PLUGGING DEVICE

Abstract

The invention relates to a plugging device (1) comprising a packer device (4) for pressure tight sealing of a pipe. The packer device (4) comprises a first outer packer supporting device (20), a second outer packer supporting device (22) and an outer packer body (50) provided axially between the first packer supporting device (20) and the second packer supporting device (22). The outer packer (50) is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second outer packer supporting devices (20, 22). The packer device 4 further comprises a first inner packer supporting device (12), a second inner packer supporting device (14) and an inner packer body (15) provided axially between the first inner packer supporting device (12) and the second inner packer supporting device (14). The inner packer body (15) is provided radially inside the outer packer body (50) when the outer body is in the radially expanded position. The inner packer body (15) is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second inner packer supporting devices (12) and (14).

Description

FIELD OF THE INVENTION

The present invention relates to a plugging device.

BACKGROUND OF THE INVENTION

Several types of plugging devices for plugging of hydrocarbon well pipes are known. In U.S. Pat. No. 7,178,602 it is shown a plugging device having an anchoring device with gripping elements for anchoring the plugging device to the inner casing of the well pipe to prevent movement of the plugging device. The plugging device also comprises an expandable packer element for sealing the well pipe. The packer element is supported by a link connection for compressing and thereby expanding the packer element radially.

Another plugging device is known from U.S. Pat. No. 7,290,603. Here an expandable packer element is compressed axially by means of two pressure rings, thereby providing a radial expansion of the packer element. Moreover, radially expandable ring elements are provided in order to improve the support the packer element in the expanded position.

A so-called high expansion plugging device has a relatively narrow diameter in retracted position, allowing the plugging device to pass restrictions in the well pipe. At the same time, it has a relatively large diameter in expanded position to seal the well pipe.

In some subsea hydrocarbon well pipes, there is a need for plugging devices which may withstand high pressures and high temperatures for a long time. This puts a lot of stress to the packer element being compressed during the sealing period. Moreover, it is a requirement that the plugging device is retrievable from the well after use. Often there is a risk that the packer element becomes deformed during the expansion, which may cause problems with retrieving the plugging device past narrow restrictions in the well pipe.

One such high pressure, high temperature plugging device is known from U.S. Pat. No. 7,290,603. The plugging device comprises an expandable packer element for sealing against the well pipe, where the packer element is supported by radially expanding seal elements. The seal elements are gliding on respective tapering surfaces of pressure rings located axially on respective sides of the packer element. The pressure rings are moved axially towards each other in order to radially expand the packer element.

The object of the invention is to provide a plugging device which is capable of withstanding a high pressure and a high temperature for a long time and still being able to be retracted after use.

Moreover, one object is to provide a plugging device comprising an inner packer body which provides a pressure tight sealing against an outer packer body or against other outer parts of the plugging device.

SUMMARY OF THE INVENTION

The present invention is related to a plugging device comprising a packer device for pressure tight sealing of a pipe, the packer device comprising:

• • a first outer packer supporting device;
  • a second outer packer supporting device;
  • an outer packer body provided axially between the first packer supporting device and the second packer supporting device, where the outer packer is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second outer packer supporting devices. The packer device comprises:
  • a first inner packer supporting device;
  • a second inner packer supporting device;
  • an inner packer body provided axially between the first inner packer supporting device and the second inner packer supporting device, where the inner packer body is provided radially inside the outer packer body when the outer packer body is in the radially expanded position;

where the inner packer body is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second inner packer supporting devices and.

In one aspect, the inner packer body is compressed against the radial inner surface of the outer packer body or the first or second outer packer supporting device in its radially expanded position.

In one aspect, the first inner packer supporting device comprises a first cone having a tapering surface and a base; the second inner packer supporting device comprises a second cone having a tapering surface and a base; where the inner packer body is provided between the bases of the first and second cones.

In one aspect, a connection device is provided for radial orientation of the first inner packer supporting device in relation to the second inner packer supporting device.

In one aspect, the connection device is limiting the axial movement between the first inner packer supporting device and the second inner packer supporting device.

In one aspect, the connection device comprises a threaded bolt inserted through an opening of the first inner packer supporting device and fastened to a threaded opening of the second inner packer supporting device.

