GB2513152A

GB2513152A - Anchor ring assembly

Info

Publication number: GB2513152A
Application number: GB1306968.7A
Authority: GB
Inventors: Mike Allen; David Matthew Hare; Christopher George Barnes
Original assignee: Reactive Downhole Tools Ltd
Current assignee: Reactive Downhole Tools Ltd
Priority date: 2013-04-17
Filing date: 2013-04-17
Publication date: 2014-10-22
Also published as: WO2014170685A2; WO2014170685A3; US20160076324A1; NO2986813T3; EP2986813B1; CA2909526A1; EP2986813A2; GB201306968D0

Abstract

An anchor ring assembly (10) for anchoring to a mandrel (12) comprises an annular housing (14) which defines a through bore (15) to permit mounting on a mandrel (12). A plurality of slips (16) are circumferentially arranged within the through bore (15) of the housing (14), and a plurality of activator members (28) extend from an external surface of the housing (14) to engage the slips (16), wherein the activator members (28) are adjustable relative to the housing to extend the slips (16) radially inwardly to engage and grip a mandrel (12). This mechanism is particularly useful as an end ring or stop collar for attaching swellable or cup sealing elements to a tubular or mandrel and used as a well packer.

Description

ANCHOR RING ASSEMBLY

FIELD OF THE INVENTION

The present invention relates to an anchor ring assembly for anchoring to a mandrel, for example to provide end support to seal, such as a packer for providing a seal in a wellbore annulus.

BACKGROUND TO THE INVENTION

Many industries may require components to be located and secured to a mandrel, such as a tubular body. For example, in the oil and gas industry annular seals are frequently employed which are mounted on a mandrel and function to extend radially outwardly from the mandrel to engage a bore wall, thus sealing the annulus between the mandrel and bore wall. Such a seal is often referred to as a packer.

Known packers or seals in the oil and gas industry may be activated in a number of ways to be extended radially outwardly, for example by being axially compressed, by swelling, by inflation or the like.

In many seal designs the sealing component is located on a mandrel against metal end rings. Such end rings are located at one or both axial ends of a sealing body, and may be secured to the mandrel by welding, via set screws or the like.

The end rings may anchor a sealing component to the mandrel. Additionally, such end rings may also function to prevent unwanted axial deformation of the sealing component, for example due to extrusion when exposed to a pressure differential, which might otherwise compromise the integrity of any established seal. This may be of particular importance in swellable seal designs, wherein the end rings function to prevent or minimise axial swelling, such that the swelling of the seal may be restricted primarily to the radial direction.

Of critical importance in the design of end rings is their ability to provide a sufficient anchor to resist any displacing forces which might be experienced, and in some instances a poorly anchored end ring may result in failure of any associated seal.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided an anchor ring assembly for anchoring to a mandrel, comprising: an annular housing defining a through bore to permit mounting on a mandrel; a plurality of slips circumferentially arranged within the through bore of the housing; and a plurality of activator members extending from an external surface of the housing to engage the slips, wherein the activator members are adjustable relative to the housing to extend the slips radially inwardly to engage and grip a mandrel.

In use, the anchor ring assembly may be mounted on a mandrel and located in a desired position, with the activator members then adjusted relative to the housing to extend the slips radially inwardly to engage and grip the outer surface of the mandrel, thus anchoring or locking the anchor ring assembly to the mandrel.

The anchor ring assembly may be used in various applications. For example, the anchor ring assembly may be for use in defining a no-go profile on a mandrel.

The anchor ring assembly may define or function as an end ring for a seal element, such as an annular seal element, swellable seal element, axially compressible seal element, cup seal element and/or the like. The anchor ring assembly may be configured to resist axially applied forces, such as axial pressure forces established by exposure to a pressure differential across a seal element. Such resistance to axial forces may permit the anchor ring assembly to provide support to assist the seal element to resist extrusion.

The anchor ring assembly may be configured to provide support to a seal element. The anchor ring assembly may be configured to secure a seal element on or relative to a mandrel.

The anchor ring assembly may be suitable for use in securing to a mandrel in the form of a tubular, such as an oilfield tubular, for example a casing tubular, liner tubular, production tubular, tool sleeve or the like.

The activator members may comprise activator screws threadedly engaged with the housing to permit adjustment to extend the respective slips.

A single activator member may be provided for each slip. In other embodiments one slip may be associated with multiple activator members.

The activator members may be configured to engage respective rear faces of the slips. An activator member may be configured to abut a respective slip. In such an arrangement adjustment of an activator member relative to the housing may function to extend an associated slip. In some embodiments an activator member may be secured to a respective slip. Such an arrangement may permit the activator member to be adjusted relative to the housing to permit both extension and retraction of the associated slip.

An activator member may be configured to engage a respective slip generally centrally thereof. For example, an activator member may be configured to engage a respective slip at an axial and/or circumferential central region of said slip.

Engagement of an activator member generally centrally of a respective slip may permit a degree of self-adjustment of said slip, for example to self-align with an outer surface of a mandrel. In one embodiment engagement of an activator member generally centrally of an associated slip may permit said slip to pivot relative to the housing.

Such pivoting may be possible in multiple directions. Such an arrangement may provide a self aligning function of the slips.

One or more slips may define an engagement profile on a rear surface thereof and configured to be engaged by a respective activator member. For example, such an engagement profile may comprise a recess, dimple, blind hole, channel or the like.

One or more slips may comprise a gripping profile on inwardly facing surfaces thereof for use in gripping an outer surface of a mandrel. Such a gripping profile may assist to increase a connection force between the anchor ring assembly and a mandrel.

