1. Technical field

The present invention relates to a sealing basket for sealing a space between a first tube and a second tube, particularly in the field of oil extraction. Further, the present invention relates to a respective method and a respective system.

2. Prior art

In the field of oil extraction, particularly in the field of offshore oil production, safety is highly relevant. Oil rigs are often installed far offshore, making it complicated to rescue a crew in case of an acute hazardous situation. Further, the limited space on the oil rig bears the risk of not being able to escape from burning substances or escaping gas. Moreover, measures for damage repair and/or limitation are related with considerable effort and are often complicated to implement. Exemplary, for fire extinguishing that cannot be carried out locally on the oil rig, fire-fighting boats and/ or helicopters are required.

Furthermore, an oil and/or gas leak under the water surface is much more difficult to control and seal than on the earth's surface, e.g. in a desert. In addition, the environmental damage in the event of an oil spill offshore is often greater since the oil can spread unhindered in the sea and local soil cleanup is not possible as it is on land. These aspects became particularly apparent during the sealing of the Deepwater Horizon oil leak in 2010 and the respective oil spill.

A particular critical region in offshore and/ or under water applications is where a first tube that conducts oil is surrounded by another, second tube, which, e.g. serves to stabilize the borehole and/or to protect the first, oil-conducting tube. When the oilconducting tube is surrounded by another tube, an inspection of the oil-conducting tube is not or only partially possible, due to the impeded accessibility for robots and/or divers with respective equipment. Hence, this region has to be reliably sealed. One way to solve this problem is to fill the space between the inner, i.e. oil-conducting tube, and the outer tube with a filling medium such as cement. Using the terminology of oil drilling technology, the space between the inner tube and the outer tube may be referred to as annulus. Thus, corrosion of the inner tube and/or oil leakage can be effectively prevented.

However, a further problem is that the space between the inner tube and the outer tube must be sealed such that the filling medium fills a defined section and does not spread into the surrounding area, as this would negatively affect the sealing or even prevent a proper sealing. This is generally not a problem if the space between the inner tube and the outer tube is naturally sealed, e.g. by a solid seabed. But if for example the outer tube ends above the seabed as seen from the oil platform the liquid filling medium must be prevented from flowing unhindered into the sea. Likewise, it must be prevented, for example, that the filling medium spreads between the inner tube and a larger drilled hole if the outer tube ends below the earth's surface before the inner tube ends. Accordingly, a respective sealing element is required.

When attempting to seal the space between the inner tube and the outer tube by means of a sealing element it is a problem that filling mediums, such as cement, have a high density and the sealing element therefore must withstand high forces. Further, the center axes of the tubes are often inclined and/or offset to each other so that the proper sealing becomes difficult. These deviations in the alignment of the tubes must be compensated by a sealing element.

It is therefore an object underlying the present invention to provide an improved sealing element which allows to seal a space between an inner tube and an outer tube for different tube arrangements, particularly for filling mediums with high densities.

3. Summary of the invention

This object is at least partially achieved by the subject-matter of the independent claims and in particular by a sealing basket for sealing a space between a first tube and a second tube, according to claim 1. Further embodiments of the present invention are defined in the dependent claims.

Particularly, the object is at least partially achieved by a sealing basket for sealing a space between a first tube and a second tube, wherein the first tube at least partially extends within the second tube and wherein the sealing basket comprises a mounting segment which is configured for being mounted on an outside portion of the first tube and an annular segment, having a first end portion and a second end portion. The annular segment having a tapered region located between the second end portion and the first end portion. Further, the first end portion is connected to the mounting segment, so that the annular segment is pivotably with respect to the mounting segment. The second end portion of the annular segment is configured to be in contact with an inner surface of the second tube to seal the space between the first tube and the second tube.

The space between the inner tube and the outer tube may be referred to as annulus, particularly when using the terminology of oil drilling technology. Further details on the first tube and the second tube as well as their configurations are provided below regarding the description of the system according to the present invention.

