WO2013095092A1

WO2013095092A1 - Seal sleeve and method for applying such a seal sleeve

Info

Publication number: WO2013095092A1
Application number: PCT/NL2012/050813
Authority: WO
Inventors: Roger Wilfred HIBBERD
Original assignee: Ruma Products Holding B.V.
Priority date: 2011-11-18
Filing date: 2012-11-16
Publication date: 2013-06-27
Also published as: NL2007811C2

Abstract

Seal sleeve and method for applying such a seal sleeve A seal sleeve (10, 50) having a seal sleeve wall (12, 52) comprising a swelling polymer material having elastomeric properties so that the seal sleeve has non-swollen state and an expanded state, wherein the seal sleeve wall has a closed circumference that extends around a central longitudinal axis (A), the seal sleeve wall having a non-swollen thickness and an expanded thickness that are defined by the distance between an inner surface and an outer surface of the seal sleeve in the two respective states, the seal sleeve wall being flexible so that it can be compressed from a relaxed state towards a compressed state, the seal sleeve wall having in the relaxed state a relaxed internal diameter and having in the compressed state a compressed internal diameter, wherein the relaxed internal diameter is smaller than the compressed internal diameter of the seal sleeve wall.

Description

Title: Seal sleeve and method for applying such a seal sleeve

Technical Field

The invention relates to a sealing sleeve having a seal sleeve wall that includes swelling polymer material and to a method for applying a seal sleeve on an inner element.

Background

A swelling seal sleeve is known from e.g. WO03/008756,

WO06/003113 and US2007/0056735. In all these publications the seal sleeves 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.

Generally, such seal sleeves are applied on an inner element that has an outer diameter that is approximately equal to the internal diameter of the sleeve.

Summary of the Invention

In some cases, the inner element has on its ends an increased outer diameter. For example, production tubulars for an oil well may have such a configuration. Such production tube has a constant outer diameter along a major part of its length except for the end parts of the production tube that have an increased diameter.

It is an object of the present invention to provide a seal sleeve that can easily be mounted on an inner element. More specifically, it may be an additional object to provide a seal sleeve that can be mounted on an inner element having end parts that have an increased diameter relative to the diameter of the inner element along the remaining major length of the inner element.

To that end, the invention provides a seal sleeve having a seal sleeve wall comprising a swelling polymer material having elastomeric properties so that the seal sleeve has non-swollen state and an expanded state, wherein: the seal sleeve wall has a closed circumference that extends around a central longitudinal axis and that has a certain length in the direction of the central axis that extends in the longitudinal direction, the seal sleeve wall defining an internal diameter;

the seal sleeve wall has a non-swollen thickness that is defined by the distance of an inner surface and an outer surface of the seal sleeve wall in the non-swollen state;

• the seal sleeve wall has an expanded thickness that is defined by the distance between the inner surface and the outer surface of the seal sleeve wall in the expanded state;

characterized in that the seal sleeve wall is flexible so that it can be

compressed from a relaxed state towards a compressed state, the seal sleeve wall having in the relaxed state a relaxed internal diameter and having in the compressed state a compressed internal diameter, wherein the relaxed internal diameter is smaller than the compressed internal diameter of the seal sleeve wall.

By virtue of the fact that the sleeve wall is flexible so that it can be compressed from a relaxed state towards a compressed state, in which compressed state the compressed internal diameter of the seal sleeve wall is larger than the relaxed internal diameter that the seal sleeve wall has when it is not compressed, the seal sleeve can in a compressed state be shifted over an inner element that has at some zones, for example its end zones, an increase diameter relative to the outer diameter along the major part of its length. Consequently, the seal sleeve according to the invention can, for example, be applied with well tubulars that have ends with enlarged diameters.

The invention also provides a method for applying a seal sleeve on an inner element. The method includes:

providing a inner element having an outer diameter; - providing a seal sleeve according to any of the preceding claims having a relaxed internal diameter that is equal to or just slightly less than the outer diameter of the inner element;

- compressing the seal sleeve wall of the seal sleeve so as to bring the seal sleeve wall in the compressed state;

- shifting the seal sleeve that is in the compressed state over the inner element;

- stop the compression of the seal sleeve wall so as to bring the seal sleeve wall in the relaxed state in which it engages an outer surface of the inner element and is positioned on the inner element.

