Sliding Sleeve Valve and Shifting Tool Therefor

A sliding sleeve valve comprises a sliding sleeve having an internal profile along the length thereof, wherein the internal profile has a length that is less than the length of the sleeve and wherein the profile is adapted to engage a sleeve shifting tool. A sleeve shifting tool comprises sleeve engagement arms, for engaging a sliding sleeve of a sliding sleeve valve, wherein the sleeve engagement arms are hydraulically driven by a reciprocally rotating mandrel. An indexing tool allows rotation of the shifting tool to be achieved by axially moving a work string.

FIELD OF THE DESCRIPTION

The following description generally relates to devices for controlling fluid flow into and out of tubing strings used in hydrocarbon wells. More particularly, the present description relates to sliding sleeve valves used in tubing strings. The description also relates to shifting tools for selectively opening and closing such sleeve valves.

BACKGROUND

In the field of hydrocarbon production, a wellbore is drilled into a hydrocarbon-containing subterranean formation, and a tubing string, or production tubing, is then provided within the wellbore for providing fluid communication from the formation to the surface. The tubing string may in some cases be cemented within the wellbore. Tubing strings comprise a plurality of generally axially (i.e. end to end) connected tubular elements, along with any number of tools, or “tool subs”, also provided coaxially as part of the tubing string. Such tools include valve subs (discussed further below), packers, and others. Many other tools would be known in the art.

Typically, a tubing string used for hydrocarbon wells is provided with a plurality of ports or openings at desired locations or sections along its length, which are adapted to allow fluids to flow into or out of the tubing string. For example, in the case of a fracking operation, a high-pressure fluid is injected into the subterranean formation through ports in the tubing (and through the cement lining if present) to create fractures in the formation. Once the pressure applied to the formation is reduced, these fractures allow hydrocarbon materials in the formation to be released. Thereafter, the released hydrocarbons are “produced” by allowing the materials to flow into the tubing string through the ports, and ultimately brought to the surface. The equipment used for such production operations would be known to persons skilled in the art.

In view of the length of such strings and/or in view of permeation and other differences in subterranean formations into which the wells are drilled, it is often necessary to provide some means of controlling the flow out of or into the tubing string. For this purpose, it is common to have valves on the ports provided on tubing strings so that fluid flow is restricted to one or more desired locations there-along. For example, in the case of fracking, it is desirable to only create fractures at discrete locations in the formation along the length of the tubing string. Similarly, in the case of production, it is desirable to close or shut off one or more ports along the tubing string where fluids such as water, gas, etc., are preferentially produced over oil. For this purpose, it is common to utilize valves comprising sliding sleeves that are coaxially incorporated in the tubing string and which serve to cover, or close the ports provided on the string. Such “sliding sleeve valves” comprise a generally tubular sub having a sleeve slidably provided within a housing, with the housing being adapted to form part of the tubing string. The sliding sleeves are adapted to be axially moveable, in relation to the housing, between a “closed port” position, where the sleeve covers the ports, and an “open port” position, where the sleeve is moved away from the port, thereby allowing the port to form a channel through the tubing string. Consequently, the port (or ports), once opened, create a channel to allow fluid communication between the interior of the tubing string and the reservoir across the tubing string wall. In many cases, the sliding sleeve valve comprises a separate tubular sub or tool that is connected, end to end, to adjacent tubular members, thereby forming a part of the tubing string. Although the ports mentioned herein are indicated as being provided on the tubing string, it will be understood the ports are typically provided on the sub comprising the sliding sleeve valve.

Various methods are known for moving the sliding sleeves of sliding sleeve valves to open/or close the port(s) provided thereon. In one example, the sleeve may be provided with a region of reduced internal diameter to form “seat” for sealingly engaging a ball that is dropped into the tubing string from the surface. Once the ball is seated, fluid pressure within the tubing string upstream of the ball is increased, thereby causing the sleeve, initially in the closed port position, to slide in the downstream direction and thereby open the port(s). Another means of moving the sliding sleeves involves the use of a sleeve shifting tool. Such shifting tools are typically provided on a work string, such as coiled tubing, and are run downhole through the tubing string. When the shifting tool reaches a location near a selected sliding sleeve, the tool may be actuated and manipulated to engage the sliding sleeve. The shifting tool is then moved axially within and with respect to the tubing string, thereby causing the sliding sleeve to be axially moved with respect to the tubing string. The sleeve is moved to expose (open) or cover (close) the ports associated with the sleeve. While some shifting tools are designed for only unidirectional movement of the sliding sleeve, i.e. to either open or close ports, other tools are capable of sliding the sleeve in either direction, to either open and/or close the ports.

One example of a known bidirectional shifting tool is described in U.S. Pat. No. 9,638,003, which discloses a valve sub comprising a sliding sleeve as discussed above. The sleeve is provided within a cylindrical body, which is adapted to be connected to adjacent tubular members of a tubing string. The sliding sleeve has a constant inner diameter and opposing ends and is retained within the cylindrical body by means of retaining, or snap rings, which engage corresponding grooves provided on the inner surface of the cylindrical body. US '003 also discloses a shifting tool having hydraulically actuated sleeve engaging members for engaging the opposite ends of the sleeve and to move same with respect to the tubular body. In operation, the shifting tool is run downhole to the location of the sliding sleeve and actuated to engage and thereafter move the sliding sleeve. Axial movement of the sleeve is limited by annular shoulders provided in the cylindrical body. The shoulders also act on the shifting tool to disengage the sleeve once the shifting tool encounters the shoulders.

A further sliding sleeve actuator is described in US 2017/0058644.

With many of these known actuation or shifting tools, accurate engagement with the sleeve is often difficult to achieve. Similarly, with many of the known shifting tools, another problem that is faced relates to premature disengagement of the sleeve prior to achieving a fully open or fully closed position. In either case, the efficiency of the fracking or production operation is reduced and, in some cases, jeopardized. As a result, the entire tubing string may need to be extracted and a new tool run in, resulting in lost productivity and increased costs.

A need exists for an improved sliding sleeve valve and/or an improved shifting tool for sliding sleeves.

SUMMARY OF THE DESCRIPTION

In one aspect, the present description provides a sliding sleeve valve having a sliding sleeve with a profile portion of a lesser length than the sleeve and which is adapted to engage a shifting tool.

In another aspect, the present description provides a hydraulically actuated shifting tool for engaging and moving a sliding sleeve of a sliding sleeve valve, wherein the shifting tool comprises sleeve engaging arms that are reversibly extendable and a mandrel for driving the sleeve engaging arms.

In one aspect, there is provided a sliding sleeve valve for a tubing string, the valve comprising a generally tubular structure having a longitudinal axis and a first connecting end and a second connecting end, the first and second connecting ends being connectable to tubing string components, the valve comprising:

a first sub, having a first end comprising the first connecting end and a second end;

a second sub, having a first end comprising the second connecting end and a second end;

a generally cylindrical housing extending between the first and second subs and having first and second ends, and a wall having an interior surface; and,

a generally cylindrical sliding sleeve coaxially located within the housing and having first end facing the first sub second end and a second end facing the second sub second end;

wherein:the housing first end is connected to the first sub second end, and the housing second end is connected to the second sub second end;the housing wall includes at least one port for providing fluid communication through the wall; and,the interior surface of the wall has a profile defining at least first and second circumferential grooves provided at spaced separate locations along the longitudinal axis;the sliding sleeve is slidable, with respect to the housing, along the longitudinal axis of the valve;sliding of the sliding sleeve within the housing is limited by the first sub second end and the second sub second end;the sleeve is slidable between a closed port position, where the sleeve covers the at least one port, and an open port position, where the sleeve does not cover the at least one port;the sleeve has an inner surface with a region with reduced internal diameter, wherein the length of the region of reduced internal diameter is less than the length of the sleeve and wherein the region of reduced internal diameter defines a cross-sectional profile, the profile having opposed shoulders; and,the sleeve includes a locating means adapted to engage the first groove or second groove, wherein the locating means is engaged within the first groove when the sleeve is in the closed port position and wherein the locating means is engaged within the second groove when the sleeve is in the open port position.

