NL2007812C2

NL2007812C2 - Seal sleeve and assembly including such a seal sleeve.

Info

Publication number: NL2007812C2
Application number: NL2007812A
Authority: NL
Inventors: Roger Wilfred Hibberd
Original assignee: Ruma Products Holding B V
Priority date: 2011-11-18
Filing date: 2011-11-18
Publication date: 2013-05-23

Description

Title: Seal sleeve and assembly including such a seal sleeve.

Technical Field

The invention relates to a seal sleeve having a seal sleeve wall that includes swellable polymer material, to an assembly including such a seal sleeve and to a method for applying a seal sleeve between an inner element 5 and an outer element.

Background A swelling seal sleeve is known from e.g. W003/008756, W006/003113 and US2007/0056735. In all these publications the seal sleeves 10 disclosed therein are annular objects with a radial wall thickness in a non-swollen state and an increased radial wall thickness in a swollen state. In general, these swelling seal sleeves may be mounted on an inner element having an outer surface that has to be introduced into an outer element having an inner surface. The inner element may, for example, be production tubing 15 that has to be introduced into a bore well hole. In that example, the bore well hole or the casing thereof is the outer element.

A problem of the prior art swelling seal sleeves is the introduction of the inner element with the seal sleeve into an outer element having a hole with a inner surface with cross sectional dimensions that are only slightly 20 larger than the cross sectional dimensions of the seal sleeve. The introduction may, in particular, be problematic when distance along which the inner element with the seal sleeve has to be introduced into the outer element is large and/or when the hole extends along a torturous path.

25 Summary of the Invention

The invention is directed to a seal sleeve that alleviates the problems of the prior art.

More particularly, the invention is directed to a seal sleeve that can be more easily introduced in an outer element having an inner surface with 2 cross sectional dimensions that are only slightly larger than the cross sectional dimensions of the seal sleeve.

To that end the invention provides a seal sleeve including: • a seal sleeve wall comprising a swellable polymer material having 5 elastomeric properties so that the seal sleeve has non-swollen state and an expanded state, the seal sleeve wall having a closed circumference that extends around a central longitudinal axis and that has a certain length in the direction of the central axis; • the seal sleeve wall having a non-swollen thickness that is 10 defined by the distance of an inner surface and an outer surface of the seal sleeve wall in the non-swollen state and having an expanded thickness that is defined by the distance of an inner surface and an outer surface of the seal sleeve wall in the expanded state; and 15 • two free end surfaces; the seal sleeve being characterized in that the at least one of the end surfaces extends in a plane that includes a sharp angle with the longitudinal axis.

Such a seal sleeve may be applied for use in an assembly that 20 includes an inner element having an outer surface and an outer element with a hole having an inner surface. The inner element being receivable within the outer element so that a circumferential space is present that extends in the longitudinal direction and that has a radial width defined by the distance between the outer surface of the inner element and the inner surface of the 25 outer element. The seal sleeve is configured to close off the circumferential space in the expanded state thereof. In the non-swollen state the seal sleeve has a radial width that is less than the radial width of the circumferential space. The end surface that extends in a plane that includes a sharp angle with the longitudinal axis is more easily introduced into the hole in the outer 30 element. In the prior art seal sleeves the free ends of the seal sleeve wall each 3 extend in a plane associated with that free end that extends perpendicular to the longitudinal axis of the seal sleeve. When an irregularity is present in the inner wall of the outer element that bounds the hole, the free end of the prior art sleeves may easily get obstructed or stuck thus preventing further 5 introduction of the seal sleeve into the hole of the outer element. With the seal sleeve according to the invention, in having a free end that extends in a plane that includes a sharp angle with the longitudinal axis of the seal sleeve, the occurrence that an irregularity on the inner wall of the outer element leads to a obstruction or blocking of the inward movement of the inner element with 10 the seal sleeve is reduced considerably. It should be noted that the term sleeve in this context does not limit the scope to seals that may be disassembled from in inner element and thus be made slideable relative to the inner element. Additionally, seal sleeves that are permanently connected, bonded to or even integrally formed on inner element are contemplated.

15 Preferably, the sharp angle is in the range of 15°-50°. With a sharp angle in that range, the occurrence of obstruction or blocking during the introduction is minimized and the strength of the distal end point defined by the slanted free end of the seal sleeve is still sufficient.

In an embodiment a first one of the free end surfaces may extend in 20 a first plane that includes a first sharp angle with the longitudinal axis and wherein a second one of the free end surfaces may extend in a second plane that includes a second sharp angle with the longitudinal axis.

