing where the port, when opened, provides access between the inner bore and outer surface 20d. The open and closed condition of port 22 is determined by sleeve 12. The sleeve is axially moveable in the tubular housing between a position overlying and closing port 22 (FIG. 1) and a position at least partially retracted from, and therefore opening, port 22 (FIG. 5).

Sleeve 12 includes an inner bore 12a and an outer surface 12b. The sleeve includes seat 16 in bore 12a. Seat 16 is capable of being configured through a plurality of positions including one or more inactive positions and an active position. In the inactive positions (FIGS. 1 to 3D) seat 16 is collapsible and allows any actuator, such as actuator 11, that lands therein to pass. In the active position (FIG. 4), seat 16 is configured in a non-collapsible way and is capable of catching and retaining sleeve shifting device 14. In particular, seat 16 in the active position cannot collapse and sleeve shifting device 14 that is sized to be larger than the uncollapsed ID of the seat will be caught in the seat and cannot pass through. Sleeve shifting device 14, therefore, lands in and creates a substantial seal with the seat. Thus, an axially directed force can be applied to sleeve 12 by fluid pressure through a piston effect created by device 14 in seat 16. The applied pressure can overcome any holding devices such as shear pins 17 and drives the sleeve to open.

Sleeve shifting device 14 and actuators 11 may be plugs such as balls, as shown, or other plug forms like darts, etc., that are launchable from surface and sized to have an outer diameter greater than the uncollapsed ID of seat 16. In this illustrated embodiment, both sleeve shifting device 14 and actuator 11 are balls. As shown here, actuator 11 may actually be identical to sleeve shifting device 14. However, the seat collapses when it is in an inactive configuration to let actuator 11 pass, while seat 16, when active, is configured to retain and create a substantial seal with sleeve shifting device 14, which explains the differing operations of the actuator and the sleeve shifting device. It is a benefit of the tool to be able to use the same size device 11, 14 to actuate a number of tools in the string.

The indexing mechanism includes one or more levers 24 and an indexing sleeve 26. The levers 24 protrude into the inner bore of sleeve 12 and creates a diameter restriction to sense the passage of an actuator. Herein, levers 24 also form seat 16 in the active position.

Levers 24 each include an upper end 24a and a lower end 24b and are each a primary lever. Being a primary lever, load on one end causes movement of the other end.

Levers 24 are each connected to sleeve 12 by a fulcrum pin 28, here in the form of shoulder bolts secured by end nuts 28a. Each fulcrum pin 28 connects its lever 24 such that the lever pivots about an axis y which extends the length of the pin, is positioned in the thickness of the wall of sleeve 12 and is substantially orthogonal to axis x. Each lever 24 is connected by pin 28 in a slot 30 formed through the wall of sleeve 12 such that, when pivoting, the ends 24a, 24b can protrude into inner bore 12a and beyond outer surface 12b. Levers 24 are exposed in sleeve inner bore 12a and can be acted upon by structures passing through the bore.

The levers are spaced apart about a circumference of sleeve 12 and effectively create a ring coaxial with sleeve 12.

Levers 24 may each have an upper rear protrusion 24a′ and a lower rear protrusion 24b′. In addition, the levers may each have a lower front protrusion 24b″. Protrusions 24a′, 24b′, 24b″ extend out beyond the surrounding lever surface to increase the thickness of the levers at their ends and, for example, to extend the reach of the levers at their ends. These protrusions may be shaped to facilitate operation of the levers.

While the illustrated tool includes four levers 24, more or fewer levers can be employed. However, there is some benefit in providing a plurality of levers substantially equally spaced apart about the sleeve's circumference so that any forces on the levers may be balanced about the circumference and there may be a back up to overcome a failure of one lever, since each lever may operate independently.