In another aspect, there is provided a shifting tool for shifting a sleeve of a sliding sleeve valve, the shifting tool comprising a generally cylindrical body having a lumen and a longitudinal axis, the shifting tool comprising:

two or more sleeve engagement arms provided on the cylindrical body, wherein:the sleeve engagement arms comprise elongate elements having longitudinal axes generally parallel to the longitudinal axis of the cylindrical body;each of the sleeve engagement arms having opposed ends pivotably connected to the cylindrical body, whereby the arms are radially extendable away from the cylindrical body and reciprocate between a retracted position and an extended position;each of sleeve engagement arms having a pair of spaced apart sleeve engagement fingers provided on opposite ends thereof, each pair of sleeve engagement fingers defining a sliding sleeve engagement space there-between;

an elongate mandrel having a longitudinal axis and extending generally coaxially through the cylindrical body, wherein:the mandrel is rotatable about its axis within the cylindrical body;the mandrel includes a first portion connected to a rotation means; andthe mandrel is provided with pivot linkages for pivotably connecting with each of the sleeve engagement arms;a force transferring means, for transferring rotational motion of the mandrel to extend the at least two arms between the retracted and extended positions.

In another aspect, there is provided an indexing tool for rotating a tool provided on a work string. The indexing tool being actuated with an axial force and causing rotation of the other tool along its longitudinal axis.

In another aspect, a means of actuating a sliding sleeve valve is provided, wherein the sliding of the sleeve is controlled and monitored.

DETAILED DESCRIPTION

As used herein, the term “sub” will be understood to mean a tubing string component, such as a tubular member, a coupling, a tool etc. as known in the art. As also known, a sub has a generally cylindrical structure and is adapted to be connected to adjacent tubular members, or other subs, to form the tubing string. As with typical tubular members, a sub may have a female or “box” end and a male or “pin” end. The box end includes an internal threaded portion that is adapted to receive and threadingly engage an external thread provided on a pin end of an adjacent component (e.g. a tubular member, a sub, or a tool etc.). In this way, all components of the tubular string are connected together in an end to end manner.

The term “tool” as used herein will be understood to refer commonly known tubing string components that are used for performing various tasks. Examples of tools include valves, such as sliding sleeve valves, packers, and the like.

The term “port” will be understood to mean an opening, aperture, or the like, that is provided to allow the flow of fluid therethrough. As used herein, a port comprises an opening provided on the wall of a tubular body for forming a fluid channel into the lumen of the body.

The terms “comprise”, “comprises”, “comprised” or “comprising” may be used in the present description. As used herein (including the specification and/or the claims), these terms are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not as precluding the presence of one or more other feature, integer, step, component or a group thereof as would be apparent to persons having ordinary skill in the relevant art. Thus, the term “comprising” as used in this specification means “consisting at least in part of”. When interpreting statements in this specification that include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as “comprise” and “comprised” are to be interpreted in the same manner.

The term “and/or” if used herein can mean “and” or “or”.

Unless stated otherwise herein, the article “a” when used to identify any element is not intended to constitute a limitation of just one and will, instead, be understood to mean “at least one” or “one or more” unless indicated otherwise.

The terms “top”, “bottom”, “up”, or “down” may be used herein. It will be understood that these terms will be used purely for facilitating the description and, unless stated otherwise, are not intended in any way to limit the description to any spatial or positional orientation. In one example, the terms “top” or “uphole” may be used herein to refer to a direction along the tubing string or component towards the surface. Similarly, the terms “bottom” or “downhole” may be used herein to refer to a direction along the tubing string or component towards the bottom of the well, i.e. away from the surface.

Sliding Sleeve Valve

A sliding sleeve valve according to an aspect of the present description is illustrated inFIGS. 1ato 1c(collectively, “FIG. 1”) andFIGS. 2 to 6. As shown, the sliding sleeve valve10comprises a generally tubular body that comprises a first or top sub12, comprising a box end, and a second or bottom sub14, comprising a pin end. As would be understood the top sub12and bottom sub14are designed to connect to adjacent components of a tubing string. For this purpose, the top sub12and bottom sub14include suitable connecting means for connecting to such adjacent components. For example, each of subs12and14may, as is common, include threaded portions to form a pin and box connection with adjacent tubular components, other tools, or couplings etc. Although the top sub12and bottom sub14are described as having box and pin ends, respectively, it will be understood that these ends may be opposite and may be the same or different. The present description is not specific to any particular end configuration.

The sliding sleeve valve10also comprises a generally tubular housing, or barrel16, provided between the top sub12and bottom sub14and adapted to be connected thereto. As shown inFIGS. 2 to 6, the components of the sliding sleeve valve10combine to form the aforementioned generally tubular body, having a bore or lumen18extending therethrough.

As shown inFIG. 1, the housing16has a first end20adapted to connect to the top sub12and a second end22adapted to connect to the bottom sub14. In one aspect, each of the first end20and second end22comprise “box”-type structures, namely, structures having internal threads that are adapted to threadingly engage external threads of the top and bottom subs, respectively. In this way, one end of the top sub12is provided within the lumen of the housing16to form a first shoulder24within the bore18. Similarly, one end of the bottom sub14is provided within the lumen of the housing16to form a second shoulder26within the bore18. The purpose of the shoulders24and26is discussed further below.

The housing16includes one or more ports28that are provided proximal to one end thereof. As shown inFIGS. 2 to 6, the housing16include a plurality of circumferentially arranged ports28that are provided proximal to the second end22thereof. It will be understood that the present description is not limited to any particular number of ports.

The sliding sleeve valve10further comprises a sliding sleeve, or “sleeve” or “piston”30slidably provided within the bore of the housing16. The sliding sleeve30has a length defining a first end32and a second end34. As illustrated inFIGS. 2 to 6, travel of the sleeve30within the housing16is limited by contact between the first shoulder24against the sleeve first end32, or by contact between the second shoulder26against the sleeve second end34.

The sleeve30includes a thickened region defining a region of the sleeve30having a reduced internal diameter and thereby a radially inward raised profile36, defined by first and second sleeve shoulders,38and40, respectively. The inward profile36, and in particular the shoulders38and40, serve as catches by being adapted to engage a shifting tool for effecting movement of the sleeve30(as discussed further below). It will be understood that the shoulders38and40may be provided with a square or angular (i.e. bevelled) geometry to aid in engaging the shifting tool. As noted, the profile36preferably has a shorter length than the length of the sleeve30, thereby resulting in the sleeve30having end first and second sections50and52, that extend away from the profile36. As shown, first end section50extends from first shoulder38and second section52extends from second shoulder40. This arrangement of the sleeve30components results in a functional advantage in that a shifting tool would not need to engage the entire length of the sleeve30in order to effect movement of same. This advantage of the sleeve30will be more apparent in the following description.

The inner surface of the housing16includes a first groove42and a second groove44, each of which is adapted to receive and removably engage a retaining means, such as a snap ring46or the like provided on the sleeve30. The first groove42is positioned proximal to the ports28, while the second groove44is positioned axially away from the ports28, in a direction towards the top sub12. The snap ring46is designed to be biased in a radially outward direction from the sleeve30so as to facilitate engagement with one of the grooves42or44provided on the housing16. In one preferred aspect, the snap ring46may be provided within a recess48provided on the outer surface of the sleeve30. Thus, as would be understood, as the sleeve30is axially moved within the housing16, the snap ring46is received within one of the grooves42or44and an additional force would be required to dislodge the sleeve, where such additional force serves to compress the snap ring46thereby allowing disengagement from the respective groove (42,44).

As shown inFIGS. 2 to 6, the grooves42and44are adapted to receive the snap ring46(or any similar mechanism), and thereby positively locate the sleeve30within the housing16until a force is applied to move the sleeve to a different axial position. As noted above, the total axial movement of the sleeve30within the housing16is limited to a region bounded by the first shoulder24and second shoulder26.