This embodiment has the advantage that it does not matter in which way the seal sleeve is mounted on the inner end. The first one of the free end 25 may be directed upstream or, alternatively downstream when viewed in the direction of introduction. In either case, a slanted free end is available at the upstream end of the seal sleeve, thus providing an improved introduction of the seal sleeve in the hole of the outer element.

In an embodiment the first and the second sharp angle may be the 30 same so that the first and the second plane are parallel.

4

In order to further improve the strength of the structure of the seal sleeve, in an embodiment, the seal sleeve may include a cylindrical core having a core wall that is stiff. The core may be a metal core or a rubber or plastic core with a high rigidity.

5 Such a core wall provides mechanical strength, stiffness to the seal sleeve and makes an easy and simple locking or mounting on an inner element possible. Additionally, the occurrence of extrusion of the seal sleeve may be reduced by virtue of the presence of the core.

In an embodiment, the core has two core end surfaces that are 10 defined by the core wall and that are each associated with an associated end surface of the seal sleeve wall, wherein each core end surface extends in a plane that is parallel to the plane in which the associated end surface of the seal sleeve wall extends.

By virtue of the fact that the end surfaces of the core extend parallel 15 to the free ends of the seal sleeve wall, the strength of the free ends of the seal sleeve wall is substantially constant over the entire circumference of the seal sleeve wall.

In an embodiment of the seal sleeve with a cylindrical core, the seal sleeve may have a seal sleeve wall that comprises a part also extends at least 20 partly at an inner surface of the cylindrical core. Such a construction may be advantageous for mounting the seal sleeve on an inner element, such as for example a metal pipe or tube. In the non-swollen state, the seal sleeve may be bonded to or slid over the metal pipe or tube and be fixed by one or more fixation methods including but not limited to screw or other fixation means 25 such as chemical or mechanical bonding or a mechanical locking system. When the swellable material is brought into the expanded state, a hermetically closed seal between the cylindrical core and the inner element is automatically obtained due to the expansion of the seal sleeve wall part that extends at the inner surface of the cylindrical core.

5

In an embodiment, the seal sleeve may include threaded holes in which bolts may be screwed to provide a connection between the inner element and the seal sleeve.

In an embodiment, the threaded holes may extend along a screw 5 axis that includes a sharp angle with the longitudinal axis of the seal sleeve. By virtue of the sharp angle between the screw and the outer wall of the inner element that is thus provided, a improved resistance against a relative sliding movement between the seal sleeve and the inner element may be provided.

The invention also provides an assembly of a seal sleeve according to 10 the invention and an inner element having an outer surface and an outer element having an inner surface, wherein the inner element is receivable within the outer element so that a circumferential space is present that extends in a longitudinal direction D and that has a radial width W defined by the distance between the outer surface of the inner element and the inner 15 surface of the outer element.

In an embodiment, the inner element may be a casing and the outer element may be a well bore hole wall.

In yet another embodiment, the inner element may be a production tubular and the outer element may be a casing of casing string in a well bore 20 hole.

The invention also provides a method for applying a seal sleeve between an inner element and an outer element. The method includes: • providing an outer element having inner surface; • providing an inner element having an outer surface, the dimension 25 of the inner element relative to the outer element being such that the inner element is receivable in the outer element; • providing a seal sleeve according to the invention; • applying the seal sleeve over the inner element; • fixing the seal sleeve at a longitudinal position on the inner element; 30 • introducing the inner element into the outer element; and 6 providing a liquid that induces the swelling of the swellable polymer material of the seal sleeve wall.

The invention will be further elucidated with reference to two 5 examples of embodiment that are shown in the drawings.

Brief Description of the Drawings

Fig. 1 shows an elevation view of an example of a first embodiment;

Fig. 2 shows a cross sectional view over line II-II of Fig. 1; 10 Fig. 3 shows a cross sectional view over line III-III of Fig. 1;

Fig. 4 shows an elevation view of an example of a second embodiment;

Fig. 5 shows a cross sectional view over line V-V of Fig. 4;

Fig. 6 shows a cross sectional view over line VI-VI of Fig. 4; and 15 Fig. 7 shows a cross sectional view of an assembly of an inner element, an outer element and the example of the embodiment of Fig. 1.

Detailed Descrintion

Figs. 1-3 show an example of a first embodiment of a seal sleeve 10. 20 Fig. 4-6 show an example of a second embodiment of a seal sleeve 10.