Indexing sleeve 26 is positioned concentrically between tubular housing 20 and sleeve 12. Sleeve 12 is positioned inwardly of the inner wall 26a of the indexing sleeve. Since the indexing sleeve encircles sleeve 12, the indexing sleeve 26 has a normal diameter D across its inner wall 26a that is greater than the outer diameter of the sleeve's outer surface 12b. The normal diameter may be just slightly greater than the outer diameter of the outer surface of sleeve 12. Indexing sleeve 26 includes a plurality of recesses 32 on its inner wall 26a. The recesses 32 are axially spaced apart along the wall of indexing sleeve with raised areas 33 therebetween separating the recesses. The raised areas have a diameter less than the recess diameter RD and greater than or equal to the normal diameter D. In the illustrated embodiment, recesses 32 are annular grooves separated by the raised areas and raised areas 33 are also annularly formed, such that the inner surface of the indexing sleeve has a ribbed surface contour with uniformly shaped, repeating ribs.

An end, support wall portion 34 of the indexing sleeve is devoid of recesses and is raised such that it defines an inner diameter less than the recess diameter RD and greater than or equal to the normal diameter D. The support wall portion is positioned at an end of the recesses. In this embodiment, the support wall is positioned adjacent the uppermost recess.

Indexing sleeve 26 is positioned in a space between tubular housing 20 and sleeve 12. The space is an annular recess between upper wall 40 and lower wall 42. Indexing sleeve 26 is biased to move axially along the annular recess, when it is free to do so. In the illustrated embodiment, sleeve 26 is biased to move toward lower wall 42. A spring 44 may be positioned between sleeve 26 and upper wall 40 to bias the sleeve toward lower wall 42.

Indexing sleeve 26 works with levers 24 to index the tool through a number of cycles of inactive positions before reaching the active position. Levers 24 normally bear against indexing sleeve 26. In particular, levers 24 normally extend through slots 30 to bear at their upper ends against inner wall 26a. When a lever 24 bears at upper end against indexing sleeve 26, the opposite end of the lever protrudes from slot 30 into inner bore 12a of sleeve 12. The indexing mechanism operation depends on the interaction of one end of each lever 24 against sleeve 26, while at the same time the opposite end of each lever protrudes into inner bore 12a of sleeve. The protrusion of the opposite ends of the levers into the sleeve's inner bore, allows the levers to be acted upon by a passing actuator.

During indexing, the levers are moved through a plurality of positions and as the levers are moved, the indexing sleeve, being constantly under a biasing force, moves incrementally axially along the annular space.

In the starting position (FIGS. 1 and 3A), levers 24 bear at their upper ends against sleeve 26. In particular, upper ends 24a are engaged in one of the recesses 32 on the inner wall of the indexing sleeve. Upper ends 24a, being engaged in one of the recesses 32, hold the indexing sleeve against the bias of spring and prevent indexing sleeve 26 from moving down. In this starting position, while upper ends 24a engage the indexing sleeve, lower ends 24b protrude into inner bore 12a and create a constriction less than the inner diameter of the sleeve and less than the diameter of an actuator 11 selected to work with those levers.

In a second position (FIG. 3C) of the indexing cycle, the levers have been rotated, arrows R (FIG. 3B), about their fulcrums such that lower ends 24b bear against indexing sleeve 26. Levers 24 may be moved from the starting position to this second position by an actuator bearing against the levers. When levers 24 are rotated, as by the actuator passing over the levers, upper ends 24a are pulled out of engagement with sleeve 26 and spring 44 is capable of moving sleeve 26 until lower ends 24b bear against indexing sleeve 26.

During indexing through the positions, the levers are moved, arrows R, between the starting position (FIG. 3A) and the second position (FIG. 3C). As noted, this pivoting movement is driven by an actuator 11 that has a diameter greater than the constricted diameter of the levers moving against and past the levers. An actuator moving downhole, arrow A, for example after being launched from above, lands against the protruding lower ends 24b of the levers and since the ends form a constriction less than the diameter of the actuator, the actuator pivots the levers to move past them, as shown in the sequence of FIGS. 3A-3C.