It will be understood that, while a snap ring46is discussed herein, the retaining means may be any device that functions to retain the sleeve30generally in position within the housing16when such retaining means is engaged within one of the grooves. As such, the retaining means may comprise a dog, an outwardly biased spring mechanism or any other similar device. Similarly, although grooves42and44may be a preferred structure, it will be understood that any other means may be used to receive and retain the snap ring46or other such retaining means. For example, where, as illustrated, the retaining means comprises a snap ring, a continuous groove may be best to retain the former. If the retaining means comprise dogs or outwardly biased pistons or the like, the groove may alternatively comprise detents or other such structures. The present description is not limited to any particular retaining means. However, for convenience, the term “snap ring” will be used herein in reference to element46and the term “groove” will be used in reference to elements42and44.

As illustrated inFIGS. 2 to 4, when the snap ring46is received within the first groove42of the housing16, the sleeve30is located proximal to the bottom sub14and is in a position where it overlaps the ports28and thereby closes same. Thus, when the snap ring46is retained or received within the first groove42, the sleeve30, and therefore the sleeve valve10, is in the “closed position”, whereby fluid flow through the ports is prevented or at least limited.

As illustrated inFIGS. 5 and 6, when the snap ring46is received within the second groove44, the sleeve30is located proximal to the top sub12and no longer covers or overlaps the ports28. Thus, when the snap ring46is retained or received within the second groove44, the sleeve30, and therefore the sleeve valve10, is in the “open position”, whereby fluid flow communication between the interior and exterior of the housing14, through the ports28, is possible.

As illustrated inFIGS. 2 to 6, the first and second grooves,42and44, provided on the housing16, are preferably sized to be wider than the snap ring46. As will be more apparent in the further discussion below, with this arrangement, the snap ring46is permitted a limited amount of movement within either of the grooves42or44. This therefore translates to the sleeve30being permitted to travel a limited axial distance with respect to the housing16while the snap ring46is retained in either of the grooves42and44. The widths of the grooves42and44are sized so that the freedom of movement of the snap ring46retained therein allows the sleeve30to travel a given distance while still maintaining the sleeve valve10in a desired port open or port closed position. For instance, as shown inFIGS. 3 and 4, although the sleeve30overlaps, and therefore closes, the ports28, the snap ring46is still able to move within the groove42in an axial direction from the bottom sub14towards the top sub12. Similarly, as shown inFIGS. 5 and 6, the valve10is maintained in a port open position while the snap ring46is able to axial travel within the second groove44.

As will be appreciated, and according to the preferred aspect described herein, by sizing the grooves42and44to be wider than the snap ring46, a functional advantage is realized since, as shown inFIGS. 3 to 6, in order to move the sleeve from the fully closed position, as shown inFIG. 3, to the fully open position as shown inFIG. 6, the sleeve30passes through two intermediate stages, which serves to signal to the shifting tool operator that the sleeve has been fully extended or retracted. This signalling feature aids in ensuring that the sleeve is properly shifted into the desired open or closed positions. This is illustrated by the movement of the sleeve30from the fully closed position (shown inFIG. 3) to the fully open position (shown inFIG. 6) using a shifting tool (not shown). In particular, once a shifting tool (not shown) is run downhole and actuated to engage the sleeve30in the fully closed position, as shown inFIG. 3, the shifting tool is moved axially in an uphole direction, i.e. in a direction from the bottom sub14towards the top sub12. Initially, the operator of the shifting tool will not encounter much resistance as the snap ring46travels within the first groove42. Once the snap ring46reaches the end of the groove42, as illustrated inFIG. 4, further movement of the sleeve30is impeded and a greater force is required to axially move the sleeve30. This increased resistance signals to the operator that the snap ring has reached the upstream end54of the groove42. This position of the sleeve30is referred to herein as the “snapped closed”, or intermediary closed position, where the snap ring46remains retained within the first groove42and the ports28remain closed. In order to further advance the sleeve30in the upstream direction (i.e. towards the top sub12), a sufficient tension or force must be applied to the shifting tool to force the snap ring46beyond the upstream end54of the first groove42, and thereby out of the groove42, and to move it towards the direction of the second groove44. At this point, the operator notices the increase and rapid decrease in the required pulling force required for the shifting tool, signalling that the sleeve30has left the “snapped closed” position and is proceeding to the open position. At this point, the ports28are not fully open. Subsequently, as illustrated inFIG. 5, the snap ring46eventually enters the second groove44and the force required to pull the shifting tool reduces. Thus, the operator becomes aware that the sliding sleeve30has been moved into the “snapped open”, or intermediary open position. As seen inFIG. 5, in the snapped open position, the ports28are open and no longer covered by any portion of the sleeve30. Further pulling of the shifting tool is possible, in view of the clearance between the width of the groove44and the width of the snap ring46, until the first end32of the sleeve30abuts the first shoulder24of the top sub12, as illustrated inFIG. 6. At this point, no further axial movement of the sleeve30in the uphole direction is possible and the lack of movement of the sleeve30and increased force requirement of shifting tool signals to the operator that the sleeve is now in the “fully open” position (FIG. 6). As will be understood, the reverse occurs as the sleeve is moved from the fully open position (FIG. 6) to the fully closed position (FIG. 3).

Thus, as will be understood from the above discussion, an operator of the shifting tool is clearly able to determine when the sleeve10is moved from the closed to open or open to closed positions in view of the two-stage signal that is provided. This mitigates against a single signal being misinterpreted as an opening or closing of the sleeve when in reality the sleeve or the shifting tool is simply stuck due to interference with debris or friction etc. As discussed above, when the sleeve valve10is used, the operator is clearly advised when the sleeve reaches the fully closed or fully open position. As will be appreciated, the ability of the sleeve valve10to effectively signal the open and closed position to the operator is not dependent upon the use of any specific shifting tool. That is, although a preferred shifting tool is described herein, other shifting tools may also be used with the sleeve valve10while still providing the same two-stage signalling advantage.

As discussed above, the sleeve valve10is provided as an assembly comprising four primary sections: the top sub12, the bottom sub14, the housing16and the sleeve30. As will be understood, this offers the advantage that, in assembling the valve10, the sleeve30, with the snap ring loaded46thereon, can first be inserted into the housing16and the top and bottom subs,12and14, can then be attached to the housing16. As noted above, the opposing ends of the subs12and14, respectively, form the shoulders24and26. In another aspect, one of the top sub12or bottom sub14may be formed with the housing16as a unitary structure. In such case, the aforementioned shoulder24or26would need to be formed within such structure for the purpose noted above.

As illustrated inFIGS. 2 to 6, and as would be understood by persons skilled in the art, the sleeve valve10will include necessary seals to avoid leakage of fluids. For example, one or more seals58may be provided at a connection between the top sub12and the housing16. Similarly, one or more seals60may be provided at a connection between the bottom sub14and the housing16. Further, seals62,64,66and68may be provided along the length of the sleeve30to form seals between the sleeve30and the housing16. In particular, as shown, at least one seal62is provided proximal to the first end32and at least one seal68is provided proximal to the second end34of the sleeve30. Two further seals64and66are provided at a region corresponding to the profile36, preferably proximal to the ends thereof.

As would be understood, the seals mentioned above preferably comprise O-rings, which are commonly used for tubing string tools. However, other equivalent sealing devices may also be used as would be apparent to persons skilled in the art. Generally, seals such as those discussed above, are provided in grooves having a depth that is less than the diameter of the seals. As shown inFIGS. 2 to 6, such grooves are provided on the exterior surfaces of the top sub12, bottom sub14and sleeve30, as is typical.

In one aspect, the edge24of the top sub12is preferably provided with a bevel70directed away from the sleeve30. Similarly, the edge26of the bottom sub14is preferably provided with a bevel72also directed away from the sleeve30. As discussed further below, the bevels70and72aid in disengaging the shifting tool from the sleeve30.