In general the disclosed seal sleeve 10 includes a seal sleeve wall 14 comprising a swellable polymer material having elastomeric properties so that the seal sleeve has non-swollen state and an expanded state. The seal sleeve wall 14 has a closed circumference that extends around a central longitudinal 25 axis A and that has a certain length in the direction of the central axis A. The seal sleeve wall 14 has a non-swollen thickness that is defined by the distance of an inner surface and an outer surface of the seal sleeve wall 14 in the non-swollen state and has an expanded thickness that is defined by the distance of an inner surface and an outer surface of the seal sleeve wall 14 in the 30 expanded state. The seal sleeve 10 has two free end surfaces that are defined 7 by the seal sleeve wall 14. The seal sleeve 10 is characterized in that the at least one of the end surfaces 14a, 14b extends in a plane PI, P2 that includes a sharp angle a with the longitudinal axis A. By virtue of this sharp angle a, introduction in a narrow hole of an outer element is easier and the chance that 5 the seal sleeve 10 with that is mounted on an inner element 100 gets stuck in the hole in the outer element 110 is minimized.

This effect is further optimized when the sharp angle a is in the range of 15°-50°.

In an embodiment, of which the figures show two examples, a first 10 one 14a of the free end surfaces 14a, 14b extends in a first plane PI that includes a first sharp angle a with the longitudinal axis A and a second one 14b of the free end surfaces 14a, 14b extends in a second plane P2 that includes a second sharp angle a’ with the longitudinal axis A. By virtue of the fact that both free end surfaces 14a, 14b are slanted, the manner in which the 15 seal sleeve 10 is mounted on the inner element 100 does not effect the ease of introduction of the inner element 100 into the hole of the outer element 110. To further optimize this effect, the first and the second sharp angle a, a’ may in an embodiment be the same so that the first and the second plane PI, P2 are parallel.

20 In an embodiment, of which examples are shown in the figures, the seal sleeve 10 may comprise a cylindrical core 12 that is stiff. In the examples that are shown in the figures, the cylindrical core 12 is provided at an inner side of the seal sleeve wall 14.

In an embodiment, of which the figures show two examples, the core 25 12 has two core end surfaces that are defined by the core wall and that are each associated with an associated free end surfaces 14a, 14b of the seal sleeve wall 14. Each core end surface may extend in a plane that is parallel to the plane PI, P2 in which the associated free end surface 14a, 14b of the seal sleeve wall 14 extends. Thus, a substantially uniform strength and stiffness of 8 the free ends of the seal sleeve 10 along the circumference of the seal sleeve 10 is obtained.

In an embodiment of a seal sleeve 10 with a cylindrical core 12, a part 14c of the seal sleeve wall 14 may also extend at least partly at an inner 5 surface of the cylindrical core 12. In such an embodiment, the cylindrical core 12 may be completely embedded in the seal sleeve wall 14 of swellable polymer material. Such an embodiment has the advantage of structural strength in combination with an easy mounting of the seal sleeve 10 on an inner element 100. The seal sleeve 10 may be shifted over the inner element 100 and may be 10 temporarily fixed by fixing means such as a fixing screw, a wedge or glue.

After swelling, the part of the seal sleeve wall 14 that is on the inside of the cylindrical core 18 expands against the inner element 100 and thus provides an excellent seal on that side as well.

In an embodiment, the seal sleeve may be provided with threaded 15 holes 18 in which bolts may be screwed to provide a connection between an inner element 100 and the seal sleeve 10. These holes 18 may extend along a screw axis that is perpendicular to the longitudinal axis as shown in the example of figures 1-3.

Alternatively, the threaded holes 18 may extend along a screw axis 20 A2 that includes a sharp angle |3 with the longitudinal axis A of the seal sleeve wall 14 as shown in the example of figures 4-6. Such an angled screw hole 18 has the advantage that an improved grip between the bolt that is screwed into the screw hole 18 and the inner element 100 may be obtained.