In one aspect, a sliding surface is provided on the first and second packer supporting device for sliding up and down the tapering surface of the first or second inner packer supporting device during the movement between the radially expanded position and the radially retracted position.

DETAILED DESCRIPTION

In the following, embodiments of the present invention will be described in detail with reference to the enclosed drawings, where:

FIGS. 1 and 2 illustrates a perspective view of one embodiment of the plugging device in retracted and expanded position respectively;

FIGS. 3 and 4 illustrates a side view of the packer device of FIG. 1 in retracted and expanded position respectively;

FIGS. 5 and 6 illustrates a perspective view of parts of the packer device of FIGS. 3 and 4 respectively;

FIG. 7 illustrates a side view of the packer device in expanded position;

FIG. 8 illustrates a front supporting device with a packer body and a supporting arm;

FIG. 9 illustrates a front supporting device of FIG. 8 without the packer body;

FIG. 10 illustrates rear supporting device and its supporting arm;

FIG. 11 illustrates the rear supporting device of FIG. 10;

FIG. 12 a illustrates the configuration of the rear supporting devices of the first packer supporting device in the retracted position;

FIG. 12 b is similar to FIG. 12a, where one front supporting device is provided;

FIG. 12 c is similar to FIGS. 12a and 12b, where all front supporting devices are provided;

FIG. 13 a illustrates the configuration of the rear supporting devices of the first packer supporting device in the expanded position;

FIG. 13 b is similar to FIG. 13a, where one front supporting device is provided;

FIG. 13 c is similar to FIGS. 13a and 13b, where all front supporting devices are provided;

FIG. 14 illustrates a side view of some of the front and rear supporting elements of the first and second packer supporting devices in the expanded position;

FIG. 15 illustrates a perspective view of all the front and rear supporting elements of the first and second packer supporting devices in the expanded position;

FIG. 16 illustrates an alternative embodiment of a packer body;

FIG. 17 illustrates an alternative embodiment of a front supporting device, a supporting arm and a packer body.

It is now referred to FIGS. 1 and 2, illustrating an embodiment of the plugging device 1. The plugging device 1 comprises an anchoring device 2, a connection interface 3 and a packer device 4.

The anchoring device 2 comprises gripping devices for fixation of the plugging device 1 to an inner wall of a pipe (not shown). It should be noted that fluid is allowed to pass the plugging device when the anchoring device 2 is set, i.e. in its expanded position shown in FIG. 2. The anchoring device 2 is considered known for a person skilled in the art, for example from the abovementioned publication U.S. Pat. No. 7,178,602 and will therefore not be described here in detail.

The connection interface 3 is provided for connection to a setting tool for bringing the plugging device from its retracted or “run” position to its expanded or “set” position and for connection to a retrieval tool for retrieving the plugging device again after use. The connection interface 3, the setting tool and the retrieval tool are also considered known for a skilled person, and will not be explained in detail here either.

The packer device 4 is provided for pressure tight sealing of the pipe. That is, no fluid is supposed to pass the packer device 4 in the annular space between the outer surface of the plugging device and the inner surface of the wall pipe. It should be noted that the initial design requirement for the plugging device 1 is that it has to pass a restriction with machined inner diameter of 4.125″ (i.e. in retracted position) and is to be set in a 7″35 ppf casing. Moreover, the packer device 4 according to the present invention is to withstand a pressure difference of 5000 psi at a temperature of 170° in the set position. Of course, this initial design requirement does not prevent using the principles of the invention for designing a plugging device for other types of pipes with other diameters, temperatures and pressures.

It is now referred to FIGS. 3, 4 and 7. Here it is shown that the packer device 4 comprises a first outer packer supporting device 20 and a second outer packer supporting device 22. An outer packer body 50 is provided axially between the first outer packer supporting device 20 and the second outer packer supporting device 22, where the outer packer 50 is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second outer packer supporting devices 20, 22. This will be explained more in detail below.

The packer device 4 further comprises a first inner packer supporting device 12 and a second inner packer supporting device 14. An inner packer body is 15 provided axially between the first inner packer supporting device 12 and the second inner packer supporting device 14.