The gripping profile may be defined by any suitable structure, such as by individual teeth or ribs, by a surface roughness, by a knurled profile, by use of inserted material such as a carbine or the like.

One or more slips may comprise first and second sets of gripping teeth. Said sets of gripping teeth may be orientated in opposing directions. Such an arrangement may permit the first set of gripping teeth to preferentially resist forces applied in one direction, such as one axial direction, and the second set of gripping teeth to preferentially resist forces applied in an opposite direction, such as an opposite axial direction. The first set of gripping teeth may be located on one axial side of a slip, and the second set of gripping teeth may be located on an opposite axial side of the slip.

One or more slips may facilitate an increase in an engagement area between the anchor ring assembly and a mandrel, which may permit a more robust connection to be achieved. Further, the use of slips which are extended to engage the outer surface of the mandrel may eliminate or minimise the requirement to alter the form of the mandrel to accommodate an anchor ring assembly.

One or more slips may be profiled to correspond to a profile of a mandrel. For example, one or more slips may be generally curved to permit engagement with a cylindrical mandrel. One or more slips may be curved to define a circumferential segment.

At least two, and in some embodiments all slips may be arranged such that circumferential ends thereof may be positioned generally adjacent to each other. This arrangement may maximise the total circumferential slip surface area which may engage a mandrel, thus permitting a more robust connection to be achieved.

The anchor ring assembly may comprise a plurality of spacer ribs circumferentially distributed around the through bore of the housing, wherein adjacent slips are separated by a respective spacer rib. Each spacer rib may extend generally axially relative to the housing. Circumferential ends of the slips may be positioned adjacent respective spacer ribs.

One or more spacer ribs may be integrally formed with the housing.

One or more spacer ribs may be separately formed and secured to the housing, for example via screws or the like.

Adjacent spacer ribs may define a pocket therebetween for receiving a respective slip. Each spacer rib may define tapered side faces, wherein the circumferential faces of each slip may define corresponding tapered faces. Such an arrangement may facilitate radial extension and retraction of the slips, with minimal interference from the spacer ribs. Furthermore, such tapered faces of the slips and spacer ribs may permit each slip to be appropriately guided into the circumferential groove of the housing upon retraction of said slips.

At least two circumferentially adjacent spacer ribs may secure a slip positioned therebetween. At least two circumferentially adjacent spacer ribs may define a limit of radial movement, such as inward radial movement, of a slip positioned therebetween.

In one embodiment at least two circumferentially adjacent ribs may define a minimum circumferential separation distance which is smaller than a circumferential dimension of a slip positioned therebetween. At least two circumferentially adjacent ribs may define a minimum circumferential separation distance which is smaller than a maximum circumferential dimension of a slip positioned therebetween. In such an arrangement, once the slip is interposed between adjacent ribs, said ribs will prevent said slip from being fully radially removed from the anchor ring assembly.

At least two circumferentially adjacent ribs may collectively define a retaining profile configured to retain a slip therebetween.

The anchor ring assembly may comprise a retaining arrangement configured to retain one or more slips mounted within the housing. The retaining arrangement may be configured to retain all slips within the housing. The retaining arrangement may be configured to apply a retaining force to one or more slips to retain said slips within the housing. Extension of one or more slips radially inwardly may be achieved against this retaining force. The retaining arrangement may be configured to bias one or more slips towards a retracted configuration. In such an arrangement adjustment of one or more activator members in a direction to extend the associated one or more slips may act against the bias of the retaining arrangement. Further, in such an arrangement adjustment of one or more activator members in a direction to retract the associated one or more slips may permit the bias of the retaining arrangement to cause said slips to be retracted.

The retaining arrangement may be mounted radially inwardly of the slips.

In one embodiment one or more slips may define a groove formed in an inner surface thereof for accommodating a retaining arrangement. A plurality, for example all, slips may define a groove, wherein when the slips are mounted within the housing each individual groove is aligned to receive the retaining arrangement. Such a collective groove may be generally circumferential. In some embodiments such a collective groove may be helical.

A groove provided in one or more slips for accommodating a retaining arrangement may define a groove width which is larger than the corresponding width of the retaining arrangement. Such an arrangement may permit a degree of relative motion between the slip or slips and the retaining arrangement, for example to permit compliance of the slip or slips during clamping against a mandrel.

The retaining arrangement may be configured to be mounted axially centrally of the slips. Such an arrangement may permit the slips to be self-aligning, for example to accommodate the profile of a mandrel. Such an arrangement may permit each slip to pivot about the retaining arrangement, which may provide a self-alignment function.

The retaining arrangement may comprise a single retaining element.

The retaining arrangement may comprise a spring member or element.

The retaining arrangement may define a split ring spring element configured to provide an outwardly directed retaining force.

At least one slip may define or comprise first and second gripping profiles, wherein a retaining arrangement is located between said first and second profiles. In such an embodiment the retaining arrangement may not interfere with the gripping function of the slips.

The annular housing may define a circumferential groove formed in an inner surface thereof, wherein said groove is configured to accommodate one or more slips.

The circumferential groove may be circumferentially continuous. Alternatively, the circumferential groove may be circumferentially discontinuous. For example, multiple discrete grooves or recesses may be provided within the housing. Such discrete grooves or recesses may define a plurality of circumferentially arranged pockets each for receiving or accommodating one or more slips.

The circumferential groove of the housing may be profiled, wherein at least one slip defines a corresponding profile to permit appropriate fitting of the slips within the groove.

The circumferential groove of the housing may be defined between opposing axial faces. Opposing axial ends of at least one slip may be profiled to correspond with the axial faces of the housing groove.