The mounting segment may be sealingly mounted on the outside portion of the first tube. Further, the mounting segment may have an annular shape. Optionally, the mounting segment has a shape of a hollow cylinder. The mounting segment in shape of a hollow cylinder may comprise at least two segments in an axial direction and/ or perpendicular to the axial direction. Further, the mounting segment maybe provided with seals which are configured for being in contact with an outside portion of the first tube. Moreover, the mounting segment and the annular segment may form a through hole. The mounting segment may have an inner diameter in a range between io cm and 30 cm, optionally between 15 cm and 25 cm, further optionally between 18 cm and 22 cm.

The annular segment may be sealingly connected to the mounting segment. Further, the annular segment has tapered region located between the second end portion and the first end portion. The tapered region may extend from the second end portion to the first end portion. Alternatively, the tapered region maybe present only in a partial section between the second end portion and the first end portion. Even further, the annular segment may have multiple tapered regions (at least two), providing for a stepwise tapering of the annular segment between the second end portion and the first end portion. Thus, a volume to be filled and/or sealed between the first tube and the second tube may taper towards the first tube. Particularly, the volume to be filled and/ or sealed may taper towards the first tube seen from a filling direction (i.e. from the second end portion towards the first end portion of the annular segment). Thus, the volume may be easily filled and/ or an improved load distribution may be achieved.

The term “annular” may include circular shapes, oval shapes and/or shapes which are substantially formed circularly. At the second end portion the annular segment may have an equivalent diameter in a range between 20 cm and 45 cm, optionally between 25 cm and 40 cm, further optionally between 30 cm and 35 cm, wherein the term equivalent diameter corresponds to a diameter of a circle with an equal aggregate sectional area as the annular segment at its second end portion. The equivalent diameter of a circle corresponds to the diameter of said circle. Further, at the first end portion the annular segment may have an equivalent diameter in a range between 10 cm and 30 cm, optionally between 15 cm and 25 cm, further optionally between 18 cm and 22 cm.

A surface of the annular segment between the first end portion and the second end portion may be inclined by an angle between 3 degrees and 25 degrees, optionally between 5 degrees and 20 degrees, further optionally between 7 degrees and 15 degrees, and even further optionally between 8 degrees and 12 degrees relative to a center axis of the annular segment. Thus, the load capacity of the sealing basket may be optimized. This is as an instability of the annular segment may be avoided.

A center axis of the first tube and a center axis of the second tube may be inclined and/ or offset relative to each other. The annular segment being pivotably with respect to the mounting segment may be configured to compensate an inclination and/or an offset between the first tube and the second tube. The annular segment may pivot in each direction relative to the mounting segment (and accordingly, when being mounted on the outside portion of the first tube, relative to the first tube) by at least 1 degree, optionally at least 3 degrees, further optionally at least 5 degrees and even further optionally at least 10 degrees. Thus, different tube configurations may be sealed by the sealing basket. Further, the annular segment maybe flexible so that a center axis the first end portion may be radially offset and/or inclined from a center axis of the second end portion. Thus, the sealing basket may provide for a proper sealing in case the center axes of the first and second tube are inclined and/or offset relative to each other.

The term “sealing” may refer to a medium against which a sealing effect is to be achieved. The sealing basket may seal the space between the first tube and the second tube against cement. The sealing basket may be permeable for water and/or air. This may facilitate the filling of the sealing basket. The sealing basket may be configured for receiving a filling medium, so that the filling medium is in contact with the outside portion of the first tube and the inner surface of the second tube at least in proximity to the second end portion of the annular segment. The filling medium may be a curable material. Further the filling medium may be a cement material, such as a polymer cement, a hydraulic cement, a Portland cement, a Portland cement blend and/ or fiber reinforced cement.

The annular segment may include an annular sealing member that comprises an elastic material, such as a rubber-based material, an elastomer material, a thermoplastic material, a thermoset material, a fiber reinforced composite material and/or a fabric material.

As the annular sealing member has a tapered region located between the second end portion and the first end portion, the volume to be filled and/or sealed between the first tube and the second tube tapers likewise from the inner wall of the second tube towards the outer wall of the first tube. Particularly, the volume to be filled and/or sealed may taper towards the first tube seen from the filling direction. Thus, the volume may be easily filled and/or an improved load distribution may be achieved.