The inner packer body 15 is provided axially displaced in relation to the outer packer body 50 when the outer body is in the radially retracted position, as shown in FIG. 3. As shown in FIG. 7, some parts of the outer packer body 50 (packer elements 50a) are provided on one side of the inner packer body 15 and some parts of the outer packer body 50 is provided on the second side of the inner packer body 15.

The inner packer body 15 is provided radially inside the outer packer body 50 when the outer body is in the radially expanded position, as shown in FIG. 4 and FIG. 7.

The inner packer body 15 is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second inner packer supporting devices 12 and 14.

In FIG. 7, it is shown that the inner packer body 15 is compressed against a radial inner surface of the outer packer body 50 or against a radial inner surface of the first or second outer packer supporting device 20, 22 in its radially expanded position. Hence, one continuous seal is provided in the well flow.

In the present embodiment, the first inner packer supporting device 12 comprises a first cone having a tapering surface 12a and a base 12b. In similar way, the second inner packer supporting device 14 comprises a second cone having a tapering surface 14a and a base 14b. In FIG. 3, it is shown that the base 12b of the first cone is faced towards the base 14b of the second cone. The inner packer body 15 is provided between the bases 12b, 14b of the first and second cones.

A connection device 16 may be provided for radial orientation of the first inner packer supporting device 12 in relation to the second inner packer supporting device 14. The connection device 16 may also be used to limit the axial movement between the first inner packer supporting device 12 and the second inner packer supporting device 14. In the present embodiment the connection device 16 comprises a threaded bolt 17 inserted through an opening 18 of the first inner packer supporting device 12 and fastened to a threaded opening 19 of the second inner packer supporting device 14.

A sliding surface is provided on the first and second packer supporting device 20, 22 for sliding up and down the tapering surface 12a, 14a of the first or second inner packer supporting device 12, 14 during the movement between the radially expanded position and the radially retracted position.

The other elements of the packer device 4 will be described below. It is now referred to FIGS. 3-6. As mentioned, the packer device 4 comprises a cone device 10, a first outer packer supporting device 20 provided on a first side of the cone device 10 and a second a second outer packer supporting device 22 provided on a second side of the cone device 10, opposite of the first side in the longitudinal direction of the plugging device 1 as shown in FIG. 3.

The cone device 10 comprises the abovementioned first cone 12 and second cone 14, each having their base 12b, 14b faced towards each other and each comprising a tapering surface 12a, 14a. In FIG. 3 it can be seen that the base 12b is parallel to the base 14b and that the bases 12b, 14b both are perpendicular to the longitudinal direction of the plugging device. In FIG. 5 it is shown that the base 12b of the first cone 12 is circular. In the present invention, the tapering surfaces 12a, 14a are straight.

In an alternative embodiment, it would be possible to provide the cones 12, 14 with an increasingly tapering surface, or a decreasingly tapering surface i.e. the tapering surface will be curved.

In the present embodiment, the first cone 12 and the second cone 14 is displaceable in an axial direction with respect to each other. A cone packer element 15 is provided between the base of the first cone 12 and the base of the second cone 14. Again, the connection device 16 is provided for radial orientation of the first cone 12 in relation to the second cone 14. The connection device 16 limits the axial displacement of the first cone 12 in relation to the second cone 14.

In the present embodiment, the connection device 16 limits the maximum distance between the base of the first cone 12 and the base of the second cone 14. The compression of the cone packer element limits the minimum distance between the base of the first cone 12 and the base of the second cone 14. However, the connection device 16 may also be used to limit the minimum distance between the base of the first cone 12 and the base of the second cone 14. In the present embodiment the connection device 16 comprises at least one screw (see FIG. 7), or by means of other types of connection means 16 well known for a person skilled in the art.

The first and second packer supporting devices 20, 22 of the present embodiment are equal to each other. Each of the first and second packer supporting devices comprises supporting arms 24 having a first end 24a movably or pivotably connected to the plugging device 1 and a second end 24b movably or pivotably connected to either a front supporting element 30 or a rear supporting element 40. It should be noted that it would be possible to connect the second end 24b of the arm 24 to the front supporting element 30 or the rear supporting element 40 in a fixed way, i.e. they are not movable or pivotable in relation to each other.