After passage of actuator 11, when the actuator clears the levers, the levers immediately return, arrows R2, from the second position to either (i) a next starting position (FIG. 3D), where upper ends 24a are again engaged against sleeve 26 to stop it, or (ii) the active position (FIG. 4), where levers 24 are stopped from further rotation,

In a next starting position, the ends 24a are placed into another recess and the sleeve is biased down to immediately engage protrusions 24a′ against wall 34a. For example, from FIGS. 3A to 3D, it can be seen that ends 24a move from recess 32I to 32II. If an end 24a hits against a raised area 33 during its pivotal movement along arrows R2, lever 24 won't stop movement of the sleeve 26. However, sleeve 26 continues to move down until end 24a can enter a recess and then end 24a engages in the recess and stops movement of the sleeve.

Eventually, the active position is reached (FIG. 4) where the levers are supported against support wall 34 of the indexing sleeve. In this active position, levers 24 are substantially stopped against rotation through slot 30 and they remain protruding into inner bore 12a to create a constriction which forms ball seat 16. Ball seat 16 has a diameter less than that across inner wall 12a and less than the diameter of sleeve shifting device, which herein is ball 14. In the illustrated embodiment, lower ends 24b form the ball seat, but upper ends 24a could alternately form the ball seat, depending on the shape of support wall 34 and the shape of ends 24a, 24b.

When the tool is indexed from an inactive position to the active position, the levers are moved from the starting position, to the second position and then into the active position. The passage of an actuator 11 moves the levers from the starting position to the second position and, once the actuator passes, the levers then move from the second position to the active position.

In the inactive, starting position, levers 24 hold the indexing sleeve against the bias in spring 44 and prevent sleeve 26 from moving axially down. However, levers 24 may be disengaged from the recess by passage of an actuator 11. Passage of an actuator strikes against lower ends 24b and causes the levers to rotate about their fulcrum pin 28. Since the levers hold the sleeve from being biased by spring 44, disengagement of the levers from the indexing sleeve allows the sleeve to be moved down. When moving from the second position back to the starting position or to the active position, upper ends 24a are returned to a position against the indexing sleeve. Whether the indexing cycle returns the tool to an inactive, starting position or moves the tool to the active position is determined by the structure of the indexing sleeve that has been moved by spring 44 behind the levers. In particular, the levers may be engaged in another recess 32 or they may be positioned against the end support wall portion 34.

The number of times that a lever is capable of cycling before arriving at the active position depends on the number of recesses into which upper end 24a can engage before reaching the support wall 34: that is, the number of recesses between the starting position recess 32I (in which the upper ends are first installed before run in) and the support wall 34. Thus, the number of axially spaced apart recesses 32 on sleeve 26 is at least one plus the number of inactive cycles through which the indexing system is intended to pass before reaching the active position. (i.e. the number of recesses required on sleeve 26 is the first one, in which the upper end of the lever is originally set, plus a number of recesses at least equal to the number of times that the tool is to be indexed before reaching the active position.) While, there may be more recesses than the number of times that the tool is intended to be indexed, the starting position of the lever will be selected as that recess below the total of the number of inactive cycles through which the indexing system is intended to pass before reaching the active position.

As noted, levers 24 normally bear at their upper ends against sleeve 26. The levers may each be biased, for example by a spring about fulcrum pin 28, to assume this position. Alternately, the shape of the levers and the indexing sleeve together with the action of spring 44, may be selected to urge the upper ends to bear against the sleeve. For example, lower rear protrusion 24b′ can include a ramped upper surface 24b′″ shaped to urge lever 24 to rotate along arrow R2. In particular, if lower rear protrusion 24b′ is positioned in a recess on the sleeve and sleeve 26 is urged down by spring 44, raised area 33 pushes against ramped upper surface 24b′″ and drives lower rear protrusion 24b′ out of the recess (FIG. 3C). This causes lever 24 to pivot, arrows R2, and bear at upper end 24a against sleeve 26. If this form of biasing is used, the indexing sleeve pushes against the ramped upper surface. For example, further raised areas 33 may be required on the indexing sleeve to push against surface 24b′″ and bias the lever, even if those further raised areas/recesses aren't used for engagement by upper end 24a. Thus, the indexing sleeve may include more recesses and raised areas than those used for engagement by the upper end of the lever, those additional recesses and raised areas being between the lower end of the indexing sleeve and the starting recess 32I.