The example of the embodiment shown in Figs. 1-3 differs from the 25 example of the embodiment shown in Figs. 4-6 in that the example of Figs. 1-3 additionally includes a central cylindrical part 16 of non-swelling polymer material having an outer diameter D1 that is slightly larger than the outer diameter D2 of the swelling seal sleeve wall 12. This provides an additional advantage with respect to the of introduction of the seal sleeve 10 in a hole of 30 an outer element 110. By virtue of the larger diameter of the non-swelling part 9 16, it will be especially this part 16 of the seal sleeve that collides with the inner wall of the outer element 110 during introduction. This reduces the chance of damaging the seal sleeve wall 12 of the seal sleeve 10. In the illustrated example the non-swelling part 16 is a central part. It is also feasible 5 that the seal sleeve 10 includes two non-swelling parts 16 at the free ends of the seal sleeve 10 and that the swelling seal wall 12 is a central part. To further optimize the ease of introduction of a seal sleeve 10 with a nonswelling part 16, it is advantageous when the free ends 16a, 16b of the nonswelling part 16 or parts 16 are slanted as well, i.e. extend in a plane that 10 includes a sharp angle with the longitudinal axis Al. In an embodiment, this sharp angle is also typically in the range of 15°-50°.

Fig. 7 shows an example of an assembly of a seal sleeve 10, an inner element 100 having an outer surface and an outer element 110 having an inner surface. The inner element 100 is receivable within a hole in the outer 15 element 110 so that a circumferential space 120 is present that extends in a longitudinal direction and that has a radial width defined by the distance between the outer surface of the inner element 100 and the inner surface of the outer element 110. When the seal sleeve wall 14 is expanded circumferential space 120 is blocked by the expanded seal sleeve wall 14 so that a seal is 20 obtained.

In an embodiment of the assembly, the inner element 100 may be a production tubular and the outer element 110 may be a casing in a well bore hole. The casing 110 extends in a bore hole in an earth layer.

In an another embodiment of the assembly, the inner element 100 25 may a casing of a casing string and the outer element 110 may be a well bore hole wall.

In yet another embodiment, the outer element 110 may be a housing of an apparatus and the inner element 100 may be a shaft that is mounted in the housing.

10

Suitable elastomers are rubber materials which, apart from swelling in watery fluids alternatively or additionaly may swell in crude oil present in petroleum wells. Alternatively or additionally rubber materials may be used that swell in contact with certain gases. Watery fluids may be neutral, alkaline 5 or acid fluids. Examples of suitable rubber materials are ethylene propylene rubber (EPM and EPDM); ethylene- propylene-diene terpolymer rubber (EPT); butyl rubber (HR); brominated butyl rubber (BUR); chlorinated butyl rubber (CIIR); chlorinated polyethylene (CM/CPE); neoprene rubber (CR); epichlorohydrin ethylene oxide copolymer (CO, ECO); styrene butadiene 10 copolymer rubber (SBR); sulphonated polyethylene (CSM); ethylene acrylate rubber (EAM/AEM); silicone rubbers (VMQ); and fluor silicone rubber (FVMQ).

Also suitable are rubber materials which do not swell in crude oil, such as butadiene acrylonitrile copolymer (nitrile rubber, NBR); hydrogenated NBR (HNBR, HNS), such as ZETPOL™, TORNAC™, TERBAN™; NBR with 15 reactive groups (X-NBR); perfluoro rubbers (FFKM) such as KALREZ™, CHEMRAZ™; fluoro rubbers (FKM), such as VITON™, FLUOREL™; and tetrafluorethylene/propylene (TFE/P), such as AFLAS™.

Most of these elastomers can be crosslinked by more than one crosslinking agent (e.g. either sulphur crosslinked or peroxide crosslinked).

20 Apart from the thermoset (non swelling and oil swelling) elastomer matrix materials quoted above, also blends of elastomers can be applied (so called “elastomeric alloys”). Although an almost inexhaustible combination of thermoplastic and thermoset elastomers are feasible, the most preferred are the EPDM/polypropylene blends such as SARLINK™, Levaflex™, 25 Santoprene™, NBR-polypropylene blends such as GEOLAST™, NBR/polyvinylchloride blends and NR/polypropylene blends. All of these have a tendency to swell in petroleum crudes, especially at the targeted downhole well temperatures.

In an application of the seal sleeve 10, the following method may be 30 used: 11 • providing an outer element 110 having inner surface; • providing an inner element 100 having an outer surface, the dimension of the inner element 100 relative to the outer element 110 being such that the inner element 100 is receivable in the outer 5 element 110; • providing a seal sleeve 10 according to any one of claims 1-9; • applying the seal sleeve 10 over the inner element 100; • fixing the seal sleeve 10 at a longitudinal position on the inner element 100; 10 • introducing the inner element 100 into the outer element 110; • providing a liquid that induces the swelling of the swellable polymer material of the seal sleeve wall 12.