In FIG. 8 it is shown a supporting arm 24 having its second end 24b pivotably connected to a front supporting element 30. In FIG. 10 it is shown a supporting arm 24 having its second end 24b pivotably connected to a rear supporting element 40.

The supporting arm 24 can for example be similar to those described in U.S. Pat. No. 7,178,602. The supporting arms are therefore considered known for a skilled person, and will not be described in detail herein. The supporting arms form a continuous outer surface around the plugging device in the retracted position and during expansion to the expanded position, thereby preventing debris etc in the well flow to block the expansion/retraction process. This can for example be seen in FIGS. 5 and 6.

The pivotation of the supporting arm 24 with respect to the plugging device 1 and the front or rear supporting element 30 or 40 may be provided by a pivotation bolt or any other suitable pivotation mechanism or movable mechanism allowing the supporting arm 24 to move radially out from the plugging device 1.

A sliding surface is provided on the first and second packer supporting device 20, 22. The sliding surface may comprise several sliding surfaces which may be provided on the front supporting element 30 and/or rear supporting element 40.

Alternatively, sliding surfaces could be provided on other parts of the first and second packer supporting devices 20, 22, for example as a part of the supporting arms 24.

The sliding surface is provided for sliding up and down the tapering surface 12a, 14a of the first or second cone, i.e. the sliding surface and the tapering surfaces provides that an axial movement of the first and second packer supporting devices 20, 22 causes a radial movement of the front supporting elements 30 and the rear supporting elements 40.

The front supporting element 30 will now be described with reference to FIG. 9. The front supporting element 30 comprises a sliding surface 31 for sliding up and down the tapering surface 12a, 14a of the first or second cone, depending on whether the front supporting element 30 is a part of the first or second packer supporting device 20 or 22 respectively.

The front supporting element 30 further comprises a front surface 32 for supporting a packer body generally denoted with reference number 50. The front surface 32 is faced towards the base of the first and second cones 12, 14, for example as shown in the retracted position in FIG. 5. In the present embodiment, the front surface 32 is substantially parallel to the base of the first and second cones 12, 14, both in the retracted position and in the expanded position. Hence, the front surface 32 is also faced towards the plane formed by the base of the first and second cones 12, 14 in the expanded position, as shown in FIG. 6. More specifically, the front surface 32 of the first packer supporting device 20 is faced towards the plane formed by the base of the second cone 14 and the front surfaces 32 of the second packer supporting device 22 is faced towards the plane formed by the base of the first cone 12, both in the retracted and in the expanded position. In the present embodiment, since the tapered surface 12a, 14a of the cones are straight, the front surface 32 is always perpendicular to the longitudinal direction of the plugging device, i.e. both during retraction and expansion. The front surface 32 is at least partially curved.

The front supporting element 30 also comprises a radial outer surface 33. The radial outer surface 33 is curved, the curve preferably having a radius R (see FIG. 13c) corresponding to the radius of the casing the plugging device is set in.

The front supporting element 30 also comprises a rear surface 34 provided on the rear side of the front surface 32. The rear surface 34 is substantially planar. On the rear surface 34 a supporting body 35 is provided. When viewed from above in FIG. 9, the supporting body 35 is substantially T-shaped, having a stem 35a and a cross bar 35b. A connection interface 36 for pivotably connection to the supporting arm 24 is provided as a part of the cross bar 35b, see for example FIG. 14.

The rear supporting element 40 will now be described with reference to FIG. 11. The rear supporting element 40 also comprises a sliding surface 41 for sliding up and down the tapering surface 12a, 14a of the first or second cone, depending on whether the rear supporting element 40 is a part of the first or second packer supporting device 20 or 22 respectively.

Moreover, the rear supporting element 40 further comprises a substantially planar front surface 42. The front surface 42 is provided for supporting the rear surface 34 of the front supporting element 30 both in the retracted and expanded position.