The fiber reinforced composite material may comprise fibers such as glass fibers, carbon fibers and/or aramid fibers. The fibers maybe short fibers, unidirectional fibers woven fibers and/or knitted fibers. The fibers maybe of natural origin and/or synthetized. The fibers may be embedded in an elastic material, such as a rubber-based material, an elastomer material, a thermoplastic material, a thermoset material. Thus, the properties of the sealing member maybe adapted to a particular filling medium. High strength carbon fibers may be used if a cement with a high density is used as filling medium.

The annular sealing member may be configured to be pressed against the mounting element. Moreover, the annular sealing member may be configured to be pressed against an outside portion of the first tube. Further the annular sealing member may be configured to be in contact with the inner surface of the second tube to seal the space between the first tube and the second tube. Thereby an improved sealing behavior may be achieved.

A surface of the annular sealing member between the first end portion and the second end portion maybe inclined by an angle between 3 degrees and 25 degrees, optionally between 5 degrees and 20 degrees, further optionally between 7 degrees and 15 degrees, and even further optionally between 8 degrees and 12 degrees relative to a center axis of the annular sealing member. Thus, the load capacity of the sealing basket may be optimized. This is as an instability of the annular sealing member may be avoided. The annular segment may comprise at least one first stabilizing member being attached to an inside surface and/ or an outside surface of the annular sealing member, wherein the at least one first stabilizing member has an annular shape and, wherein optionally the first end portion and the second end portion are spaced from each other by a distance X and the first stabilizing member is displaced from the second end portion by at most X/2, optionally at most X/3, further optionally at most X/4, and even further optionally at most X/5.

The at least one first stabilizing member may stabilize the shape of the annular sealing member. Therefore, the load capacity of the sealing basket may be increased. Further, the at least one first stabilizing member maybe configured to pretension the annular sealing member against the inner surface of the second tube. Thus, a better sealing may be achieved. Moreover, with the displacement of the at least one first stabilizing member from the second end portion as above mentioned, an improved shape stabilization and an improved pretension may be achieved for the annular sealing member.

The annular segment may comprise at least one second stabilizing member being attached to an inside surface and/or an outside surface of the annular sealing member, wherein the at least one second stabilizing member extends substantially in a straight direction, wherein optionally the at least one second stabilizing element and a center axis of the annular sealing member substantially lie in one plane.

The at least one second stabilizing member may stabilize the annular sealing member against buckling. This may be particularly relevant for higher pivoting angles of the annular segment relative to the mounting segment. Moreover, the at least one second stabilizing member may stabilize the annular sealing element against vertical loads. Vertical loads may exemplarily occur when the sealing basket being vertically mounted is filled with filling medium from above.

The at least one first stabilizing member and/ or the at least one second stabilizing member may be integrally formed with the annular sealing member. Thus, the at least one first stabilizing member and/ or the at least one second stabilizing member may be protected from the filling medium.

Optionally, the mounting segment comprises at least one guiding element, wherein the annular segment comprises at least one pivoting element, wherein the at least one pivoting element and the at least one guiding element are configured to slidably and/or rotatably engage.

The at least one pivoting element and the at least one guiding element may be configured to allow translatory movements relative to each other in all spatial directions. Thus, a high flexibility of the sealing basket may be achieved. Further, the at least one pivoting element and the at least one guiding element may be configured to allow translatory movements relative to each other in one plane. Said plane may be tangential to a diameter of the mounting segment. Moreover, the at least one pivoting element and the at least one guiding element may be configured to allow one translatory movement relative to each other in one direction. By limiting the translatory movements of the at least one pivoting element and the at least one guiding element relative to each other the stability of the sealing basket may be increased.

The at least one pivoting element and the at least one guiding element may be configured to allow rotary movements relative to each other around all spatial directions. Thus, a high flexibility of the sealing basket may be achieved.

The at least one pivoting element may comprise a groove, a slot, a pin, a screw, a bolt, and/or a rib.

The at least one pivoting element may extend along an outer surface of the annular sealing member, wherein the at least one pivoting element optionally extends substantially in a straight direction, wherein the at least one pivoting element is further optionally attached to the annular sealing member, wherein the at least one pivoting element is even further optionally beam-shaped.