With this method, an extremely simple mounting of an seal sleeve is obtained even on an inner element that has parts with increased diameters near its longitudinal ends.

Further embodiments are described in the dependent claims and will be further elucidated with reference to three examples of two

embodiments that are shown in the figures.

Brief Description of the Drawings

Fig. 1 shows a first perspective view of an assembly of an inner element, an example of a first embodiment and an example of a second embodiment;

Fig. 2 shows a second perspective view of the assembly shown in

Fig. 1;

Fig. 3 shows a front view of the assembly shown in Figs. 1 and 2; Fig. 4 shows a top view of the assembly shown in Figs. 1 and 2;

Fig. 5 shows a side view of the assembly shown in Fig. 3;

Fig. 6 shows a front view of an example of a first embodiment of a seal sleeve in the relaxed state;

Fig. 7 shows a side view of Fig. 6;

Fig. 8 shows a top view of Fig. 6; Fig. 9 shows a view in the direction of arrow IX in Fig. 6;

Fig. 10 shows a perspective view of the example of the seal sleeve of

Fig. 6;

Fig. 11 shows a front view of the example of Fig. 6 in a compressed state;

Fig. 12 shows a side view along arrow XII in Fig. 11;

Fig. 13 shows a perspective view of the compressed seal sleeve of

Fig. 11;

Fig. 14 shows a front view from an example of a second embodiment of a seal sleeve;

Fig. 15 shows a side view of Fig. 14;

Fig. 16 shows a top view in the direction of arrow XVI in Fig. 14;

Fig. 17 shows a view in the direction of arrow XVII in Fig. 6;

Fig. 18 shows a perspective view of the example of the seal sleeve shown in Figs. 14-17;

Figs. 19 shows an example of an embodiment of an expandable stent structure.

Detailed Description

Figs. 1-5 show various views as described above of an assembly. The assembly includes an inner element 100 having an outer diameter Do along a major part of its length. At the longitudinal ends of the inner element 100, the inner element 100 has parts 110 of which the diameter Di is increased relative to the outer diameter Do. All Figs. 1-5 show an example of a first embodiment of a seal sleeve 10 in a relaxed state positioned approximately at the middle of the inner element. The same type of seal sleeve 10 is also depicted in the compressed state at the left end of the inner element 100 around the left end part 110 with increased diameter Di. At the right of the first embodiment of the seal sleeve 10, a second exemplary embodiment of a seal sleeve 50 is shown that is in the relaxed state. For both exemplary embodiments it is valid to say that, the seal sleeve 10, 50 has a seal sleeve wall 12, 52 comprising a swelling polymer material having elastomeric properties so that the seal sleeve has non-swollen state and an expanded state. The seal sleeve wall 12, 52 has a closed

circumference that extends around a central longitudinal axis A and that has a certain length in the direction of the central axis A that extends in the longitudinal direction LD. The seal sleeve wall 12, 52 defining an internal diameter. The seal sleeve wall 12, 52 has a non-swollen thickness Tn that is defined by the distance of an inner surface and an outer surface of the seal sleeve wall 12, 52 in the non-swollen state. The seal sleeve wall 12, 52 has an expanded thickness (not shown) that is defined by the distance between the inner surface and the outer surface of the seal sleeve wall 12, 52 in the expanded state. In general, the seal sleeve wall 12, 52 is flexible so that it can be compressed from a relaxed state towards a compressed state. In the relaxed state, the seal sleeve wall 12, 52 has a relaxed internal diameter dr. In the compressed state, the seal sleeve wall 12, 52 has a compressed internal diameter dc. The relaxed internal diameter dr is smaller than the compressed internal diameter dc of the seal sleeve wall 12, 52. By virtue thereof, it is possible to shift the seal sleeve 10, 50 over the end parts 110 of the inner element 100 in the compressed state.

In the first exemplary embodiment of the seal sleeve 10, the seal sleeve wall 12, 52 includes one annular element 10 that extends along an annular path. The annular path extends in a plane PI that includes an angle a with the central axis A. The angle a is in the range of 20-60°, so that a cross section of the annular element 10 over the plane PI is elliptical having an elliptical inner edge 14 that defines an elliptical central opening 16. The inner edge 14 has a circumferential length that is larger than the π times the relaxed internal diameter dr.