The rear surface 42 is also faced towards the base of the first and second cones 12, 14, for example as shown in the retracted position in FIG. 5. In the present embodiment, the rear surface 42 is substantially parallel to the base of the first and second cones 12, 14, both in the retracted position and in the expanded position. Hence, the rear surface 42 is also faced towards the plane formed by the base of the first and second cones 12, 14 in the expanded position, as shown in FIG. 6. More specifically, the rear surface 42 of the first packer supporting device 20 is faced towards the plane formed by the base of the second cone 14 and the front surfaces 32 of the second packer supporting device 22 is faced towards the plane formed by the base of the first cone 12, both in the retracted and in the expanded position. In the present embodiment, since the tapered surface 12a, 14a of the cones are straight, the rear surface 42 is always perpendicular to the longitudinal direction of the plugging device, i.e. both during retraction and expansion.

The rear supporting element 40 also comprises a radial outer surface 43. The radial outer surface 43 is curved, the curve preferably having a radius R (see FIG. 13c) corresponding to the radius of the casing the plugging device is set in. Hence, in the expanded position showed in FIG. 13c, the front and rear supporting elements 30, 40 forms a “torus”-like body having a circular radial outer surface.

The rear supporting element 40 also comprises a rear surface 44 provided on the rear side of the front surface 42. On the rear surface 44 a supporting body 45 is provided. A connection interface 46 for pivotably connection to the supporting arm 24 is provided on the rear surface 44, see for example FIG. 14.

It is now referred to FIG. 12a-c and FIG. 13a-c. In FIG. 12a it is shown that nine rear supporting elements 40 are providing a “torus”-like ring when arranged next to each other. Moreover, the sliding surfaces 41 of the rear supporting elements 40 may provide a continuous contact surface towards the cone 12 or 14. In the arrangement shown in FIG. 12a it is shown that a slit 49 is formed between two adjacent rear supporting elements 40. The shape of the slit 49 between two such rear supporting elements 40 is configured to receive the stem 35a of the front supporting element 30, as shown in FIG. 12b.

In FIG. 12c, all nine slits 49 have received one front supporting element 30. Here it is shown that the front surface 42 of one rear supporting element 40 is provided at lest partially behind the rear surfaces 34 of two adjacent front supporting elements 30 in the retracted position. The front surfaces 42 of the rear supporting elements 40 are supporting the rear surfaces 34 of the front supporting elements 30 in the retracted position.

In FIG. 12c it is shown that the sliding surfaces 31 of the front supporting elements 30 may form a substantially continuous contact surface towards the cone 12 or 14.

In the expanded position shown in FIG. 13a, the distance between the rear supporting elements 40 increases as they slide on the tapering surface of the cone 12 or 14. As shown in FIGS. 13b and 13c, there is still contact between the front surfaces 42 of the rear supporting elements 40 and the rear surfaces 34 of the front supporting elements 30 in the expanded position. It should be noted that that the sliding surfaces 31 and 41 of the front and rear supporting elements 30, 40 together may provide a substantially continuous surface towards the cone 12 or 14 in the expanded position, as illustrated in FIG. 13c by the dashed line A.

Moreover, the radial outer surfaces 33, 43 of the front and rear supporting elements 30 and 40 together forms a substantially continuous radial outer surface as illustrated in FIG. 13c by the dashed line B.

From FIGS. 5 and 6 it is clear that every second supporting arm 24 of the first supporting device 20 is pivotably connected to the respective front supporting elements 30 and every second supporting arm 24 is pivotably connected to the respective rear supporting elements 40. This is also the case for the second supporting device 22.

It is now referred to FIGS. 14 and 15. Here it is shown that the first and second packer supporting device 20, 22 are configured so that each front surface 32 of the front supporting elements 30 of the first outer packer supporting device 20 is faced towards a front surface 42 of the rear supporting elements 40 of the second outer packer supporting device 22 in the expanded position. Consequently, each front surface 32 of the front supporting elements 30 of the second outer packer supporting device 22 is faced towards a front surface 42 of the rear supporting elements 40 of the first outer packer supporting device 20 in the expanded position.

In FIG. 14 it is shown that the straight dashed line D is going through both the centre of the front surface 32 of the front supporting element 30 and the centre of the front surface 42 of the rear supporting element 40.

In the first embodiment shown in FIGS. 3-8, the outer packer body 50 comprises packer elements 50a provided on the front surface 32 of each front supporting element 30. The packer element 50a is made of a ductile material, such as an elastomeric material and/or a rubber material etc, which may withstand the pressure and temperature required for the well pipe being sealed. The packer element 50a may be molded onto the front supporting element 30. In the present embodiment, the radial inner part 51 of each packer element 50a is protruding in an axial direction in relation to the radial outer part 52 (see FIG. 8). In this way the radial inner part 51 will be pressed downwards toward the cone device in the expanded position.