The upper rear protrusion 24a′ and the recesses may be shaped to enhance the engagement between them. For example, the upper rear protrusion 24a′ and the upper walls 32a of the recesses may be angled with the upper rear protrusion 24a′ extending upwardly and the upper wall 32a extending at an acute angle relative to the base 32b of the recess. Thus, when upper rear protrusion 24a′ resides in a recess, the upper wall engages over the upper rear protrusion and upper rear protrusion 24a′ can only be disengaged from recess by urging sleeve 26 upwardly to effectively lift the upper wall off the protrusion. Thus, to pull upper ends 24a out of a recess, enough force must be applied to pull upper rear protrusion 24a′ against upper wall 32a and, thereby, move sleeve 26 upwardly against the bias in spring 44.

Support wall area 34 may have a form to support levers 24 in a position forming a constriction that is a non-collapsing seat. For example, while support wall 34 may take various forms, in the illustrated embodiment, it has a diameter that forces lower ends 24b out into the inner bore of sleeve 12 and supports them in this position. Also in the illustrated embodiment, support wall 34 is spaced from recesses 32 by a large groove 48. Large groove 48 has a diameter about equal to recess diameter RD and allows upper end protrusion 24a′ to be rotated toward sleeve 26 to allow lower end rear protrusion 24b′ to be rotated into the inner bore of sleeve to clear recesses 32 on the sleeve. Large groove 48 is axially long enough that the levers can rotate freely, until the recesses 32 are entirely pushed, by spring 44, past the lower ends of the levers. Thus, sufficient space is provided between recesses 32 and support wall 34 that only when lower end rear protrusion 24b′ is clear of the recesses, does support wall 34 come to underlie the levers,

Thus, in the illustrated embodiment, support wall area 34 is spaced from the upper most recess at least a distance equal to the length from protrusion 24a′ to protrusion 24b′.

In use, the tool is assembled with indexing sleeve 26 biased downwardly by spring 44 and sleeve 26 held against the bias in spring by levers 24 engaged in a recess in the indexing sleeve. Thus, indexing sleeve 26 is biased to axially move down relative to levers 24, but can only do so when freed from engagement with the levers.

Upper end 24a of each lever is engaged in a selected recess of the indexing sleeve. The recess in which the upper end is engaged is the one below a number of recesses equal to the number of times the tool is to be cycled through inactive positions. For example, with reference to FIG. 1, the tool requires five cycles through inactive positions before arriving at the active position and, thus, the lever upper end 24a is initially installed, as shown, at the 6^th recess 32I from the upper end. While upper ends 24a are engaged against sleeve 26, the lower ends 24b protrude into the inner bore of sleeve 12.

Sleeve 12, on which the levers are pivotally installed, is held stationary in the tool, as by shear pins 17.

The tool is then run into the wellbore.

During wellbore operations, actuators 11 are launched from above, such as from surface, to at least drive the tool through its inactive cycles. The actuators pass through the inner bore of sleeve 12. The actuators may serve other purposes in the well, if desired.

When an actuator 11 lands against ends 24b, the levers are rotated about their fulcrums as shown by arrows R. This causes the upper ends 24a to release engagement with the indexing sleeve. Upper ends 24a are pulled out of recess 32I. When upper ends 24a are pulled out of engagement with the indexing sleeve, spring 44 biases indexing sleeve 26 down relative to the levers.

When the levers pivot, ends 24b collapse radially out and actuator 11 can pass through. In so doing, ends 24b come to bear against the indexing sleeve and limit its axial movement. When actuator 11 has passed, the levers rotate back, arrows R2, such that upper ends 24a move back toward indexing sleeve 26 and ends 24a engage into the next recess 32II. Pivotal movement of lever back along arrows R2 can be driven by a raised area 33x striking the lower rear protrusion 24b′ and urging it out as force is applied against ramped surface 24b′″.

When upper end protrusion 24a′ is pivoted into the next recess 32II, the protrusion 24a′ engages wall 32a and again stops the indexing sleeve from shifting down.

This motion is repeated by each passing actuator (similar to actuator 11 but not shown) until upper end protrusion 24a′ is positioned in the upper most recess 32IV.