Shifting Tool—Sleeve Engagement Portion

In one aspect, the present description provides a shifting tool for moving a sliding sleeve, such as, but not limited to, sleeve30of sleeve valve10discussed above. Thus, such shifting tool is used to open and/or close ports provided on the sleeve valve, such as ports28discussed above. As will be understood by persons skilled in the art, shifting tools as described herein are generally adapted to be inserted through the tubing string to the location of a selected sleeve valve, where they are actuated and thereby act upon the sleeve to move it axially with respect to the tubing string. This movement of the sliding sleeve was illustrated in the description above. Typically, shifting tools are run in the tubing string from surface using a work string, such coil tubing and the like. The shifting tools are therefore adapted to be connected to a work string and, optionally, to be connected to other work string components (such as other tools etc.)

A shifting tool according to an aspect of the present description is shown inFIGS. 7 to 9. As shown, the shifting tool100comprises a generally cylindrical and elongate body, with a longitudinal axis, and having a top end102, which, when in use, faces in the uphole direction, and a bottom end104, which, when in use, faces in the downhole direction. As shown inFIG. 9, the top end102includes a box portion106having an internal thread. The bottom end104includes a pin portion108having an external thread. As will be understood, the box portion106is adapted to threadingly engage a pin portion of a work string (e.g. coil tubing) component, while the pin portion108is adapted to threadingly engage a box portion of another work string component. It will also be understood that the box and pin portions mentioned above may also be reversed or the shifting tool100may be provided with two box or two pin portions. In the latter instance, it would be common for the shifting tool to be connected to at least one coupling or the like. It will also be understood that in some instances the shifting tool100may form the bottom or terminal end of a work string, in which case the pin portion108may comprise some other configuration.

In a preferred aspect, the shifting tool100comprises an assembly of a number of tubular components, or “subs”, joined together in a known manner. For example, as shown in the accompanying figures, the shifting tool100may comprise a driver sub110, a mid sub112, a retainer sub114and a sleeve engagement sub116. It should be noted that the nomenclature used for these tubular components is not intended to limit the scope of the description in any way. The functions of these subs are discussed further below.

The top end of the shifting tool100may comprise a top crossover sub118and the bottom end of the shifting tool may comprise a bottom crossover sub120. As will be understood, and as shown in the accompanying figures, the top and bottom crossover subs,118and120, provide the box and pin means, respectively, for connecting the shifting tool100to other components of the work string. The individual subs of the shifting tool100may be secured together in a variety of ways. In the aspect shown in the present figures, this is achieved using a number of set screws, such as those shown at122, and/or pins, such as those shown at124. The top crossover sub118would be generally open to the lumen of the coil tubing or other component of the work string (not shown).

The shifting tool100comprises a number of sleeve engagement arms which, as described below, are adapted to engage a sliding sleeve such as sleeve30described above when the shifting tool is actuated. As illustrated for example inFIG. 11, the shifting tool100according to one as aspect as described herein preferably includes two, i.e. first and second, sleeve engagement arms shown at126and128, which, in a preferred aspect, are generally circumferentially equidistantly spaced apart. Thus, in one aspect as illustrated, the first and second sleeve engagement arms126and128are circumferentially spaced apart by 180 degrees over the circumference of the shifting tool100. It will be understood from the present description that such circumferentially equidistant spacing is preferable for engaging a sleeve but that such spacing is not essential. Any other spacing or arrangement will be apparent to persons skilled in the art. As will be understood, the present description is also not limited to only two sleeve engagement arms and any number of such arms may be provided. For the present purposes, two arms may be suitable in view of diameter restrictions on the shifting tool100. Thus, for larger diameters, more than to of the sleeve engagement arms may be provided.

Each of the sleeve engagement arms126and128include a pair of sleeve engagement fingers, axially spaced apart on each respective arm. In one aspect, each pair of sleeve engagement fingers is provided generally at opposite ends of the respective sleeve engagement arm. For instance, as illustrated in the accompanying figures, first and second sleeve engagement arms126and128each include respective first sleeve engagement keys, or fingers130and134, provided at the “top” or uphold ends of arms126and128, proximal to the retainer sub114. The sleeve engagement arms126and128also include respective second sleeve engagement keys, or fingers132and136, which are provided at the “bottom”, or downhole end of the arms, axially spaced apart from the first sleeve engagement fingers in a direction towards the bottom crossover sub120. As shown, the first sleeve engagement fingers,132and136, are generally on a common transverse plane, whereby the fingers are generally at the same axial distance along the length of the shifting tool100. The second sleeve engagement fingers132and136are similarly arranged. In this way, and as illustrated for example inFIGS. 13, 15, 17, and 19-21, a sleeve engagement space is formed between the respective first and second fingers. This arrangement will be more apparent in the description provided below.

The sleeve engagement arms126and128are connected to the shifting tool100by hinges so as to allow the arms to be radially extended. In particular, first sleeve engagement arm126is attached to the shifting tool100by means of hinges138and140and the second sleeve engagement arm128is attached to the shifting tool100by means of hinges142and144. As shown in the accompanying figures, the hinges138,140,142, and144allow the arms126and128to be radially extended away from the longitudinal axis of the shifting tool100. In particular, and as illustrated, the hinges allow the arms126and128to swing about an axis that is at least generally parallel to the longitudinal axis of the shifting tool100. By way of example,FIGS. 13, 14, and 19show the shifting tool100with the arms126and128in the retracted position, whereasFIGS. 15, 16, and 20show the arms126and128in the extended position. The hinges138,140,142, and144may be of any structure that allows the arms126and128to swing in the manner described above. For example, as shown, the hinges may be formed by providing a slot in each of the arms126and128for receiving a respective tongue provided in a non-moving portion of the shifting tool100. A dowel pin or other similar retaining means may be provided through the slot and through the tongue to allow the two portions to swivel with respect to each other.

The first and second sleeve engagement arms126and128are also associated with a first actuating mechanism for effecting the aforementioned extension and retraction. In particular, and according to one aspect, the first sleeve engagement arm126includes first and second links146and148generally provided in a spaced apart manner along the length of the arm126. Similarly, the second sleeve engagement arm128includes first and second links150and152that are also generally provided in spaced apart manner along the length of the arm128. As shown, for example, inFIGS. 19, 20 and 21, the links,146,148,150, and152have a first end connected to the respective arm,126or128. The opposite ends of the links146,148,150, and152are connected to respective knuckles, wherein link146is connected to knuckle154, link148is connected to knuckle156, link150is connected to knuckle158, and link152is connected to knuckle160. Both ends of the links146,148,150, and152are connected in a moveable manner whereby, as shown, the ends of the links are rotatable about an axis that is generally parallel to the longitudinal axis of the shifting tool100. For this purpose, the ends of the links may be connected to the respective arms,126or128, or the respective knuckles, by means of dowel pins, screws, or any other similar mechanism that would allow for the aforementioned movement. By way of example, as shown inFIG. 11, a first end of link146is connected to the knuckle154by means of a machine screw162and the second end of link146is connected to the first sleeve engagement arm126by means of machine screw164. The other links,148,150, and152are preferably connected in a similar manner.

The knuckles154,156,158, and160are connected to a first rotating mandrel166that is provided within the sleeve engagement sub116and which extends longitudinally therein. The first rotating mandrel166generally comprises a tubular body having a longitudinal axis that is generally parallel with, and preferably coaxial with, the longitudinal axis of the sleeve shifting tool100. The first rotating mandrel is also adapted to rotate about its longitudinal axis within the sleeve engagement sub116and with respect to both the sub116and the sleeve shifting tool100itself. However, the first rotating mandrel166is fixed in position axially within the shifting tool100.