The at least one pivoting element maybe a rod, a bolt and/or a beam. The at least one pivoting element may have a round cross-section, an oval cross-section and/ or an angular cross-section, such as a rectangular cross-section.

The at least one pivoting element and the at least one guiding element may be configured such that a rotary movement of the at least one pivoting element around the direction of extension of the pivoting element is fixed. Thus, the vertical stability of the sealing basket may be increased.

The at least one pivoting element may extend farther than the annular sealing member at the second end portion in a direction opposite to the first end portion, wherein the at least one pivoting element is optionally curved inwardly towards the center axis of the annular segment. Particularly, a tip portion of the at least one pivoting element in proximity to the second end portion maybe curved inwardly towards the center axis of the annular segment.

If the at least one pivoting element is curved inwardly towards the center axis of the annular segment a wider contact surface of the pivoting element on the inner surface of the second tube may be achieved. Thus, the adjustment of the annular segment may be enhanced.

The at least one guiding element may be arranged on an outer diameter of the mounting segment, wherein the at least one guiding element optionally comprises a groove, a slot, a pin, a screw, a bolt, and/or a rib.

Optionally, the mounting segment comprises a plurality of guiding elements, wherein the annular segment comprises a plurality of pivoting elements, wherein at least one of the pivoting elements and at least one of the guiding elements slidably and/or rotatably engage.

The plurality of guiding elements may be equally distributed on a circumference of the mounting element. The plurality of pivoting elements may be equally distributed on a circumference of the annular sealing member. The mounting segment may comprise at least 15, optionally at least 20, further optionally at least 30, and even further at least 40 guiding elements. The annular segment may comprise at least 15, optionally at least 20, further optionally at least 30, and even further at least 40 pivoting elements. Thus, the stability of the connection of the mounting segment to the annular segment may be increased. Optionally, each guiding element of the plurality of guiding elements engages with the at least one pivoting element.

At least one pivoting element of the plurality of pivoting elements and at least one guiding element of the plurality of guiding elements may be fixed to only rotatably engage.

Optionally, two pivoting elements of the plurality of pivoting elements and two guiding elements of the plurality of guiding elements may be fixed to only rotatably engage. Further optionally, these two pivoting elements of the plurality of pivoting elements and these two guiding elements of the plurality of guiding elements may be arranged opposite to each other on a circumference of the annular sealing member. Thereby, the robustness of the sealing basket is enhanced, whereas the level of flexibility is maintained.

The at least one pivoting element of the plurality of pivoting elements and the at least one guiding element of the plurality of guiding elements maybe fixed such that no translatory movements relative to each other are possible.

Further, the at least one pivoting element of the plurality of pivoting elements and the at least one guiding element of the plurality of guiding elements may be fixed such that a rotary movement of the at least one pivoting element around the direction of extension of the pivoting element is fixed. Thus, the vertical stability of the sealing basket may be increased.

Optionally, the annular segment comprises at least one annular frame element, wherein the at least one annular frame element is connected to the at least one pivoting element, wherein optionally the annular frame element at least partially encircles the annular sealing member.

The at least one annular frame element may at least partially encircle the plurality of pivoting elements. Further, the at least one annular frame element may support at least one pivoting element from the outside. Moreover, the at least one annular frame element may comprise two semicircular elements.

The at least one annular frame element may be fixedly connected to the at least one pivoting element. The at least one annular frame element may be connected to at most 2, optionally at most 4, further optionally at most 8, and even further optionally at most 10 pivoting elements. Thus, the flexibility of the annular segment may be enhanced. The at least one annular frame element may be in sliding contact with at least one pivoting element.

The annular segment may comprise a plurality of annular frame elements, wherein the plurality of pivoting elements and the plurality of annular frame elements may form a grid structure, wherein the grid structure optionally surrounds the annular sealing member.