At least one axial face of the groove may extend generally perpendicular relative to a central axis of the housing. Such an axial face may define an annular shoulder. Such an axial face may permit load transference between the housing and at least one slip.

At least one axial face of the groove may be tapered. That is, at least one axial face of the groove may be tapered or obliquely aligned relative to a central axis of the housing. At least one axial face of at least one slip may be tapered to correspond and engage the tapered axial face of the groove. In use, an axial load applied on the housing, for example from an external component, such as a seal element, may be transmitted to at least one slip via the respective tapered faces, thus applying an inward radial force on said at least one slip. Such an inward radial force may function to increase the gripping force of the slips against a mandrel. Accordingly, increasing axial load applied on the housing, for example from an external component, may result in the gripping force of the slips being increased. As such, the anchor ring assembly may automatically respond to changes in applied axial forces.

Opposing axial faces of the groove, and opposing axial faces of at least one slip may be tapered. Such an arrangement may permit an increase in gripping force to be achieved in the event of an axial load applied in opposite axial directions.

At least one axial end face of the housing may be configured to be engaged by an external component, such as a seal component or element. At least one axial end face of the housing may define a load surface, such as a load shoulder or the like.

Such a load surface may be configured for transmission of force from an external component or environment into the anchor ring assembly.

At least one axial end face of the housing may be tapered relative to a central axis of the housing. Such a tapered surface may facilitate or assist with insertion of the anchor ring assembly, for example when mounted on a mandrel, into a bore, such as a well bore.

At least one axial end face of the housing may be generally perpendicular to central axis of housing.

At least one axial end face of the housing may be configured to be sealingly engaged with an external component, such as a sealing element.

At least one axial end face of the housing may be configured to be bonded to an external component, such as a seal component or element.

At least one axial end face of the housing may be configured to define a profile configured to permit engagement with a corresponding profile on an external component, such as a sealing element.

At least one axial end face of the housing may comprise an axial extension configured to engage an external component, such as a sealing element, for example a cup seal element. The axial extension may increase a surface area of contact between an external component and the housing. The axial extension may be configured to at least partially define a sealed surface between the housing and an external component.

The axial extension may be configured to at least partially define a bonded surface between the housing and an external component.

The anchor ring assembly may comprise a sealing arrangement configured to provide a seal with a mandrel. The sealing arrangement may be configured to provide a seal between the housing and a mandrel. The seal arrangement may comprise a mechanical seal, such as an 0-ring seal or the like. An inner surface of the housing may define a circumferential groove configured to accommodate a seal, such as an o-ring seal. An inner surface of the housing may define multiple circumferential grooves configured to accommodate respective seals.

The sealing arrangement may be configured to provide a seal between the slips and a mandrel. The slips may define one or more grooves configured to collectively accommodate a seal, such as an 0-ring seal.

A retaining arrangement configured to retain the slips within the circumferential groove of the housing may also define a sealing arrangement configured to provide a seal against a mandrel.

The anchor ring assembly may comprise a sealing element extending from one axial end of the housing. The sealing element may be configured for use in providing a seal in an annulus defined between a mandrel and an outer bore wall, such as an open drilled bore wall, the wall of a casing, pipeline or the like. The anchor ring assembly, and in particular the annular housing may provide axial support to such a sealing element, for example to help resist extrusion of the sealing element when exposed to a pressure differential.

The sealing element may comprise an annular sealing element.

The sealing element may comprise a swellable material configured to swell upon exposure to an activator, such as oil and/or water. In such an arrangement the anchor ring assembly, and in particular the housing when anchored to a mandrel via the slips, may function to restrict swelling of the swellable material in an axial direction.

In this way, swelling may be achieved primarily in a radial direction to facilitate sealing between the mandrel and an outer bore wall.

The sealing element may comprise an axially compressible sealing element. In such an arrangement the anchor ring assembly, and in particular the housing when anchored to a mandrel via the slips, may define a reaction point against which such a compressible sealing element may be compressed.

The sealing element may comprise a cup seal sealing element. One axial end of the cup sealing element may be engaged with the housing, for example sealingly engaged, and an opposite axial end of the cup sealing element may be free from support, so as to permit the seal element to function as a cup seal.

The sealing element may be bonded directly to a mandrel.

The sealing element may comprise: a support sleeve; an outer sealing material mounted on an outer surface of the support sleeve; and an inner sealing material mounted on an inner surface of the support sleeve.

In such an arrangement the outer sealing material may be configured to establish a seal with a wall of a bore, and the inner sealing material may be configured to establish a seal against a mandrel.

The support sleeve may extend along the entire axial length of the sealing element. In some embodiments the support sleeve may extend along a partial axial length of the sealing element.

The support sleeve may be fixed to the anchor ring assembly, for example to the housing of the anchor ring assembly.

According to a second aspect of the present invention there is provided a method for anchoring to a mandrel, comprising: mounting an anchor ring assembly on a mandrel, wherein the anchor ring assembly comprises an annular housing and a plurality of slips circumferentially arranged within a through bore of the housing; adjusting a plurality of activator members which extend from an outer surface of the housing to engage the respective slips to extend the slips radially inwardly to engage and grip the mandrel.

The anchor ring assembly according to the first aspect may be utilised in the method according to the second aspect.

According to a third aspect of the present invention there is provided a sealing assembly for use in providing a seal in an annulus between a mandrel and a bore wall, comprising: an annular housing defining a through bore to permit mounting on a mandrel,; a plurality of slips circumferentially arranged within the through bore of the housing; a plurality of activator members extending from an external surface of the housing to engage the slips, wherein the activator members are adjustable relative to the housing to extend the slips radially inwardly to engage and grip a mandrel; and a sealing element extending from one axial end of the housing.