The knuckles154,156,158, and160are functionally connected to the first mandrel166in such a manner that rotation of the first mandrel166about its longitudinal axis (i.e. axial rotation) imparts a circumferential force on the knuckles. For this purpose, and as shown inFIG. 11, the first mandrel166may be provided, at least at certain locations, with a profiled outer surface, such as a hexagonal or octagonal profile. The knuckles in turn may be provided with a connecting ring, such as connecting ring168provided on knuckle154, wherein the connecting ring has a complementary inner profile and is adapted to fit over the first mandrel166, to form an interlocking arrangement there-between. As will be understood, with this arrangement, once the connecting ring168is provided over the first mandrel166, the complementary profiles prevent relative rotation there-between. Further, with this arrangement, upon rotation of the first mandrel166, a rotational force will be imparted to the connecting ring168and, in the result, a circumferential force is applied to the link146. It will be appreciated that while the aforementioned hexagonal outer profile and connecting ring arrangement may be preferred in terms of ease of assembly (since the various components can be inserted over others), the knuckles may be connected to the first mandrel in any other means for achieving the same result. For example, the connecting rings may be secured to the first mandrel166to achieve the same result, without the need to provide the aforementioned complementary profiles. Alternatively, the mandrel may be provided with a number of keys on the outer surface thereof and the ring may be provided with complementary grooves to receive such keys. All of the knuckles described above may be connected to the first mandrel166in the same manner as knuckle154.

FIG. 11also illustrates another preferred aspect, wherein both of knuckles154and158, associated respectively with the first and second sleeve engagement arms126and128, are connected to a common connecting ring168. As will be appreciated, in this way, rotation of the first mandrel166imparts simultaneous rotational force against both of knuckles154and158. In a similar manner, the knuckles156and160may also be connected to a common connecting ring170, in turn connected to the first mandrel166. While the use of a common connecting ring for two knuckles is described, it will be appreciated that the same simultaneous rotational force from the first mandrel166can be transmitted in any other manner. For example, the knuckles may comprise separate connecting rings, or other such connecting means, wherein the adjacent connecting means are joined or secured together. As will be appreciated, the present description is not restricted to any particular force translating mechanism between the first rotating mandrel and the knuckles.

As discussed above, upon rotation of the first rotating mandrel166, a rotational force is applied to connecting rings attached to the knuckles and, in turn, this is translated to a circumferential force that is applied to the links146,148,150and152. The links in turn transmit this circumferential force to the first and second sleeve engagement arms126and128. As will be understood, since the forces applied to the arms126and128stem from the rotation of the first mandrel166, such forces would ultimately be generally equal. In other words, with this above-described arrangement a generally equal circumferential force is applied to both sections of the arms126and128connected to the respective links and, moreover, such force is applied simultaneously.

As the circumferential force is applied to the arms126and128, circumferential movement of the arms is inhibited by the respective hinges,138,140and142,144. As a result, the unhinged portions of the arms126and128, that is, the portions having the fingers130,132,134, and136, are extended radially outward as illustrated, for example, inFIGS. 13 to 17. In particular, this radially outward movement results in the radially outward extension of the fingers130,132,134, and136, thereby resulting in the extended position of the arms are shown inFIGS. 15 and 16, for instance. This position may be referred to also as the extended, or sleeve engagement position, of the shifting tool100, as discussed below.

As shown inFIGS. 9 and 10, a bottom end of first rotating mandrel166(that is, the end adjacent the bottom end104of the shifting tool100) of the sleeve engagement sub116extends partially into a hub172provided on the bottom crossover sub120. The bottom crossover sub120is connected to the sleeve engagement sub116and is maintained stationary with respect to same. To allow rotation of the first rotating mandrel166within the bottom crossover sub120, the hub172is provided with a bearing means, as would be known to persons skilled in the art. For example, such bearing means may comprise a number of ball bearings174provided within a groove or other known ball bearing retaining means that would be known to persons skilled in the art. As will be understood, the ball bearings facilitate rotation of the first rotating mandrel166within the hub170. It will also be understood that any number of seals, such as O-rings176, as shown inFIGS. 9 and 10may be employed to establish a fluid seal between the bottom crossover sub120and the sleeve engagement sub116. It will be understood that similar seals may be employed between other sections of the shifting tool100.

As shown inFIGS. 9 and 10, a top end of the first rotating mandrel166(that is, the end adjacent the top end102of the shifting tool100) extends through the retainer sub114and into the mid sub112. The first rotating mandrel166is allowed to rotate with respect to both the retainer sub114and the mid sub112. In this regard, one or both of the retainer sub114and mid sub112may be provided with a bearing means for allowing rotation of the first mandrel166therein. In one example, the bearing means may comprise a number of ball bearings such as shown at178and/or roller bearings such as shown at179. Various other bearing means will be known to persons skilled in the art.

As will be understood, the present description is not limited to any particular means for retaining the first rotating mandrel166is the desired position and for allowing rotation of same within the sleeve shifting tool100.

As mentioned above, actuation of the shifting tool100into the extended position is achieved by rotation of the first mandrel166. As discussed below, such rotation of the first mandrel166is caused by the action of the driver sub110, which is shown in detail inFIGS. 9, 10, 13, 15, and 17. As shown, a bottom end of the driver sub110is connected and secured to a top end of the mid sub112. In one aspect, the top end of the mid sub is provided within the lumen of the driver sub110so as to form a shoulder180therein. The connection between the driver sub110and the mid sub112may be preferably sealed using any known means. For example, one or more O-rings182may be utilized for forming the seal(s) between the sub110and sub112.

The driver sub110generally comprises a cylindrical barrel having a bore generally coaxial with the shifting tool100. Within the bore of the driver sub110is provided a generally cylindrical insert184, which is provided proximal to a top end of the driver sub110, that is, the end of the driver sub110proximal to the top end102of the shifting tool100. The insert184is secured in place within the driver sub110and prevented from moving axially therein. The insert184comprises a bore that is coaxial with the bore of the driver sub110, wherein the insert184has a top end that opens to the lumen of the top crossover sub118and thereby into the lumen of the coil tubing or other work string. The insert also includes a bottom end186having a reduced internal diameter, forming a shoulder within the bore of the insert184. A first piston188is provided within the insert184and is reciprocally slidable therein. The first piston188has a body that extends through the bottom end186of the insert184and a top end190that is provided proximal to the top end of the insert184. The top end190of the first piston188has an external diameter that is greater than the internal diameter of the bottom end186of the insert184. Thus, as shown for example inFIGS. 13, 15, 32, and 33, although the body of the first piston188is able to move axially and reciprocally with respect to the insert184, axial movement of the first piston188in a direction from the top end to the bottom end of the shifting tool100is inhibited upon the top end190of the first piston188contacting the bottom end186of the insert, which is the position illustrated inFIG. 15.

The driver sub110further includes a second piston192comprising a generally cylindrical body having a top end and a bottom end and a bore extending there-through. The top end of the second piston192comprises radial flange194defining a region reduced internal diameter. As can be seen inFIGS. 10, 13, 15, and 17, for example, the body of first piston188is slidably provided within bore of the second piston and the bottom end of the first piston is provide with a radial flange196defining a region of the body of the first piston having a larger outer diameter. As shown, the outer diameter of the flange196of the first piston188is greater than the inner diameter of the flange194of the second piston192. In this way, axial separation of the first piston and second piston is prevented.

The driver sub110further includes a second rotating mandrel198provided proximal to the bottom end thereof. One aspect of the mandrel198is illustrated in isolation inFIGS. 36 and 37. As with the first rotating mandrel166, the second rotating mandrel also comprises a generally tubular body having a longitudinal axis that is generally in line with the longitudinal axes of the first rotating mandrel166and the driver sub110(i.e. of the shifting tool100). The second rotating mandrel198, as with the first rotating mandrel166, is axially fixed in position within the shifting tool100, although the second rotating mandrel198is allowed to rotate about its longitudinal axis. The bottom end of the second rotating mandrel198is connected to the top end of the first rotating mandrel166, whereby rotation of one of the mandrels results in a corresponding rotation of the other mandrel. As will be discussed further below, when in use, the second rotating mandrel196generally drives the rotation of the first rotating mandrel166. As will be understood, the link or connection between the two mandrels,166and198, may take any form as known in the art to achieve this purpose. In one aspect, as illustrated inFIGS. 9 and 10, the two mandrels may be linked in a box and pin arrangement and secured to each other using a set screw, such as200, a pin or any other such connection means. It will be understood that the present description is not limited to any particular means for connecting the mandrels166and198together.