When upper end protrusion 24a′ is positioned in the upper most recess 32IV, the next actuator that passes through the levers frees the upper end protrusion 24a′ from recesses 32 and allows sleeve 26 to be biased all the way down until support wall 34 is positioned behind levers 24. Sleeve 26 moves freely as biased by spring 44 since upper protrusion 24a′ is beyond recesses 32 and bottom rear protrusion 24b′ cannot stop the movement of sleeve 26, as it does not have a surface formed for engaging walls 32a.

In this entire process, sleeve 12 that carries levers 25 remains axially stationary, while levers 25 pivot and indexing sleeve 26 moves axially outside of sleeve 12.

When sleeve 26 is positioned with support wall 34 behind levers 25, the levers cannot rotate and ends 24b″ protrude into inner bore 12a of sleeve. Indexing sleeve 26 may be locked in this position relative to sleeve 12, if desired, to stop any further movement of the indexing sleeve. For this purpose, a lock can be employed to lock indexing sleeve 26 to sleeve 12.

When a sleeve shifting device 14 is then launched from surface, it lands on the levers. Since levers 24 cannot collapse out of the way, device 14 is caught on the constriction formed by the levers, which now form seat 16. Force that is generated by fluid pressure acting against device 14 and that force is transferred to shear pins 17. Sufficient force causes pins 17 to shear and sleeve 12 can shift down to open the ports 22. Another lock, such as c-ring 50 may lock the sleeve 12 in the open port position.

As will be appreciated, the downhole tool can include various components for appropriate operations. For example, seals 60 may be positioned between sleeve 12 and housing 20 to prevent fluid leakage and bypass. Torque resistors 62 may be employed to control against rotation of the sleeves 12, 26 about axis x.

Likewise, a mode of construction may be employed that best configures the parts and/or facilitates construction. For example, it is noted that many parts are formed of interconnected subcomponents.

The tool illustrated in FIGS. 1 to 4 may be employed in a method to index a tool through a plurality of inactive positions before arriving at an active position. For example, the indexing mechanism can be set to undergo any number of cycles up to the maximum number of recesses 32 before arriving at the active position. The number of cycles may be selected based on the number of actuators that are intended to pass through the tool prior to the tool being configured into its active position for its main function.

In use, one or more of the tools with an indexing mechanism may be positioned in a tubing string. Because of their usefulness to increase the possible numbers of sleeves in any tubing string, the sliding sleeve tools may be installed above one or more sleeves having a set valve seat. For example, with reference to 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 levers and the other components of the indexing mechanism, which can be actuated to form a non-collapsible valve seat (shown not yet formed). The second and third sleeves may be reconfigurable or, as shown, standard sleeves, with a set valve seat 626a, 626b therein.

The sleeve furthest downhole, sleeve 634, includes valve seat 626b with a diameter D1 and the sleeve thereabove has valve seat 626a with a diameter D2. Diameter D1 is smaller than D2 and therefore sleeve 634 requires the smaller ball 623 to seal thereagainst, which can easily pass through the seat of sleeve 633. Indexing mechanism 638 of sleeve 632 includes a collapsible seat with an inner diameter D2.

This provides that the lowest sleeve 634 can be actuated to open first by launching ball 623 which can pass without effect through all of the sleeves 633, 632 thereabove but will land in and seal against seat 626b. Second sleeve 633 can likewise be actuated to move along tubing string 612 by ball 636, which is sized to pass through all of the sleeves thereabove to land and seal in seat 626a, so that pressure can be built up thereabove. However, in the illustrated embodiment, although ball 636 can pass through the sleeves thereabove, it may actuate those sleeves, for example sleeve 632, to generate valve seats thereon. For example, when ball 636 passes sleeve 632, the ball catches in actuating mechanism 638 and cycles the sleeve from one notch for an inactive position to a next notch for an active position and forms a non-collapsible seat. For example, actuating mechanism 638 on sleeve 632 includes the collapsible seat with a diameter D2 and is formed to be axially moved by ball 636 passing thereby cycle the indexing mechanism and create the non-collapsible seat. However, ball 636 does pass through sleeve 632 and the ball can continue to seat 626a.