The sealing assembly may comprise two annular housings located at opposite ends of the sealing element, wherein each annular housing accommodates slips for anchoring to a mandrel. In such an arrangement the sealing element may be supported at opposing ends.

The sealing assembly may comprise a single housing, such that the sealing element is supported at a single end.

The sealing element may comprise any suitable type of sealing element, such as a swellable sealing element, compressible sealing element, a cup sealing element or the like.

The housing may comprise an axial extension extending from one axial end face thereof to permit engagement with the sealing element.

The sealing assembly may include an anchor ring assembly according to the first aspect.

According to a fourth aspect of the present invention there is provided a sealing assembly comprising: a mandrel; an annular sealing element bonded to the outer surface of the mandrel, wherein the sealing element comprises a swellable material configured to swell upon exposure to an activator.

The activator may comprise water, oil, gas or the like.

According to a fifth aspect of the present invention there is provided a sealing assembly comprising: a support member; an outer swellable sealing element mounted on an outer surface of the support member; and an inner swellable sealing element mounted on an inner surface of the support member, wherein the outer swellable sealing element is configured to swell to define a seal between the support member and a bore wall, and the inner swellable sealing element is configured to swell to define a seal between the support member and a mandrel.

The sealing assembly may be configured to be mounted on a mandrel, for example to be slipped on to one end of a mandrel.

The support member may comprise a metallic support member. The support member may be generally cylindrical. The support member may comprise one or more perforations through its wall structure. The inner and outer sealing elements may engage each other via these perforations. In one embodiment the inner and outer sealing elements may be integrated, for example continuous, via these perforations.

The sealing assembly may comprise one or more end rings. The support member may be secured or at least engage at least one end ring.

The outer sealing element may engage an axial end face or surface of an end ring.

The inner sealing element may engage an axial end face or surface of an end ring.

The inner sealing element may engage an inner circumferential face of an end ring. Such an arrangement may permit the inner sealing element to also establish a seal between an end ring and a mandrel.

An end ring may be configured to be secured relative to the support member via one or more screws, such as set screws, grub screws or the like.

An end ring may comprise an anchor ring assembly according to the first aspect.

According to a sixth aspect of the present invention there is provided a sealing assembly for use in providing a seal in an annulus between a mandrel and a bore wall, comprising: an annular housing defining a through bore to permit mounting on a mandrel, wherein the annular housing includes a sealing arrangement for providing a seal between the annular housing and a mandrel; a plurality of slips circumferentially arranged within the housing, wherein the slips are configured to be extended radially inwardly to engage and grip a mandrel; and a cup sealing element extending from one axial end of the housing.

One axial end of the housing may include an axial extension configured to engage the cup sealing element.

The cup sealing element may be bonded to one axial end of the housing.

The sealing arrangement provided between the housing and a mandrel may comprise one or more mechanical seals, such as 0-ring seals.

The sealing assembly may comprise an anchor ring assembly according to the first aspect.

Features defined in relation to one aspect may be provided in combination with any other aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of an anchor ring assembly according to an embodiment of the present invention; Figure 2 is a side view of the anchor ring assembly of Figure 1, shown mounted on a mandrel, wherein the mandrel is illustrated in broken outline; Figure 3 is a cross sectional view of the anchor ring assembly taken through line 3-3 of Figure 2, with the mandrel removed for clarity; Figure 4 is a cross sectional view of the anchor ring assembly taken through line 4-4 of Figure 2, with the mandrel removed for clarity; Figure 5 is a perspective view of a single slip which forms part of the anchor ring assembly; Figure 6 is a cross-section view of the anchor ring assembly taken through line 6-6 of Figure 2, with the mandrel removed for clarity; Figure 7 illustrates a sealing assembly according to an embodiment of the present invention, which incorporates a pair of anchor ring assemblies; Figure 8 illustrates a sealing assembly according to another embodiment of the present invention, which incorporates a pair of anchor ring assemblies; Figure 9 is a cross sectional view of a portion of an anchor ring assembly according to an alternative embodiment of the present invention; Figure 10 is a perspective view of an anchor ring assembly according to an alternative embodiment of the present invention; Figure 11 is a side view of the anchor ring assembly of Figure 10, shown mounted on a mandrel, wherein the mandrel is illustrated in broken outline; Figure 12 is a cross sectional view of the anchor ring assembly taken through line 12-12 of Figure 11, with the mandrel removed for clarity; Figure 13 is an enlarged view of a portion of the anchor ring assembly as shown in the section of Figure 12, with a slip removed; Figure 14 illustrates a sealing assembly according to an embodiment of the present invention, with an end ring removed for clarity; and Figure 15 illustrates a sealing assembly according to an alternative embodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

A perspective view of an anchor ring assembly, generally identified by reference numeral 10, is shown in Figure 1, and a side view of the same assembly 10 is illustrated in Figure 2. As will be described in detail below, the anchor ring assembly is for use in anchoring to a mandrel 12, which is illustrated in Figure 2 in broken outline. The mandrel 12 may comprise a tubular member, such as an oilfield tubular.

The anchor ring assembly 10 may have utility in multiple applications. In some of the examples below the assembly 10 is utilised to function as an end ring in a sealing assembly, such as a packer assembly.