The plugging device may be provided with a guiding system for preventing relative rotation between the first and second packer supporting devices 20, 22 during expansion and retraction. In FIG. 7 it is shown a guiding pin 28 provided in a guiding groove (not shown) preventing a relative rotation between the first and second packer supporting devices 20, 22.

The operation of the packer device 4 will now be described. The packer device 4 is initially in its retracted position. A retracting device 60 (see FIG. 7), for example a spring etc may be provided for bringing the first and second packer supporting devices 20, 22 back to their retracted position. The retracting device 60 is in one end fixed to the supporting arm 24 and in the other end to the respective first or second part 1a, 1b of the plugging device, as shown in FIG. 7. It should be noted that the packer element 50a is not stressed in the retracted position.

For bringing the packer device 4 to its expanded position, a first part 1a of the plugging device 1 is pressed towards a second part 1b of the plugging device (see FIG. 7), as is known for a skilled person. The guiding system prevents a relative rotation between the first part 1a and the second part 1b. Consequently, the sliding surfaces 31, 41 of the front and rear supporting elements 30, 40 starts to slide on the tapering surfaces 12a, 14a of the cones 12, 14 as they pivot with respect to the supporting arms 24.

In the expanded position, the packer element 50a is pressed between the front surface 32 of the front supporting elements 30 and the front surface 42 of the rear supporting elements 40. Hence, the front surface 42 of the rear supporting element 40 is configured to support a packer element 50a of the opposite packer supporting device 20, 22 when in the expanded position.

As shown in FIG. 4, the packer elements 50a form a continuous packer around the packer device 4, where every second packer element 50a is fixed to the first outer packer supporting device 20 and every second packer element 50a is fixed to the second outer packer supporting device 22.

In FIG. 15 it is shown that the front surfaces 32, 42 together have a form similar to a circular ring. This circular surface forms an extrusion barrier surface for the outer packer body 50. The outer packer body 50 will form a seal towards the pipe in the expanded position, and the extrusion barrier surface prevents the extrusion of the outer packer body 50. Moreover, the expansion will also provide that the first cone 12 is displaced towards the second cone 14, thereby providing a compression of, and a radial expansion of, the cone packer element 15. Hence, the cone packer element 15 will be pressed towards the outer packer body 50 along its radial periphery. Hence, a continuous ductile seal is provided in the pipe by the cone packer element 15 and the outer packer body 50.

In FIG. 14 the central line between the front and rear supporting elements of the respective first and second supporting devices 20, 22 is illustrated by the dashed line C. The curved shape of the front surface 32 of the front supporting elements 30 provides that the opening for the outer packer body 50 between the first supporting device 20 and the second supporting device 22 is approximately the same around the periphery. Hence, the stress on the outer packer body 50 is substantially similar around the periphery.

When the packer device 4 is to be retracted, the first part 1a of the plugging device 1 is pulled away from the second part 1b of the plugging device 1, as is familiar for a skilled person. The sliding surfaces 31, 41 will now slide down on the tapering surfaces of the cones 12, 14 due to the force applied by the retracting device 60, thereby pressing the supporting arms 24 radially inwards. The first part 1a is pulled away from the second part 1b until the maximum distance between the base of the first cone 12 and the base of the second cone 14 is reached due to the connection device 16. Then the plugging device 1 has reached the retracted position and may be retrieved from the well pipe.

In the first embodiment described above, the outer packer body 50 comprised several packer elements 50a. However, in a second embodiment, the outer packer body 50 may be provided as one packer element 50b. In FIG. 16 one embodiment of such a packer element 50b is illustrated. The packer element 50b comprises one continuous packer which is folded to allow it to expand and retract. The packer element 50b comprises nine folds 53 which may be fixed to the respective nine front supporting elements 30 of one of the packer supporting devices 20, 22. In yet an alternative embodiment the outer packer body 50 could comprise two or more such packer elements 50b, each fixed to each other and/or the front supporting elements 30 of the first and second packer supporting device 20, 22 respectively.