The top end of the second rotating mandrel198is received within the lumen of the second piston192. For this purpose, the bottom end of the second piston192may be provided with a flange202that has an outer diameter that is adapted to slidably contact the bore of the driver sub110to provide stability. The flange202has an inner diameter that slidably contacts the second rotating mandrel198and allows rotation of the second mandrel198therein.

The bottom end of the second piston192is also provided with one or more (i.e. at least one) guide pins204that are fixed in position with respect to the second piston192. In this regard, the guide pins204may be received within apertures205or other such openings provided on the outer surface of the second piston192. The guide pins204are adapted to be received within corresponding spiral or helical grooves206provided on the outer surface of the second rotating mandrel198and at the top end thereof. As will be understood, at least one guide pin204will be provided for each groove206. In view of this arrangement, as the second piston192is axially advanced towards the bottom end of the shifting tool, it will be understood that the guide pins204, engaged within the grooves206, will impart a rotational force on the second rotating mandrel198as they are moved along the respective groove. It will be understood that, for this purpose, the second piston192is arranged so as to be incapable of axial rotation while being axially advanced within the driver sub110. In one aspect, the reciprocal stroke of the second piston192may be constrained by a groove or track etc. (not shown) provided in wall of the driver sub110, in which case the second piston192may be provided with a suitable key or the like (not shown) to engage the groove or track.

The second rotating mandrel198is illustrated in isolation inFIGS. 36 and 37so that the grooves206can be more easily seen. In the aspect shown, the mandrel198is provided with three generally helical grooves206that are generally circumferentially equidistantly spaced. As discussed above, in a preferred aspect, at least one guide pin204is provided to engage with a respective groove206. Thus, for the version illustrated in the present figures, since three grooves206are provided, there would preferably be at least three guide pins provided as well. In the aspects illustrated in previous figures, the second rotating mandrel198has a solid wall without any opening there-through. In the aspect illustrated inFIGS. 36 and 37, the second rotating mandrel198includes optional apertures240extending through the body of the mandrel198. These apertures are believed to improve the flow dynamics of the fluid flowing through the tool and aid in maintaining the tool in the desired actuated state.

Axial movement of the second piston192in the direction towards the bottom end104of the shifting tool100is limited by a flange208provided within the lumen of the driver sub110. As shown for example inFIG. 15, the inner diameter of the flange208of the driver sub110is a smaller than the outer diameter of flange194provided on the top end the second piston192. As such, axial movement of the flange194beyond the flange208of the driver sub110is prevented. While the term flange has been used herein, it will be understood that such flanges are not necessarily continuous and may comprise a number of radial protrusions.

Both the first piston188and the second piston192are biased in a direction towards the top end102of the shifting tool100. In one aspect, such biasing is achieved by means of springs. As illustrated, a first spring210serves to axially bias the first piston188and a second spring212serves to axially bias the second piston192. The first spring210is provided between the top end190of the first piston188and the radial flange194provided at the top end of the second piston192. Thus, the first spring210axially biases the first piston188away from the second piston192. As also shown in the accompanying figures, the first spring210may be provided coaxially over the body of the first piston188. The second spring212is provided between the flange202of the second piston192and the shoulder180of the mid sub112. Thus, the second spring212axially biases the second piston192away from the mid sub112. Although reference is made herein to “springs”, persons skilled in the art will understand that any other biasing means may be used to achieve the same purpose, such as hydraulic systems etc. Springs, such as coiled springs, are however preferred given the geometries of the tool.

In view of the above description, it will be appreciated that as the first piston188is advanced towards the bottom end104of the shifting tool100, it applies an axial force on the second piston192, which in turn is advanced towards the bottom end104. In view of the engagement between the guide pins204of the second piston192and the grooves206of the second rotating mandrel198, it will be understood that such axial advancement of the second piston198imparts a rotational force on the second mandrel198. Rotation of the second mandrel198in turn results in axial rotation of the first rotating mandrel166. As discussed above, rotation of the first rotating mandrel166causes the sleeve engagement arms126and128to be extended, whereby the shifting tool100is actuated into the extended, or sleeve engaging position. The movement of the aforementioned components is illustrated by comparingFIGS. 13 and 15or inFIGS. 19 and 20, for example.

Although the present description refers to two separate mandrels166and198that are connected together, it will be understood that the shifting tool described herein may also comprise a single mandrel having the features of the two aforementioned mandrels incorporated therein. The use of two mandrels may be preferred for ease of assembly.

For advancing the first piston188, and thereby actuating the shifting tool100, hydraulic pressure may be applied from surface through the coil tubing or other work string components to which the shifting tool100is attached. For this purpose, the first piston188is provided with a top, or uphole facing piston head214that is sealed against the insert184(as discussed further below). The piston head214, and therefore the first piston188, is adapted to be advanced axially towards the bottom end104of the shifting tool100once a sufficient pressure is applied through the work string to overcome the biasing force of the second spring212. In the result, the sleeve shifting tool100is put into the extended state as shown for example inFIG. 15. Once the pressure is released, the second spring212forces the shifting tool100to return to the retracted position as shown for example inFIG. 13.

The piston head214is shown in more detail inFIGS. 32 and 33. As shown, the piston head comprises an opening in the top end of the first piston188. Within the opening is positioned a nozzle226for providing a restriction to the flow of fluid through the shifting tool100. The nozzle226is received within a recess225provided at the top of the first piston188and is held in position with a retaining means, such as a snap ring227or the like. The nozzle is sealed against the wall of the recess225by means of a resilient seal229, which may for example comprise an O-ring or the like. As illustrated inFIGS. 32 and 33, the seal229is preferably retained within a groove provided on the outer surface of the nozzle226.

In one aspect, the nozzle226comprises an orifice plate as shown inFIGS. 32 and 33(and earlier figures), which is commonly known. As would be understood, as pressure is increased in the work string (e.g. the coiled tubing) to which the shifting tool is attached, such pressure acts upon the orifice plate nozzle226and imparts a downward force thereon. When such force exceeds the biasing force of the spring212, movement of the first piston188results.

FIGS. 34 and 35illustrate another aspect of the nozzle described above. In this aspect, the nozzle, shown as226a, comprises an elongated body having a passage extending therethrough that has a converging-diverging geometry. As shown inFIGS. 34 and 35, this aspect of the nozzle,226a, has an inlet230and an outlet232. Proximal to the inlet is provided a throat228, which forms a constriction in the passage. In this way, the passage between the inlet and the throat reduces in diameter thereby forming a converging section. Downstream of the throat228, the diameter of the passage gradually expands, forming the diverging portion of the passage. The geometry of the nozzle226ais believed to reduce the turbulence of fluid flowing therethrough and thereby achieve more predictable actuation of the shifting tool when needed.FIGS. 34 and 35also illustrate, at231, a groove, as described above, provided on the outer surface of the nozzle for retaining a seal229. As would be understood, a nozzle such as226amay require a larger recess225in first piston188. Such accommodations would be understood by persons skilled in the art.

As mentioned above, the first piston188is preferably sealed against the insert184. Such seal is illustrated inFIGS. 32 and 33, for example, at234and236, which, in one aspect, comprise resilient seals, such as O-rings, that are provided on the outer surface of the first piston. As will be understood, seals such as234and236serve to ensure that fluids passing through the work string are diverted through the nozzle alone. As would be known in the art, seals234and236are retained within respective grooves provided on the outer surface of the first piston188, as shown inFIGS. 32 and 33.

Similarly, a seal, such as shown at238is provided between the insert184and the inner surface of the driver sub110.

In one aspect, the shifting tool100may optionally include a filter216or the like to prevent debris etc. from entering the shifting tool100. As noted, only certain figures, such asFIGS. 10, 13, 15, and 17, illustrate this optional aspect of the description.FIGS. 9, 19, 20, and 21, for example, illustrate the same shifting tool100without the optional filter216.