The anchor ring assembly 10 includes an annular housing 14 which defines a throughbore 15 to permit the housing 14 to be mounted on the mandrel 12. The assembly 10 further comprises a plurality of slips 16 (five in the embodiment shown) which are circumferentially arranged within a circumferential groove 18 formed in an inner surface of the housing 14, wherein the slips 16 are each located between circumferentially arranged spacer ribs 20 which are secured to the housing via screws 22, as also illustrated in Figure 3 which is a cross-sectional view through line 3-3 of Figure 2. Each rib 20 includes tapered side faces 24, and the circumferential end faces 26 of each slip 16 correspond such that the slips 16 may be permitted to be displaced radially inwardly without interference from the ribs 20. Furthermore, the corresponding faces 24, 26 of the ribs 20 and slips 16 may function to align the slips 16 within the circumferential groove 18 of the housing 14 when moved towards a retracted position.

A plurality of activator members in the form of screws 28 extend from the outer surface of the housing 14 and engage the rear faces of the respective slips 16, as shown in Figure 4 which is a cross sectional view through line 4-4 of Figure 2.

Adjustment of the activator screws 28 relative to the housing 14 permits the slips 16 to be extended radially inwardly to grip the outer surface of the mandrel 12 and thus anchor the assembly 10 thereto.

A single activator screw 28 is provided for each slip 16, and each screw 28 engages the rear face of a slip 16 generally centrally thereof. This arrangement permits the slips 16 to pivot about the contact point with the screws 26 which assists with self-alignment of the slips 16 with the mandrel 12.

In the present embodiment one axial end face 30 of the housing 14 is generally perpendicular to a central axis of the housing 14. As best illustrated in Figure 2, such a perpendicular end face 30 defines an annular shoulder relative to the mandrel 12. This annular shoulder or face 30 may be used to support an adjacent external component, such as a sealing element for defining a seal between the mandrel 12 and a bore wall.

An opposite axial end face 32 of the housing 14 defines a tapered surface. This may facilitate insertion of the mandrel 12 and mounted anchor ring assembly 10 into a bore, for example to minimise snagging of the assembly 10 with any restrictions in such a bore.

An individual slip 16 is illustrated in Figure 5, reference to which is additionally made. Each slip 16 is generally arcuate or curved in form and includes first and second sets of gripping profiles in the form of sets of teeth 34, 36 which function to increase the anchoring force against the mandrel 12. In the embodiment shown, the first and second sets of gripping teeth 34, 36 are orientated in opposing directions, which permits the first set of gripping teeth 34 to preferentially resist forces applied in one axial direction, and the second set of gripping teeth 36 to preferentially resist forces applied in an opposite axial direction.

Each slip 16 includes a central groove 38 which are aligned when the slips 16 are mounted within the housing 14. The grooves 38 are configured to receive a split ring spring member 40, as illustrated in Figures 1 and 4, which functions to retain each slip 16 within the circumferential groove 18 of the housing 14. Further, the spring member 40 applies a biasing force against the slips 16 to bias said slips towards a retracted position, for example when the activator screws 28 are adjusted relative to the housing 14 to permit retraction of the slips 16. In some embodiments the grooves 38 each are wider than the spring member 40 in the axial direction. Such an arrangement may permit a degree of relative movement therebetween.

Reference is now additionally made to Figure 6 which is a cross sectional view of the assembly 10 taken through line 6-6 of Figure 2. As illustrated, the circumferential groove 18 formed in the housing includes opposing tapered side faces 42. Further, each slip 16 includes corresponding tapered side faces 44. In use, an axial load applied on the housing 14, for example from an external component, such as a seal element, may be transmitted to the slips 16 via the respective tapered faces 42, 44, thus applying an inward radial force on the slips 16. Such an inward radial force may function to increase the gripping force of the slips 16 against the mandrel 12.

Accordingly, increasing axial load applied on the housing 14, for example from an external component, may result in the gripping force of the slips 16 being increased.

As such, the anchor ring assembly 10 may automatically respond to changes in applied axial forces.

As noted above, the anchor ring assembly 10 may be used in multiple applications, including as an end ring within a sealing assembly, such as illustrated in Figure 7. In this exemplary embodiment a sealing assembly, generally identified by reference numeral 50, includes an annular sealing element 52 which is bonded directly to the mandrel 12, and a pair of anchor ring assemblies 10, as described above, are located and anchored to the mandrel 12 at opposing ends of the sealing element 52.

The sealing element 52 may be composed of or include a swellable material, such as a swellable rubber, which swells when contacted by a suitable activator, such as oil and/or water.

The anchor ring assemblies 10 may function to provide axial support to the sealing element 52, for example to assist the sealing element 52 to resist extrusion, to restrict any axial swelling and the like. Further, the anchor ring assemblies 10 may protect the sealing element 52 while the mandrel 12 is run into a bore.

In the present embodiment the sealing element 52 may first be bonded to the mandrel, and the anchor ring assemblies 10 then located in place. Alternatively, the anchor ring assemblies 10 may be located on the mandrel and secured in place, with the sealing element 52 then located and bonded to the mandrel 12.

An alternative embodiment of a sealing assembly, in this case generally identified by reference numeral 60, is illustrated in Figure 8. The sealing assembly 60 includes a sealing element 62 which is mounted about the mandrel 12. However, in this case the sealing element 62 is not bonded to the mandrel 12, but instead is simply slipped over the mandrel 62 and located in the desired position. A pair of anchor ring assemblies 10, as described above, are mounted on the mandrel 12 at opposing ends of the sealing element.