With this method the seal sleeve 10 may be applied at a desired position and an adequate sealing may be obtained both at the outer 15 circumference of the seal sleeve 10 and the inner circumference of the seal sleeve 10. When the seal sleeve 10 is provided with a cylindrical core 18 that is rigid, the sealing at the inside of the seal sleeve 10 may be further promoted when a part of seal sleeve wall 14 of swellable polymer material also extends at least partly along an inner surface of the cylindrical core 12.

20 Although illustrative embodiments of the present invention have been described above, in part with reference to the accompanying drawings, it is to be understood that the invention is not limited to these embodiments. Variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the 25 drawings, the disclosure, and the appended claims. Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an 30 embodiment" in various places throughout this specification are not 12 necessarily all referring to the same embodiment. Furthermore, it is noted that particular features, structures, or characteristics of one or more embodiments may be combined in any suitable manner to form new, not explicitly described embodiments.

Claims

A sealing sleeve (10) comprising: • a sealing sleeve wall (14) provided with swellable polymeric material with elastomeric properties such that the sealing sleeve has a non-swollen state and an expanded state, wherein the sealing sleeve wall (14) has a closed periphery extends around a central longitudinal axis (A) and a certain length in the direction of the central axis (A); Wherein the sealing sleeve wall (14) has a non-swollen thickness which is determined by the distance between an inner surface and an outer surface of the sealing sleeve wall (14) in the non-swollen state and has an expanded thickness determined by the distance between a inner surface and outer surface of the sealing cuff wall (14) in the expanded state; and • two free end surfaces (14a, 14b); characterized in that at least one of the end surfaces (14a, 14b) extends in a plane (P1, P2) that includes an acute angle (a) with the longitudinal axis (A). 20

The sealing sleeve according to claim 1, wherein the sharp angle (a) is in the range of 15-50 degrees.

3. The sealing sleeve according to claim 1 or 2, wherein a first (14a) of the two free end surfaces (14a, 14b) extends in first plane (P1) that has a first acute angle (a) with the longitudinal axis (A) and wherein a second (14b) of the free end surfaces (14a, 14b) extends in a second plane (P2) to a second acute angle (a ') with the longitudinal axis (A).

The sealing sleeve according to claim 3, wherein the first and second sharp angles (a, a) are equal so that the first and the second face (P1, P2) are parallel.

The sealing sleeve according to any of the preceding claims 10 comprising: • a cylindrical core (12) with a core wall that is rigid.

The seal sleeve according to claim 5, wherein the core (12) has two core end surfaces defined by the core wall 15 and each associated with a free end surface (14a, 14b) associated therewith of the seal sleeve wall (14), wherein each core end surface extends in a plane parallel to the plane (P1, P2) in which the associated free end surface (14a, 14b) of the seal cuff wall (14) extends. 20

The seal sleeve according to claim 5 or 6, wherein a portion of (14c) of the seal sleeve wall (14) also extends at least partially on an inner surface of the cylindrical core (12).

The sealing sleeve according to any of claims 1-7, comprising: • threaded holes (18) into which bolts can be screwed to provide a connection between an inner element and the sealing sleeve (10).

The seal sleeve according to claim 8, wherein the threaded holes (18) extend along a screw axis (A2) that includes an acute angle (6) with the longitudinal axis (A) of the seal sleeve wall (14). 5

An assembly of a sealing sleeve (10) according to any one of claims 1-9 and an inner element (100) with an outer surface and an outer element (110) with an inner surface, wherein the inner element (100) can be accommodated in the outer element (110) such that a circumferential space (120) is present which extends in a longitudinal direction and has a radial width which is determined by the distance between the outer surface of the inner element (100) and the inner surface of the outer element ( 110).

An assembly according to claim 10, wherein the inner element (100) is a lining of a covering string and the outer element (110) is a well bore wall.

An assembly according to claim 10, wherein the inner element 20 (100) is a production housing and the outer element (110) is a well borehole covering.

13. An assembly according to claim 10, wherein the outer element (110) is a housing of an apparatus and the inner element (100) is a shaft mounted in the housing.

A method of applying a sealing sleeve between an inner member (100) and an outer member (110), the method comprising: • providing an outer member (110) with a hole with an inner surface; • providing an inner element (100) with an outer surface, the dimensions of the inner element (100) relative to the outer element (110) being such that the inner element (100) can be received in the outer element ( 110); • providing a sealing sleeve (10) according to any of 10. applying the sealing sleeve over the inner element (100); Fixing the sealing sleeve to a longitudinal position on the inner member (100); Inserting the internal element (100) into the hole of the external element (110); • providing a fluid that causes swelling of the swellable polymeric material of the seal sleeve (12).