Of course, where the first sleeve, with the configurable valve seat, is positioned above other sleeves with valve seats formable or fixed thereon, the formation of the valve seat on the first seat should be timed or selected to avoid interference with access to the valve 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 720a-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 716a-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 collapsible seats that are formable to non-collapsible seats when actuated to do so by use of an indexing mechanism for movement of the seat between inactive positions where the seat is collapsible and an active position where the seats is activated and formed in a non-collapsible manner. For example, the seats of sleeves 716a to 716e may be similar to seat 16 as shown in 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 716a to open its port in Interval 1. A wellbore fluid treatment may be effected through the ports opened by sleeve 716a. When the ball passes through the sleeves 716c-e in Intervals 5, 4, and 3, they make a passive shift from one inactive recess position to a next inactive recess position. When the ball passes through Interval 2, it moves the indexing mechanism to support the levers against pivoting at the support wall and a non-collapsible ball stop is formed on sleeve 716b on that interval such that it can be shifted to the open position when desired.

Next, as shown in 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. 613 and a wellbore fluid treatment may be effected through the ports opened by sleeve 716b.

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 moving from one inactive recess position to a next inactive recess position. When the ball passes through Interval 4, it moves sleeve 716d from inactive to active, for example, with support wall positioned behind the levers, so that sleeve 716d can be shifted to the open position when desired.

Thereafter, as shown in 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 effected therethrough. When ball 736c passes through Interval 5, it moves sleeve 716e from inactive to active so that it can be shifted to the open position when desired.

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 the opening of all ports.

With reference to the tool of FIGS. 1 to 4, it is noted that sleeve 716b of Interval 2 would be installed with the lever in the upper most recess 32VI, such that after one actuation thereof (i.e. after one ball passes therethrough), the indexing sleeve would move to position with support wall 34 behind levers 24 to form seat 16 in a non-collapsible configuration. Likewise, the sleeve 716c of Interval 3 would be installed with its lever upper ends 24a in the recess next to recess 32VI, such that after two actuations thereof (i.e. after two balls pass therethrough), the indexing sleeve would move to support the levers and the seat would be activated in a non-collapsible form. The other sleeves 716d and 716e would be installed with their levers engaging the third and fourth recesses, respectively.

When the ports are each opened, the formation accessed therethrough can be stimulated as by fracturing. It is noted, therefore, that the formation can be treated in a focused, staged manner. It is also noted that balls 736-736d may all be the same size, but still this portion of the formation can be treated in a focused, staged manner, through one port at a time. Note that while only five ports are shown in this segment of the string, more than five ports can be run in a string. The intervals need not be directly adjacent, as shown, but can be spaced and there can be more than one port/sleeve per interval (i.e. at least two ports in one interval that open after the same number of actuations or which open in sequence). Further similar series of ports could be employed above and/or below this series, which use other sized balls. Of course, any sleeves below that use a different sized ball will use a smaller ball that can pass through the illustrated sleeves without actuating them.

This system and tool of FIGS. 6A to 6F allows a single sized ball or other plug to function numerous valves. The sleeves may sense the passing of a ball by the indexing mechanism. As shown by sleeve 716a, the system can use combinations of solid ball seats and sleeves with indexing mechanisms. The system allows for installations of fluid 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 comprising:

a tubular housing including an upper end, a lower end, and a wall defined between an inner surface and an outer surface;

a tool mechanism capable of being reconfigured from a first inactive position to an active position;

an indexing mechanism for reconfiguring the tool mechanism, the indexing mechanism including an indexing sleeve including an inner bore, the indexing sleeve biased to move axially along the inner surface, and an inner sleeve positioned within the inner bore, the inner sleeve having an axial bore extending therethrough and a wall thickness, and a lever having first and second ends, the lever pivotally connected to the inner sleeve at a fulcrum and being pivotal through a slot in the inner sleeve to protrude at the second end into the axial bore, while the first end engages and stops axial movement of the indexing sleeve; and

an actuator for passing through the axial bore and contacting the second end to drive the first end out of engagement with the indexing sleeve, thereby permitting axial movement of the indexing sleeve to move the tool mechanism from the first inactive position toward the active position.