As in the embodiment shown in Figure 7, the sealing element 62 in Figure 8 may include a swellable material. In particular, the sealing element 62 is composed of a support sleeve 64, which may be of a metal construction, an outer swellable layer 66 mounted on an outer surface of the support sleeve 64, and an inner swellable layer 68 mounted on an inner surface of the support sleeve 64. In use, the outer layer 66 may swell to provide a seal between the support sleeve 64 and a bore wall, and the inner layer 66 may swell to provide a seal between the support sleeve 64 and the mandrel 12. In some embodiments the sleeve 64 may be perforated such that the outer and inner swellable layers 66, 68 may be integrated with each other through the perforations.

Reference is now made to Figure 9 which is a cross sectional view of a portion of an anchor ring assembly, generally identified by reference numeral 110, in accordance with an alternative embodiment of the present invention. Anchor ring assembly 110 is similar to that assembly 10 first shown in Figure 1 and as such like features share like reference numerals, incremented by 100. Accordingly, the assembly 110 includes a housing 114 and a plurality of slips 116 arranged within a circumferential groove 118 formed in the inner surface of the housing 114. As in the embodiment first shown in Figure 1, the slips 116 in the present embodiment may be extended by use of activator screws (not shown) to grip a mandrel (also not shown).

In the present embodiment the housing 114 defines a pair of circumferential grooves 70, 72 on either side of the slips 116 which are configured to receive respective 0-rings 74, 76. These 0-rings 74, 76 permit a seal to be achieved between the housing 114 and a mandrel.

One end of the housing 114 includes an axial extension 78 which in the present embodiment is for use in engaging an end of a sealing element 80, which is shown in broken outline. The sealing element 80 is bonded to the axial extension 78, thus achieving a seal therebetween.

In the present embodiment the sealing element 80 defines a cup sealing element, having a proximal end 82 secured to the axial extension 78, as described above, and having a distal end (not illustrated) being free from support, such that a pressure differential across the sealing element 80 may act to extend the distal end against a bore wall, to establish and/or increase a seal therebetween. In this respect, the 0-rings 74, 76 function to prevent leakage of fluid/pressure across the anchor ring assembly 110.

A perspective view of anchor ring assembly 210 in accordance with an alternative embodiment of the present invention is shown in Figure 1, and a side view of the same assembly 210 is illustrated in Figure 2, shown mounted on a mandrel 212 (shown in broken outline). Anchor ring assembly 210 is similar to assembly 10 first shown in Figure 1, and as such like components share like reference numerals, incremented by 200.

Accordingly, the anchor ring assembly 210 includes an annular housing 214 which defines a throughbore 215 to permit the housing 214 to be mounted on the mandrel 212. The assembly 210 further comprises a plurality of slips 216 (ten in this present embodiment) which are circumferentially arranged within a circumferential groove 218 formed in an inner surface of the housing 214. The slips 216 are located between circumferentially arranged spacer ribs 220 which are secured to the housing via screws 222. As will be described in more detail below, the ribs 220 function to hold or retain the slips 216 within the housing 214, while still permitting the slips to be moved radially. As such, additional retaining features, such as split rings, are not necessarily required in the present embodiment.

A plurality of activator members in the form of screws 228 extend from the outer surface of the housing 214 and engage the rear faces of the respective slips 216, as shown in Figure 12 which is a cross sectional view through line 12-12 of Figure 10.

Adjustment of the activator screws 228 relative to the housing 214 permits the slips 216 to be extended radially inwardly to grip the outer surface of the mandrel 212 and thus anchor the assembly 210 thereto.

In the present embodiment one axial end face 230 of the housing 214 is generally perpendicular to a central axis of the housing 214, and an opposite axial end face 232 of the housing 214 defines a tapered surface.

In a similar manner to the slips 16 of assembly 10, the slips 216 in the present embodiment define an arcuate inner surfaces which include a gripping profile in the form of teeth 35. However, in the present embodiment the teeth are arranged in a common direction.

As noted above, the ribs 220 function to retain the slips 216 within the housing.

In this respect, reference is now made to Figure 13, which is an enlarged view of a portion of the anchor ring assembly 210 as shown in the section of Figure 12, with a slip 216a removed from a pocket 90 defined between two circumferentially adjacent ribs 220a, 220b. The ribs 220a, 22b are formed and arranged within the housing 214 to define a radially inner circumferential separation distance 92 which is smaller than the radially outer circumferential length 94 of the slip 216a. Accordingly, once the slip 21 6a is mounted within the pocket 90, and the ribs 220a, 220b are securely fastened to the housing 214, the slip 21 Ga will not be permitted to be removed, yet will be permitted to move radially within the housing to selectively grip and release a mandrel 212.

Reference is now made to Figure 14 of the drawings in which there is shown a sealing assembly, generally identified by reference numeral 300, in accordance with an embodiment of the present invention. The assembly 300 is adapted to be slipped over a mandrel (not shown), and located in the desired position, thus providing a degree of freedom on where and when to apply the sealing assembly 300.

The assembly 300 includes a sealing component 302 which extends between opposing end rings 304, wherein one end ring is shown removed from the assembly 300 to reveal features of the sealing component 302. The end rings 304 may function to secure the entire assembly 300 to a mandrel.

The sealing component 302 includes a support sleeve 308 which may be of a metal construction and which extends between the end rings 304. An outer swellable seal layer 310 is mounted on an outer surface of the support sleeve 308, wherein the outer layer 310 is axially shorter than the support sleeve 308. An inner swellable seal layer 312 is mounted on an inner surface of the support sleeve 308, wherein the inner layer 312 is axially longer than the support sleeve 308. In use, the outer layer 310 may swell to provide a seal between the support sleeve 308 and a bore wall, and the inner layer 312 may swell to provide a seal between the support sleeve 308 and a mandrel, thus achieving a complete annular seal between the mandrel and bore wall.