At least two annular frame elements of the plurality of annular frame elements may be arranged coaxially. Optionally, the plurality of annular frame elements is arranged coaxially. Further, each annular frame element of the plurality of annular frame elements may be equally spaced from another annular frame element. The members and elements of the annular segment, such as the at least one first stabilizing member, the at least one second stabilizing member, the annular sealing member, the at least one pivoting element and the at least one annular frame element may be arranged so that at the annular sealing member is sandwiched by at least one of the at least one first stabilizing member and the at least one second stabilizing member on the one hand and the at least one pivoting element and the at least one annular frame element on the other hand, in a radial direction. Further, the at least one first stabilizing member and/ or the at least one second stabilizing member may be arranged on a radially inner side of the annular sealing member and/or the at least one pivoting element and the at least one annular frame element may be arranged on an radially outer side of the annular sealing member.

The mounting segment may comprise two semicircular elements, wherein the two semicircular elements are optionally connected by means of a screw connection, a bolted connection and/ or a welding connection.

The two semicircular elements may be the halves of a hollow cylinder.

The mounting segment may comprise at least one rib, wherein the at least one rib optionally extends substantially parallel to a center axis of the mounting segment at an outer diameter of the mounting segment. Thus, the stability of the mounting segment may be increased.

The mounting segment may comprise an annular clamping member, wherein the annular clamping member is configured to clamp a portion of the annular sealing member against the outside portion of the first tube.

The annular clamping member may clamp the portion of the annular sealing member against the outside portion of the first tube such that a sealing is achieved between the first tube and the annular sealing element. The portion of the annular sealing member may be the first end portion of the annular segment.

The invention further concerns a method for sealing a space between a first tube and a second tube, wherein the first tube at least partially extends within the second tube, wherein the method comprises the following steps: (a) mounting a sealing basket according to any one of claims 1 to 17 on an outside portion of the first tube; and (b) arranging the sealing basket to be in contact with an inner surface of the second tube to seal the space between the first tube and the second tube. The method may further comprise the step: (c) filling the sealing basket with a filling medium so that the filling medium is in contact with the outside portion of the first tube and the inner surface of the second tube above the second end portion of the annular segment.

Arranging the sealing basket may include pivoting an annular segment of the sealing basket relative to a mounting segment of the sealing basket.

The pivoting may include at least one rotational movement and/ or at least sliding movement.

Arranging the sealing basket may include changing the positions of the first tube and/ or the second tube relative to each other. Exemplarily, the first tube with the mounted sealing basket may be moved vertically and/ or laterally within the second tube.

The method may further comprise the steps: (1) drilling a first hole into a ground surface, wherein the first hole has a diameter which corresponds to an outer diameter of the second tube, and placing the second tube at least partially inside the first hole; (2) drilling a second hole into the ground surface within the first hole, wherein the second hole has a diameter which is larger than an outer diameter of the first tube, wherein the second hole has a diameter which is smaller than an inner diameter of the second tube, and placing the first tube at least partially inside the second hole.

The ground surface maybe the seabed. The steps (1) and (2) maybe performed before the steps (a) to (b) or (a) to (c). Moreover, it will be understood by person skilled in the art that the previously mentioned method steps maybe interchanged in a meaningful way.

The invention further concerns a system for sealing a space between a first tube and a second tube, wherein the first tube at least partially extends within the second tube, wherein the system comprises the first tube, the second tube and a sealing basket as described above, wherein a mounting segment of the sealing basket is mounted on an outside portion of the first tube, and wherein an annular segment of the sealing basket is in contact with an inner surface of the second tube to seal the space between the first tube and the second tube.

The first tube and/ or the second tube may be part of a casing. A casing is a series of steel pipes that are run into a drilled oil well to stabilize the well, keep contaminants and water out of the oil stream, and/or prevent oil from leaching into the groundwater.

A casing is installed in layers, in sections of decreasing diameter that are joined together to form casing strings.

Further, the first tube may be an oil-conducting tube of an oil rig. The first tube may have an outer diameter between io cm and 30 cm, optionally between 15 cm and 25 cm, further optionally between 18 cm and 22 cm.