In the second exemplary embodiment of the seal sleeve 50, the seal sleeve wall 52 includes at least two annular elements 50a, 50b that are integrally connected with each other at a connection zone 54. Each annular element 50a, 50b extends along an associated annular path, wherein a first one of the annular paths extends in a first plane PI and a second one of the annular paths extend in a second plane P2. Both planes PI, P2 intersect along an intersection line S. The intersection line S also insects the connection zone 54. The first plane PI includes an angle a with the central axis A that is in the range of 20-60°. The second plane P2 includes an angle β with the central axis A that in the range of 20-60°, so that the cross section of a said annular element 50a, 50b along its associated plane PI, P2 is elliptical defining having an elliptical inner edge 58 that defines an elliptical central opening 56. The inner edge 58 has a circumferential length that is larger than π times the relaxed internal diameter dr. In the second embodiment of which an example is shown in the figures 15-18, the intersection line S of the two planes PI, P2 intersects the central axis A and extends in a radial plane Pr that includes the central axis A.

In an alternative example of the second embodiment that is not shown in the figures, the intersection line S of the two planes PI, P2 may extend parallel to and offset from a radial plane Pr that includes the central axis A.

In yet another embodiment of the seal sleeve according to the invention, the seal sleeve wall 12 may have a structure that is known per se from expandable stent technology. An example of such a seal sleeve 150 with expandable stent configuration is shown in Figs. 19.

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, alkahne or acid fluids. Examples of suitable rubber materials are ethylene propylene rubber (EPM and EPDM), ethylene- propylene-diene terpolymer rubber (EPT), butyl rubber (IIR), brominated butyl rubber (BUR), chlorinated butyl rubber (CIIR); chlorinated polyethylene (CM/CPE); neoprene rubber (CR);

epichlorohydrin ethylene oxide copolymer (CO, ECO); styrene butadiene copolymer rubber (SBR); sulphonated polyethylene (CSM); ethylene acrylate rubber (EAM/AEM); sihcone rubbers (VMQ); and fluorsilicone 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 ZETPOLTM, TORNAC™, TERBANTM_; NBR with reactive groups (X-NBR); perfluoro rubbers (FFKM) such as KALREZ™, CHEMRAZ™; fluoro rubbers (FKM), such as VITONTM, FLUORELTM_{; a}nd 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).

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™,

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.

The seal sleeve according to the invention can be apphed in a method for mounting a seal sleeve 10, 50 on an inner element 100. The method may include:

- providing an inner element 100 having an outer diameter Do,

- providing a seal sleeve 10, 50 according to the invention having a

relaxed internal diameter dr that is equal to or just slightly less than the outer diameter Do of the inner element 100; - compressing the seal sleeve wall 12, 52 of the seal sleeve 10, 50 so as to bring the seal sleeve wall 12, 52 in the compressed state;

- shifting the seal sleeve 10, 50 that is in the compressed state over the inner element 100;

- stopping the compression of the seal sleeve wall 12, 52 so as to bring the seal sleeve wall 12, 52 in the relaxed state in which it engages an outer surface of the inner element 100 and is positioned on the inner element 100.

In an embodiment of the method, the compressing of the seal sleeve wall 12, 52 is such that the elliptical central opening 16, 56 of the at least one annular element 10, 50a, 50b is deformed to a substantially circular central opening having a compressed internal diameter dc that is larger than the relaxed internal diameter dr. When the inner element 100 is a rigid tube having outer end parts 110 with an increased diameter Di relative to the outer diameter Do of the inner element 100, the compressed internal diameter dc of the seal sleeve 10, 50 has to be larger than the increased diameter Di of the outer end parts 110. By virtue thereof, the seal sleeve 10, 50 can be shifted over the end parts 110 when the seal sleeve 10, 50 is in the compressed stated. After having passed the end parts 110, the compression force may be released so that the seal sleeve 10, 50 returns to the relaxed state so that the seal sleeve 10, 50 again takes its original form with the relaxed internal diameter dr that is smaller than the compressed internal diameter dc. In that relaxed state, the seal sleeve 10, 50 may be fixedly positioned on the internal element 100.