The end rings 304 may be mounted relative to the sealing component 302 such that an end face 314 of the rings 304 abuts or engages the outer seal layer 310, whereas an inner surface of the ends rings 304 engages or abuts the support sleeve 308 and optionally the inner seal layer 312. In this respect, swelling of the inner layer 312 may function to establish a seal against the end rings 304, for example between the end rings 304 and a mandrel.

In an alternative embodiment, which is not illustrated, the support sleeve 308 and outer and inner seal layers 310, 312 may be of equal axial lengths. In a further alternative embodiment, the support sleeve 308 may be axially shorter then the inner and outer seal layers 310, 312. Further, the support sleeve 308 may be perforated, and the inner and outer seal layers 310, 312 may engage, for example be integrally formed, through the perforations.

Reference is now made to Figure 15 which illustrates a sealing assembly, generally identified by reference numeral 320, in accordance with an alternative embodiment of the present invention, wherein the sealing assembly 320 is shown mounted on a mandrel 322, such as an oilfield tubular. In certain embodiments the mandrel 322 may form part of the sealing assembly 320. The mandrel 322 may be provided in the form of a pup joint. The mandrel 322 may include threaded connectors 328, 329 at opposing ends thereof. Connector 328 may be a pin type threaded connector, whereas connector 329 may be a box type threaded connector.

The sealing assembly 320 includes a swellable seal element 324 which is directly bonded to the outer surface of the mandrel 322. Such bonding may be achieved by use of an adhesive. Such bonding may be achieved by mounting the swellable material of the seal element 324 on the mandrel, and then vulcanising the material to cause the element 324 to become bonded to the mandrel 322.

The sealing assembly 320 further comprises a pair of end rings 326 mounted at opposite ends of the sealing element 324, and may be used to protect and axially support the seal element 324.

It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the invention. For example, the anchor ring assemblies may be for use in other applications beyond providing support to a sealing element or component, such as in establishing a no-go on a mandrel. Further, in some embodiments one, some or all of the ribs (such as ribs 22 or ribs 220) may be integrally formed with the housing.