2. The wellbore tool of claim 1 wherein the fulcrum is positioned between the first and second ends.

3. The wellbore tool of claim 1 wherein the indexing sleeve includes a plurality of axially spaced apart recesses and the lever engages in the recesses to stop movement of the indexing sleeve.

4. The wellbore tool of claim 3 wherein the indexing sleeve includes a support wall axially spaced from the plurality of axially spaced apart recesses, the support wall acting to restrict pivotal movement of the lever when the indexing sleeve is axially moved to position with the support wall behind the lever.

5. The wellbore tool of claim 1 wherein the inner sleeve is secured in the tubular housing to remain stationary until the tool mechanism is reconfigured to the active position.

6. The wellbore tool of claim 1 wherein the tool mechanism is a ball seat on the inner sleeve and in the active position, the ball seat is non-collapsible.

7. The wellbore tool of claim 6 wherein the lever forms the ball seat when the indexing mechanism moves the tool mechanism into the active position.

8. The wellbore tool of claim 6 wherein the inner sleeve covers a port through the wall of the tubular housing and in the active position, the ball seat allows the inner sleeve to be moved by a sleeve shifting device to open the port.

9. The wellbore tool of claim 6 wherein the ball seat in the inactive position is collapsible.

10. The wellbore tool of claim 1 wherein movement of the indexing sleeve drives pivotal movement of the lever to position the first end back into engagement with the indexing sleeve after the actuator passes the lever.

11. A wellbore sliding sleeve sub comprising: a tubular housing including an upper end, a lower end and a wall defined between an inner surface and an outer surface; a fluid port through the wall of the tubular housing; an inner sleeve having an axial bore and installed substantially concentrically in the tubular housing, the inner sleeve being axially slideable in the tubular housing at least from a first position covering the fluid port to a second position exposing the fluid port to fluid flow therethrough; a ball seat on the inner sleeve including a plurality of levers connected to the inner sleeve about a circumference of the wall, each of the plurality of levers including a first end, a second end and a pivotal connection to the inner sleeve between the first end and the second end, and each lever capable protruding at the second end into the axial bore while the first end extends radially outwardly of the inner sleeve, the ball seat being configurable from (i) an inactive position wherein the plurality of levers is capable of pivoting to collapse and allow passage of an actuator through the axial bore to (ii) an active position, wherein the plurality of levers is fixed against pivotal movement and remains protruding into the axial bore to catch a sleeve shifting device; and an indexing sleeve positioned substantially concentrically between the inner sleeve and the tubular housing, the indexing sleeve controlling the configuration of the ball seat between the active position and the inactive position, wherein the indexing sleeve is biased for axial movement along the tubular housing between a first position allowing collapsing of the plurality of levers and a second position supporting the plurality of levers in the active position.

12. The wellbore sliding sleeve sub of claim 11 wherein the plurality of levers controls movement of the indexing sleeve between the first position and the final position.

13. The wellbore sliding sleeve sub of claim 11 wherein the first end of each lever is formed to engage the indexing sleeve and movement of the indexing sleeve is permitted when the plurality of levers is driven pivotally to collapse.

14. The wellbore sliding sleeve sub of claim 13 wherein the plurality of levers is driven pivotally to collapse by passing an actuator through the axial bore.

15. A wellbore fluid treatment string comprising a string and a 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.

16. A method for actuating a downhole tool to an active position, the method comprising: passing an actuator through a ball seat in the downhole tool to permit incremental movement of an indexing sleeve past the ball seat until the indexing sleeve moves to a final position wherein the ball seat is held by the indexing sleeve against collapsing, thereby configuring the ball seat in an active position to catch a sleeve shifting device conveyed through the string.

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 forcing the actuator against levers that form the ball seat and, thereby, driving the levers out of engagement with the indexing sleeve as the actuator passes over the levers; and moving the levers back into engagement with the indexing sleeve when the actuator clears the levers.

19. The method of claim 16 wherein during passing, the actuator is shielded from contact with the indexing sleeve.

20. The method of claim 16 further comprising launching a sleeve-shifting device to catch in the ball seat and applying fluid pressure to apply a force against the ball seat,