Furthermore, the second tube may be a conductor pipe. The conductor pipe may be a large diameter pipe that is set into the ground surface to provide an initial stable structural foundation for a borehole or oil well. The conductor pipe maybe a first string of casing. Further, the conductor pipe may have the largest diameter casing to be installed in a well. The second tube may have an inner diameter between 20 cm and 45 cm, optionally between 25 cm and 40 cm, further optionally between 30 cm and 35 cm.

4. Short description of the figures

In the following, exemplary embodiments of the invention are described with reference to the figures. The figures show:

Fig. 1 shows an exemplary sealing basket for sealing a space between a first tube and a second tube in a perspective view;

Fig. 2 shows the exemplary sealing basket from Fig. 1 from a side view;

Fig. 3 shows an exemplary method for sealing a space between a first tube and a second tube, and

Fig. 4 shows an exemplary system for sealing a space between a first tube and a second tube.

5. Detailed description of preferred embodiments

In the following, only some possible embodiments of the invention are described in detail. It is to be understood that these exemplary embodiments can be modified in a number of ways and combined with each other whenever compatible and that certain features may be omitted in so far as they appear dispensable.

Fig. 1 shows an exemplary sealing basket 1 for sealing a space 300 between a first tube too and a second tube 200, wherein the first tube too at least partially extends within the second tube 200 (cf. also Fig. 4), wherein the sealing basket 1 comprises: a mounting segment 2 which is configured for being mounted on an outside portion of the first tube 100, and an annular segment 3, having a first end portion 4 and a second end portion 5, wherein the first end portion 4 is connected to the mounting segment 2, so that the annular segment 3 is pivotably with respect to the mounting segment 2, and wherein the second end portion 5 is configured to be in contact with an inner surface of the second tube 200 to seal the space 300 between the first tube 100 and the second tube 200.

The sealing basket 1 as depicted in Figs. 1 and 2 includes an annular sealing member 6 that comprises an elastic material, i.e. rubber. In further embodiments the material may be an elastomer material, a thermoplastic material, a thermoset material, a fiber reinforced composite material and/or a fabric material.

Further, the sealing basket 1 as depicted in Fig. 1 comprises at least one first stabilizing member 7 being attached to an inside surface of the annular sealing member 6, wherein the at least one first stabilizing member 7 has an annular shape and. The first end portion 4 and the second end portion 5 are spaced from each other by a distance X and the first stabilizing member 7 is displaced from the second end portion 6 by at most X/3.

Moreover, the annular segment 3 of the sealing basket 1 as depicted in Fig. 1 comprises at least one second stabilizing member 8 being attached to an inside surface of the annular sealing member 6. The at least one second stabilizing member 8 extends substantially in a straight direction, wherein the second stabilizing element 8 and a center axis of the annular sealing member 6 substantially lie in one plane.

The mounting segment 2 of the sealing basket 1 of Figs. 1 and 2 comprises at least one guiding element 9, wherein the annular segment 3 comprises at least one pivoting element 10, wherein the at least one pivoting element 10 and the at least one guiding element 9 are configured to slidably and rotatably engage. The depicted at least one pivoting element 10 comprises a slot 11. In further embodiments the pivoting element may comprise a groove, a pin, a screw, a bolt, and/ or a rib.

The at least one pivoting element 10 extends along an outer surface of the annular sealing member 6, wherein the at least one pivoting element 10 extends substantially in a straight direction, wherein the at least one pivoting element is attached to the annular sealing member 6, wherein the at least one pivoting element 10 is beam-shaped. As depicted in Figs, i and 2, the at least one pivoting element io extends farther than the annular sealing member 6 at the second end portion 5 in a direction opposite to the first end portion 4, wherein the at least one pivoting element 10 is curved inwardly towards a center axis of the annular segment 3.

In the exemplary embodiment of the sealing basket 1, the at least one guiding element 9 is arranged on an outer diameter of the mounting segment 2, wherein the at least one guiding element 9 comprises a pin 12.

Moreover, as shown in Figs. 1 and 2, the mounting segment 2 comprises a plurality of guiding elements 9, 13, wherein the annular segment 2 comprises a plurality of pivoting elements 10, 14, wherein at least one of the pivoting elements 10 and at least one of the guiding elements 9 slidably and rotatably engage. Moreover, at least one pivoting element 14 of the plurality of pivoting elements and at least one guiding element 13 of the plurality of guiding elements are fixed to only rotatably engage.