Claims

CLAIMS: 1. An anchor ring assembly for anchoring to a mandrel, comprising: an annular housing defining a through bore to permit mounting on a mandrel; a plurality of slips circumferentially arranged within the through bore of the housing; and a plurality of activator members extending from an external surface of the housing to engage the slips, wherein the activator members are adjustable relative to the housing to extend the slips radially inwardly to engage and grip a mandrel.
2. The anchor ring assembly according to claim 1, wherein the activator members comprise activator screws threadedly engaged with the housing to permit adjustment to extend the respective slips.
3. The anchor ring assembly according to claim 1 or 2, wherein a single activator member is provided for each slip.
4. The anchor ring assembly according to claim 1, 2 or 3, wherein the activator member engage respective rear faces of the slips.
5. The anchor ring assembly according to any preceding claim, wherein an activator member is configured to engage a respective slip generally centrally thereof.
6. The anchor ting assembly according to any preceding claim, wherein at least one slip defines an engagement profile on a rear surface thereof to be engaged by a respective activator member.
7. The anchor ring assembly according to any preceding claim, wherein at least one slip comprises a gripping profile on inwardly facing surface thereof for use in gripping an outer surface of a mandrel.
8. The anchor ring assembly according to any preceding claim, wherein at least one slip comprises gripping teeth.
9. The anchor ring assembly according to any preceding claim, wherein at least one slip comprises first and second sets of gripping teeth.
10. The anchor ring assembly according to claim 9, wherein the first and second sets of gripping teeth are orientated in opposing directions.
11. The anchor ring assembly according to any preceding claim, wherein at least one slip defines a curved profile.
12. The anchor ring assembly according to any preceding claim, comprising a plurality of spacer ribs circumferentially distributed around the through bore of the housing, wherein adjacent slips are separated by a respective spacer rib.
13. The anchor ring assembly according to claim 12, wherein each spacer rib extends generally axially relative to the housing.
14. The anchor ring assembly according to claim 12 or 13, wherein adjacent spacer ribs define a pocket therebetween for receiving a respective slip.
15. The anchor ring assembly according to claim 12, 13 or 14, wherein each spacer rib defines tapered side faces, wherein the circumferential faces of each slip define corresponding tapered faces.
16. The anchor ring assembly according to any one of claims 1210 15, wherein at least two circumferentially adjacent spacer ribs retain a slip positioned therebetween within the assembly.
17. The anchor ring assembly according to any one of claims 1210 16, wherein at least two circumferentially adjacent spacer ribs define a limit of radial movement of a slip positioned therebetween.
18. The anchor ring assembly according to any one of claims 1210 17, wherein at least two circumferentially adjacent ribs define a minimum circumferential separation distance which is smaller than a circumferential dimension of a slip positioned therebetween.
19. The anchor ring assembly according to any one of claims 1210 18, wherein at least two circumferentially adjacent ribs define a minimum circumferential separation distance which is smaller than a maximum circumferential dimension of a slip positioned therebetween.
20. The anchor ring assembly according to any one of claims 1210 19, wherein at least two circumferentially adjacent ribs collectively define a retaining profile configured to retain a slip therebetween.
21. The anchor ring assembly according to any preceding claim, comprising a retaining arrangement configured to retain one or more slips mounted within the housing.
22. The anchor ring assembly according to claim 21, wherein the retaining arrangement is configured to apply a retaining force to one or more slips to retain said slips within the housing.
23. The anchor ring assembly according to claim 21 or 22, wherein the retaining arrangement biases one or more slips towards a retracted configuration.
24. The anchor ring assembly according to claim 21, 22 or 23, wherein the retaining arrangement is mounted radially inwardly of the slips.
25. The anchor ring assembly according to any one of claims 21 to 24, wherein one or more slips define a groove formed in an inner surface thereof for accommodating a retaining arrangement.
26. The anchor ring assembly according to any one of claims 21 to 25, wherein each slip defines a groove, wherein when the slips are mounted within the housing each individual groove is aligned to receive the retaining arrangement.
27. The anchor ring assembly according to any one of claims 21 to 26, wherein the retaining arrangement is mounted axially centrally of the slips.
28. The anchor ring assembly according to any one of claims 21 to 27, wherein the retaining arrangement comprises a spring member or element, such as a split ring spring element.
29. The anchor ring assembly according to any one of claims 21 to 28, wherein at least one slip comprises first and second axially separated gripping profiles, wherein a retaining arrangement is located between said first and second profiles.
30. The anchor ring assembly according to any preceding claim, wherein the annular housing defines a circumferential groove formed in an inner surface thereof, wherein said groove is configured to accommodate one or more slips.
31. The anchor ring assembly according to claim 30, wherein the circumferential groove is profiled, wherein at least one slip defines a corresponding profile to permit appropriate fitting of the slips within the groove.
32. The anchor ring assembly according to claim 30 or 31, wherein at least one axial face of the groove is tapered, and at least one axial face of at least one slip is tapered to correspond and engage the tapered axial face of the groove.
33. The anchor ring assembly according to claim 30, 31 or 32, wherein opposing axial faces of the groove, and opposing axial faces of at least one slip are tapered.
34. The anchor ring assembly according to any preceding claim, wherein at least one axial end face of the housing defines a load surface.
35. The anchor ring assembly according to any preceding claim, wherein at least one axial end face of the housing is tapered relative to a central axis of the housing.
36. The anchor ring assembly according to any preceding claim, wherein at least one axial end face of the housing comprises an axial extension configured to engage an external component, such as a sealing element.
37. The anchor ring assembly according to any preceding claim, comprising a sealing arrangement configured to provide a seal with a mandrel.
38. The anchor ring assembly according to any preceding claim, comprising a sealing element extending from one axial end of the housing.
39. A method for anchoring to a mandrel, comprising: mounting an anchor ring assembly on a mandrel, wherein the anchor ring assembly comprises an annular housing and a plurality of slips circumferentially arranged within a through bore of the housing; adjusting a plurality of activator members which extend from an outer surface of the housing to engage the respective slips to extend the slips radially inwardly to engage and grip the mandrel.
40. A sealing assembly for use in providing a seal in an annulus between a mandrel and a bore wall, comprising: an annular housing defining a through bore to permit mounting on a mandrel,; a plurality of slips circumferentially arranged within the through bore of the housing; a plurality of activator members extending from an external surface of the housing to engage the slips, wherein the activator members are adjustable relative to the housing to extend the slips radially inwardly to engage and grip a mandrel; and a sealing element extending from one axial end of the housing.
41. The sealing assembly according to claim 40, comprising two annular housings located at opposite ends of the sealing element, wherein each annular housing accommodates slips for anchoring to a mandrel.
42. A sealing assembly comprising: a mandrel; an annular sealing element bonded to the outer surface of the mandrel, wherein the sealing element comprises a swellable material configured to swell upon exposure to an activator.
43. A sealing assembly comprising: a support member; an outer swellable sealing element mounted on an outer surface of the support member; and an inner swellable sealing element mounted on an inner surface of the support member, wherein the outer swellable sealing element is configured to swell to define a seal between the support member and a bore wall, and the inner swellable sealing element is configured to swell to define a seal between the support member and a mandrel.
44. The sealing assembly according to claim 43, configured to be mounted on a mandrel.
45. The sealing assembly according to claim 43 or 44, wherein the support member comprise a metallic support member.
46. The sealing assembly according to claim 43, 44 or 45, wherein the support member is generally cylindrical.
47. The sealing assembly according to any one of claims 43 to 46, wherein the support member comprises one or more perforations through its wall structure.
46. The sealing assembly according to claim 47, wherein the inner and outer sealing elements engage, for example by being integrally formed, via the perforations.
49. The sealing assembly according to any one of claims 43 to 47, comprising one or more end rings.
50. The sealing assembly according to claim 49, wherein the support member engages at least one end ring.
51. The sealing assembly according to claim 49 or 50, wherein the outer sealing element engages an axial end face or surface of an end ring.
52. The sealing assembly according to claim 49, 50 or 51, wherein the inner sealing element engages an axial end face or surface of an end ring.
53. The sealing assembly according to any one of claims 49 to 52, wherein the inner sealing element engages an inner circumferential face of an end ring.
54. The sealing assembly according to any one of claims 49 to 53, wherein an end ring is secured relative to the support member via one or more screws.
55. A sealing assembly for use in providing a seal in an annulus between a mandrel and a bore wall, comprising: an annular housing defining a through bore to permit mounting on a mandrel, wherein the annular housing includes a sealing arrangement for providing a seal between the annular housing and a mandrel; a plurality of slips circumferentially arranged within the housing, wherein the slips are configured to be extended radially inwardly to engage and grip a mandrel; and a cup sealing element extending from one axial end of the housing.
56. The sealing assembly according to claim 55, wherein one axial end of the housing includes an axial extension configured to engage the cup sealing element.
57. The sealing assembly according to claim 55 or 56, wherein the cup sealing element is bonded to one axial end of the housing.