Operation of Shifting Tool

In operation, the sleeve shifting tool100, in the retracted state, is run down-hole and positioned at a region where a sliding sleeve valve is located and where such valve is to be manipulated into an open or closed position. The shifting tool in this retracted state is shown for example inFIGS. 13, 19, and 30. When positioned in the desired location, the shifting tool100is actuated by increasing pressure as described above, and the arms126and128are thereby extended into the extended state as shown for example inFIGS. 15, 20, and 31. In the extended state, the shifting tool100is able to engage a sliding sleeve within the sleeve engagement space formed between the pairs of keys, or fingers (i.e.130and132, and134and136), provided on the arms126and128. It will be understood that for such engagement to occur, the sleeve being shifted would include some engagement means provided thereon. In one example, the sleeve may have a smaller internal diameter than the housing carrying the sleeve. In such case, the opposed ends of the sleeve would extend into the lumen of the sleeve valve and would therefore provide surfaces that can be engaged within the sleeve engagement space of the shifting tool100, as described above. A sleeve of this type is described, for example, in U.S. Pat. No. 9,638,003. Thus, the shifting tool described herein may be applied to known sleeve valves.

Once the sleeve shifting tool100is actuated and engages a sliding sleeve, the shifting tool100is advanced axially towards the top102or bottom104directions. Once the sleeve encounters a limiting means, such as a shoulder provided on the sliding sleeve valve, further advancement of the shifting tool100forces the arms126and128inwards in a direction towards the retracted state. However, such inward force applied to the arms126and128would be counteracted by the hydraulic pressure applied to the tool100. To accommodate such further advancement, the first spring210allows the second piston198to be axially advanced towards the first piston188, to thereby result in the shifting tool being placed into a “back driven” position as illustrated inFIGS. 17 and 21. As will be understood, in this position, the shifting tool100may be axially moved to the location of a further sliding sleeve valve, at which point, the tool100will automatically return to the extended position to allow engagement with another sliding sleeve. Thus, a series of sliding sleeves may be opened or closed without adjusting the pressure applied to the shifting tool100.

To assist the movement of the sleeve shifting tool100from one sliding sleeve valve to another, the fingers of the sleeve engagement arms126and128are preferably provided with bevels facing the top102and bottom104ends of the shifting tool. For example, the fingers130and134, provided on the top ends of the sleeve engagement arms126and128, are preferably provided with respective bevels218and220. Similarly, fingers132and136, provided on the bottom ends of the sleeve engagement arms126and128, are preferably provided with respective bevels222and224.

As will be understood, when the sleeve shifting tool100is moved to the back-driven position, the added force required to axially advance the shifting tool100would be sensed by the operator at surface. This would therefore signal to the operator that the shifting tool100is being moved between sleeve valves.

Combination of Sleeve Shifting Tool and Sliding Sleeve Valve

The combination of the sleeve shifting tool100and the sliding sleeve valve10described herein offers a unique advantage over known sleeve shifting apparatuses. In particular, the present description provides a sliding sleeve valve10, such as that described above, wherein an internal profile36is provided on the sleeve30, and a shifting tool100that is adapted to engage such profile.

Referring toFIGS. 22 and 26, the sleeve shifting tool100is shown in its retracted position and in a position adjacent a sliding sleeve valve10. As will be understood, the portion of the tubing string illustrated in these figures is provided in a horizontal well and, therefore, the shifting tool100, having a smaller diameter than the lumen of the valve100, typically rests on the lowermost portion thereof.FIG. 22also illustrates a preferred aspect of the present description wherein the sleeve engagement space, formed between the respective fingers of the sleeve engagement arms126and128, is longer than the length of the profile36. As will be understood, this respective configuration assists in positioning of the shifting tool100in the required position. That is, since the engagement space for the sleeve is larger than the profile36, a degree of clearance is permitted between the relative position of the shifting tool100and the sleeve30. This feature will be more apparent in the following description.

FIGS. 23 and 27illustrate the sleeve shifting tool100in its extended position (i.e. the position shown inFIG. 16). As discussed above, this position of the shifting tool100is achieved by applying hydraulic pressure to the work string to which the shifting tool100is attached and thereby actuating the shifting tool as discussed above. As can be seen, the shifting tool100may be positioned at a general location near the profile36and actuated so as to extend the fingers130,132,134, and136of the sleeve engagement arms126and128so that the pairs of fingers130,132and134,136are provided on opposite ends of the profile36of the sleeve30. This is referred to herein as the extended or sleeve engagement position of the tool100. As discussed above, the sleeve engagement space between the respective pairs of fingers is longer than the profile36and, as such, the tool100does not need to be positioned with a high degree of accuracy. After actuation, the sleeve shifting tool is moved until the one of the sets of fingers engages a shoulder of the profile36. In the example illustrated inFIGS. 23 to 25 and 27 to 29, the sleeve30is being shifted in the up hole (or top102) direction in order to open the ports28on the sliding sleeve valve10. Thus, after actuating the shifting tool100, and engaging the profile36of the sleeve within the sleeve engagement space, the shifting tool100is moved in the up-hole direction until the fingers132and136contact the bottom facing shoulder40of the profile36. This position is shown inFIG. 23, which also shows the snap ring46engaged within first groove42of the sleeve valve10. Subsequently, the sleeve shifting tool100is urged in the up-hole direction by applying increasing force until the snap ring46is force into the recess48provided in the sleeve30, as described above. Pulling of the shifting tool100is continued until the snap ring46enters into the second groove44. At this point, the operator senses a reduction in the pulling force require to move the shifting tool100. As described above, this position is referred to as the “snapped open” position and is illustrated inFIG. 24. Further advancement of the sleeve30is permitted in the up-hole direction owing to the width of the second groove44, as also discussed above.

When the shifting tool100is advanced further up hole, the bevels218and220on the fingers130and134, respectively, contact the bevel70provided on the top sub12of the sleeve valve10. At this point, further advancement of the shifting tool100requires additional force in order to compress the second spring212and thereby force to shifting tool100into the back-driven position. Such additional force requirement is sensed by the operator. This event also signals to the operator that the sleeve valve10has entered into the fully open state and that the shifting tool100is being moved away from the sleeve valve10and towards an adjacent sleeve valve. The sensed force will be reduced when the shifting tool is returned to the extended position, which occurs when the profile of the adjacent sleeve enters into the sleeve engagement space of the shifting tool100.

As will be understood, and as discussed above, the shifting tool100could also be used to move the sleeve30from the open to the closed port position using the shifting tool100by moving such tool in the opposite direction.

Indexing Tool

In certain applications, and particularly in the case of horizontal wells, it is common for the interior of the tubing string to contain sand and/or other debris from the formation. In such case, the operation of known shifting tools in often impaired by the debris interfering with the engagement between the shifting tool and the sliding sleeve. As many of the shifting tools are run in with coiled tubing, it is often difficult to reposition the shifting tools to achieve the desired engagement. In such cases, the desired sleeve is either not actuated or the work string is withdrawn and repositioned. As will be understood, this results in considerable delays and added expense to the well operations.

As would be understood, the shifting tool described herein provides an improved design over known tools that allows an operator to more accurately engage and move a desired sleeve. However, if the amount of debris in the tubing string is great, the operation of the presently described shifting tool may also be impaired. For example if a sufficient amount of debris is collected on the bottom of the tubing string at the region of a sliding sleeve, some of the keys or fingers,130to136, described above may be blocked from engaging the sleeve.

To address the above-mentioned issue, the present description provides an indexing tool that allows a shifting tool to be axially rotated while in situ, thereby allowing a unique means of repositioning the shifting tool without extracting the work string from the tubing string.

FIG. 38illustrates the shifting tool100described above, where like elements are identified with like reference numerals. The shifting tool100is connected to other elements of the work string, some of which are illustrated. In particular, at the uphole end of the shifting tool, there is provided a swivel body400that is connected to the top crossover sub118. As would be known to persons skilled in the art, a swivel sub permits axial rotation of a string component. In the present case, the swivel sub400serves to permit the shifting tool to rotate about its longitudinal axis with respect to the uphole portion of the work string. The purpose of this rotation is described further below.