Another embodiment is illustrated in FIG. 17. Here, the outer packer body 50 comprises several packer elements 50c. The packer elements 50c is, as the packer elements 50a described above, made of a ductile material. However, in this embodiment each packer element 50c is connected to the front surface 32 of the front supporting element 30 by means of a sliding dove-tail joint 54. The packer element 50c also provided with pieces 55 of a plastic deformable material, a more rigid material than the ductile material. As shown in FIG. 17, the part of the packer element 50c which forms the dovetail joint is made of the plastic deformable material. The dovetail joint 54 allows the packer element 50c to slide radially out towards the inner surface of the pipe in the expanded position, to improve the seal in cases where the pipe has been deformed. The dove-tail joint 54 comprises stopping means to limit the radial movement of the packer element 50c in relation to the front supporting element 30.

Even though the description above have been focused on a plugging device for hydrocarbon well pipes, it should be noted that the plugging devices could also be used for plugging other types of pipes, for example water pipes etc.

Claims

1. A plugging device comprising a packer device for pressure tight sealing of a pipe, the packer device comprising: a first outer packer supporting device;a second outer packer supporting device;an outer packer body provided axially between the first outer packer supporting device and the second outer packer supporting device, wherein the outer packer body is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second outer packer supporting devices;a first inner packer supporting device;a second inner packer supporting device; andan inner packer body provided axially between the first inner packer supporting device and the second inner packer supporting device, wherein the inner packer body is provided radially inside the outer packer body when the outer packer body is in the radially expanded position,wherein the inner packer body is movable between a radially retracted position and a radially expanded position by an axial movement between the first and second inner packer supporting devices.

2. The plugging device according to claim 1, wherein the inner packer body is compressed against a radial inner surface of the outer packer body or the first or second outer packer supporting devices when in the radially expanded position.

3. The plugging device according to claim 1, wherein: the first inner packer supporting device comprises a first cone having a tapering surface and a base;the second inner packer supporting device comprises a second cone having a tapering surface and a base; andthe inner packer body is provided between the bases of the first and second cones.

4. The plugging device according to claim 1, wherein a connection device is provided for radial orientation of the first inner packer supporting device in relation to the second inner packer supporting device.

5. The plugging device according to claim 4, wherein the connection device is configured to limit the axial movement between the first inner packer supporting device and the second inner packer supporting device.

6. The plugging device according to claim 4, wherein the connection device comprises a threaded bolt inserted through an opening of the first inner packer supporting device and fastened to a threaded opening of the second inner packer supporting device.

7. The plugging device according claim 3, wherein a sliding surface is provided on the first and second packer supporting devices and is configured to slide up and down the tapering surfaces of the first or second inner packer supporting devices during the movement between the radially expanded position and the radially retracted position.

8. The plugging device according to claim 2, wherein: the first inner packer supporting device comprises a first cone having a tapering surface and a base;the second inner packer supporting device comprises a second cone having a tapering surface and a base; andthe inner packer body is provided between the bases of the first and second cones.

9. The plugging device according to claim 2, wherein a connection device is provided for radial orientation of the first inner packer supporting device in relation to the second inner packer supporting device.

10. The plugging device according to claim 3, wherein a connection device is provided for radial orientation of the first inner packer supporting device in relation to the second inner packer supporting device.

11. The plugging device according to claim 5, wherein the connection device comprises a threaded bolt inserted through an opening of the first inner packer supporting device and fastened to a threaded opening of the second inner packer supporting device.

12. The plugging device according to claim 4, wherein a sliding surface is provided on the first and second packer supporting device and is configured to slide up and down the tapering surfaces of the first or second inner packer supporting devices during the movement between the radially expanded position and the radially retracted position.

13. The plugging device according to claim 5, wherein a sliding surface is provided on the first and second packer supporting device and is configured to slide up and down the tapering surfaces of the first or second inner packer supporting devices during the movement between the radially expanded position and the radially retracted position.

14. The plugging device according to claim 6, wherein a sliding surface is provided on the first and second packer supporting device and is configured to slide up and down the tapering surfaces of the first or second inner packer supporting devices during the movement between the radially expanded position and the radially retracted position.