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 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

embodiment" in various places throughout this specification are not

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

1. A seal sleeve (10; 50) having a seal sleeve wall (12; 52) comprising a swelling polymer material having elastomeric properties so that the seal sleeve has non-swollen state and an expanded state, wherein:

• the seal sleeve wall (12; 52) has a closed circumference that

extends around a central longitudinal axis (A) and that has a certain length in the direction of the central axis (A) that extends in the longitudinal direction (LD), the seal sleeve wall (12; 52) defining an internal diameter;

• the seal sleeve wall (12; 52) has a non-swollen thickness (Tn) that is defined by the distance between an inner surface and an outer surface of the seal sleeve wall (12; 52) in the non-swollen state;

• the seal sleeve wall (12; 52) has an expanded thickness (Te) that is defined by the distance between the inner surface and the outer surface of the seal sleeve wall (12; 52) in the expanded state;

characterized in that the seal sleeve wall (12; 52) is flexible so that it can be compressed from a relaxed state towards a compressed state, the seal sleeve wall (12; 52) having in the relaxed state a relaxed internal diameter (dr) and having in the compressed state a compressed internal diameter (dc), wherein the relaxed internal diameter (dr) is smaller than the compressed internal diameter (dc) of the seal sleeve wall (12; 52).

2. A seal sleeve (10) according to claim 1, wherein the seal sleeve wall (12) includes at least one annular element (10) that extends along an annular path which annular path extends in a plane (PI) that includes an angle (a) with the central axis (A), which angle (a) is in the range of 20-60°, so that a cross section of the annular element (10) over the plane (PI) is elliptical having an elliptical inner edge (14) that defines an elliptical central opening (16), the inner edge (14) having a circumferential length that is larger than π times the relaxed internal diameter (dr).

3. A seal sleeve (50) according to claim 1, wherein the seal sleeve wall

(52) includes at least two annular elements (50a, 50b) that are integrally connected with each other at a connection zone (54) and that each extend along an associated annular path, wherein a first one of the annular paths extends in a first plane (PI) and a second one of the annular paths extend in a second plane (P2), wherein both planes (PI, P2) intersect along an intersection line (S), wherein the intersection line (S) also insects the connection zone (54), wherein the first plane (PI) includes an angle (a) with the central axis (A) that is in the range of 20-60°, wherein the second plane (P2) includes an angle (β) with the central axis (A) that in the range of 20-60°, so that the cross section of a said annular element (50a, 50b) along its associated plane (PI, P2) is elliptical defining having an elliptical inner edge (58) that defines an elliptical central opening (56), the inner edge (58) having a circumferential length that is larger than π times the relaxed internal diameter (dr)

4. A seal sleeve according to claim 3, wherein the intersection line (S) of the two planes (PI, P2) intersects the central axis (A) and extends in a radial plane (Pr) that includes the central axis (A).

5. A seal sleeve according to claim 3, wherein the intersection line (S) of the two planes (PI, P2) extends parallel to and offset from a radial plane

(Pr) that includes the central axis (A).

6. A seal sleeve according to claim 1, wherein the seal sleeve wall (12) has a structure that is known from expandable stent technology.

7. A method for applying a seal sleeve (10; 50) on an inner element (100), the method including:

- providing a inner element (100) having an outer diameter (Do);

- providing a seal sleeve (10; 50) according to any of the preceding claims having a relaxed internal diameter (dr) that is equal to or just slightly less than the outer diameter (Do) of the inner element (100);

- compressing the seal sleeve wall (12; 52) of the seal sleeve (10; 50) so as to bring the seal sleeve wall (12; 52) in the compressed state;

- shifting the seal sleeve (10; 50) that is in the compressed state over the inner element (100);

- stopping the compression of the seal sleeve wall (12; 52) so as to bring the seal sleeve wall (12; 52) in the relaxed state in which it engages an outer surface of the inner element (100) and is positioned on the inner element (100).

8. A method according to claim 7, wherein the seal sleeve (10; 50) that is provided is a seal sleeve according to any one of claims 2-5, wherein the compressing of the seal sleeve wall (12; 52) is such that the elliptical central opening (16; 56) of the at least one annular element (10; 50a, 50b) is deformed to a substantially circular central opening having a compressed internal diameter (dc) that is larger than the relaxed internal diameter (dr).

9. A method according to claim 7 or 8, wherein the inner element (100) is a metal tube having an outer ends with an increased diameter (Di) relative to the outer diameter (Do) of the inner element (100), wherein the increased diameter (Di) is smaller than the compressed internal diameter (dc).