Downhole of the shifting tool100is provided an indexing tool402, which comprises a main body404, comprising a generally tubular housing for the internal components of the indexing tool402, as discussed below. The indexing tool402may also optionally be accompanied by an upper drag block body406, positioned uphole of the main body404, and/or a lower drag block body408, positioned downhole of the main body404. Drag block bodies are generally known in the art and serve to act as anchors for the string. For this purpose, the drag block bodies are provided with drag block, such as shown at410and412. Slips, such as shown at414may also be provided with the drag block bodies.

In one aspect, the indexing tool may also optionally be associated with a packer such as shown at416. In one aspect, the packer416is axially located uphole of the indexing tool402and downhole of the shifting tool100.

The shifting tool is provided with an intermediary sub418connected to the downhole end of the shifting tool100, and more particularly to the bottom crossover sub120. The intermediary sub418is connected to the shifting tool100so as to avoid relative axial rotation therebetween.

As more clearly shown inFIG. 39, a mandrel420, which forms a component of the indexing tool402, is connected to the intermediary sub418and, as with the shifting tool100, in such a manner as to prevent relative axial rotation therebetween. In this regard, the mandrel420may be connected to the intermediary sub420by a locking nut or pin422. The mandrel comprises a generally elongate tubular body that extends through the length of the indexing tool402.

FIGS. 40 and 41illustrate the indexing tool402in cross-sectional views. As shown, the indexing tool comprises the mandrel420that is provided generally coaxially within the main body404. As noted above, the uphole end of the mandrel420is connected in a generally fixed manner to the shifting tool100. The downhole end of the mandrel is provided with a “J” barrel424. The mandrel420and J barrel are connected in a generally coaxial manner and also in such a manner as to prevent relative axial rotation therebetween. In one aspect, the downhole end of the mandrel420is provided with a threaded pin portion, which is adapted to be threadingly engaged within a correspondingly threaded box portion of the J barrel. This is further illustrated inFIG. 42, where the threaded box of the J barrel424is illustrated at426.

The J barrel comprises is provided with a series of slots, commonly referred to as “J” slots, on the outer surface thereof. The J slots are designed to cooperate with a lug ring428as shown in isolation inFIG. 43. The lug ring428is immovably secured to the housing404, such as by welding or other such means. The lug ring428comprises one or more internally extending lugs430. As will be explained, the number of lugs430corresponds to the number of J slots provided on the J barrel.

InFIG. 42, the J barrel424is illustrated in one aspect as having three longitudinally extended first slots432. The slots are generally equidistantly provided over the circumference of the J barrel424. Thus, in the aspect illustrated, each first slot432is separated by 120° from the adjacent first slot. As shown, the first slots432extend from the uphole end434of the J barrel and approach the downhole end436thereof. The downhole end436of the J barrel comprises a series of shorter second slots438extending towards the uphole end434of the J barrel and generally parallels to the first slots432, but only extending partially along the length of the J barrel, as illustrated inFIG. 42. The second slots438are also equidistantly provided over the circumference of the J barrel. The number of the second slots438corresponds to the number of first slots432. Thus, in the aspect shown, three second slots438are provide, which are also separated from each other by 120°. The downhole end436of the J barrel further comprises a number of indexing slots440. As shown, each indexing slot440is provided generally between each of the first and second slots. As a result, in the aspect shown inFIG. 42, six indexing slots440are provided.

As noted inFIG. 42, the first and second slots,432and438, are separated by first walls442having terminal ends444that extend in the direction of a respective indexing slot440. Similarly, the indexing slots440are separated by second walls446, each having terminal ends448that extend in the direction a respective first or second slot. As illustrated inFIG. 42, this arrangement of slots432,438, and440, and respective walls, forms a continuous travel path over the circumference of the J barrel proximal to the downhole end436thereof. This travel path is adapted to receive the lugs430of the lug ring. As also illustrated inFIG. 42, the terminal ends444and448of the walls are each provided with an angularly arranged end for guiding the lugs through the travel path. More specifically, as a given lug exits one of the first or second slots,432or438, it encounters the terminal end448of a wall extending between the indexing slots440. The angled terminal end448serves to circumferentially direct the lug in a predetermined direction, thereby forcing the lug430into a given indexing slot440. As the lug430is withdrawn from the indexing slot440it encounters the similarly angled terminal end444of the first wall442, which diverts the lug in the same circumferential direction and into the next first or second slot. Subsequently, when the lug is moved from that position it is sequentially diverted circumferentially into the neighbouring slots.

As mentioned above, the lug ring428is secured to the housing424and is immovable therewith. On the other hand, the mandrel and J barrel and provided in the indexing tool in an axially rotatable arrangement. Thus, as will be understood as the mandrel is axially moved with respect to the housing the arrangement of the slots and lugs mentioned above results in rotation of the mandrel with respect to the housing. Thus, when starting from the lugs in a given first slot432, as the mandrel is moved in the downhole direction, the lugs encounter the terminal ends448of the second walls446and are forced to enter adjacent indexing slots440caused by the rotation of the mandrel. Further axial movement of the mandrel towards the downhole direction is prevented once the lugs are lodged in the indexing slots440. At this point, the mandrel420is moved in the uphole direction, which forces rotation of the mandrel as the lugs encounter the ends444of the first walls442and causes the lugs to enter the shorter second slots438. Again, axial movement of the mandrel420is blocked as the lugs enter the ends of the second slots438. It will be understood that at this point, the mandrel420has undergone a 60° axial rotation. As the mandrel420is again moved in the downhole direction, the travel of the lugs430through the continuous passage of the J barrel causes the lugs to enter adjacent indexing slots440. Finally, axial movement of the mandrel420in the uphole direction causes rotation of the mandrel420and causes the lugs430to enter into adjacent first slots432. It will therefore be understood that movement of the lugs from one first slot to an adjacent first slot, as described above, results in a 120° axial rotation of the mandrel.

Referring back to the earlier description, it was noted that the mandrel420is secured to the shifting tool100in such a manner that relative axial rotation between the mandrel420and the shifting tool100was prevented. In addition, the shifting tool100was indicated as being connected to the remaining uphole portion of the work string by means of a swivel body400, thereby allowing the shifting tool100to axially rotate with respect to the work string. As can therefore be understood as the mandrel420is reciprocally moved in an axial direction with respect to the housing404of the indexing tool402, the resulting axial rotation of the mandrel420is imparted to the shifting tool. Thus, when a situation is encountered where the shifting tool is unable to sufficiently engage a sliding sleeve, the operation need only manipulate the work string in the axial direction (by extending and withdrawing the works string) with respect to the housing of the indexing tool to result in rotation of the shifting tool100. By rotating the shifting tool circumferentially by up to 120°, the operator is able to engage a new section of the sliding sleeve and seek to avoid the problem region of the tubing string.

As will be understood, the packer416, slips414, and drag blocks410and412, aid in securing the housing404in position both axially and rotationally, thereby further ensuring that the reciprocal movement of the mandrel420imparts rotation only to the mandrel and shifting tool100.

It should be noted that the indexing tool described herein offers a unique advantage when operating the aforementioned tools with a work string comprising coiled tubing, since such tubing is not rotatable when in use. In the result, the only manipulation possible with coiled tubing is in the axial direction. Thus, the indexing tool described herein allows axial manipulation of a coiled tubing work string to impart rotational movement to a tool provided thereon. In the above description, the tool being rotated is indicated as being position uphole of the indexing tool. However, it will be understood that such tool may instead be positioned downhole of the indexing tool. In such case, it will be understood that the slots described above would be located on the uphole end of the J barrel. While the indexing tool402has been described in relation to axial rotation of the shifting tool100, it will be appreciated that such tool can be used for manipulating any tool on a work string.

Although the above description includes reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art. Any examples provided herein are included solely for the purpose of illustration and are not intended to be limiting in any way. Any drawings provided herein are solely for the purpose of illustrating various aspects of the description and are not intended to be drawn to scale or to be limiting in any way. The scope of the claims appended hereto should not be limited by the preferred embodiments set forth in the above description but should be given the broadest interpretation consistent with the present specification as a whole. The disclosures of all prior art recited herein are incorporated herein by reference in their entirety.