The annular segment of the exemplary sealing basket 1, as depicted, comprises at least one annular frame element 20, wherein the at least one annular frame element 20 is connected to the at least one pivoting element 10. The annular frame element fully encircles the annular sealing member 6. The annular segment 3 comprises a plurality of annular frame elements 20, wherein the plurality of pivoting elements 10 and the plurality of annular frame elements 20 form a grid structure, wherein the grid structure surrounds the annular sealing member 6.

The mounting segment 2 of the exemplary sealing basket 1 comprises two semicircular elements 15, wherein the two semicircular elements 15 are connected by means of a screw connection 16. Further, the mounting segment 2 comprises at least one rib 17 extending substantially parallel to a center axis of the mounting segment 2 at an outer diameter of the mounting segment 2.

In further embodiments the mounting segment 2 may comprise an annular clamping member, wherein the annular clamping member may be configured to clamp a portion of the annular sealing member 6 against the outside portion of the first tube too.

Fig. 3 shows an exemplary method 500 for sealing a space 300 between a first tube too and a second tube 200, wherein the first tube too at least partially extends within the second tube 200, wherein the method 500 comprises the following steps: (a) mounting 3000 a sealing basket 1 according to any one of claims 1 to 17 on an outside portion of the first tube too; and (b) arranging 4000 the sealing basket 1 to be in contact with an inner surface of the second tube 200 to seal the space 300 between the first tube and the second tube.

The exemplary method as depicted in Fig. 3 comprises the optional step (c) of filling 5000 the sealing basket 1 with a filling medium so that the filling medium is in contact with the outside portion of the first tube 100 and the inner surface of the second tube 200 above the second end portion 5 of the annular segment 3.

The step of arranging 4000 the sealing basket 1 may include pivoting an annular segment 3 of the sealing basket 1 relative to a mounting segment 2 of the sealing basket 1. Further, arranging 4000 the sealing basket 1 may include changing the positions of the first tube and the second tube relative to each other.

The exemplary method 500 as depicted in Fig. 3 comprises the optional steps: (1) drilling 1000 a first hole into a ground surface, wherein the first hole has a diameter which corresponds to an outer diameter of the second tube 200, and placing the second tube 200 at least partially inside the first hole; and (2) drilling 2000 a second hole into the ground surface within the first hole, wherein the second hole has a diameter which is larger than an outer diameter of the first tube too, wherein the second hole has a diameter which is smaller than an inner diameter of the second tube 200, and placing the first tube too at least partially inside the second hole.

Fig. 4 shows an exemplary system 10000 for sealing a space 300 between a first tube 100 and a second tube 200, wherein the first tube 100 at least partially extends within the second tube 200, wherein the system 10000 comprises the first tube 100, the second tube 200 and a sealing basket 1 as described above, wherein a mounting segment 2 of the sealing basket is mounted on an outside portion of the first tube 100, and wherein an annular segment 3 of the sealing basket is in contact with an inner surface of the second tube 200 to seal the space 300 between the first tube 100 and the second tube 200.

As shown in the system 10000 of Fig. 4, the center axes of the first tube 100 and the second tube 200 are inclined and are offset relative to each other. The annular segment 3 being pivotably with respect to the mounting segment 2 compensates the inclination and the offset between the first tube 100 and the second tube 200. 6. List of reference signs

1 sealing basket

2 mounting segment

3 annular segment

4 first end portion

5 second end portion

6 annular sealing member

7 first stabilizing member

8 second stabilizing member

9 guiding element

10 pivoting element n slot

12 pin

13 guiding element

14 pivoting element

15 semicircular element

16 screw connection

17 rib

20 annular frame element

100 first tube

200 second tube

300 space between first tube and second tube

500 method for sealing a space between a first tube and a second tube

1000 drilling a first hole

2000 drilling a second hole

3000 mounting a sealing basket

4000 arranging the sealing basket

5000 filling sealing basket with a filling medium

IOOOO system for sealing a space between a first tube and a second tube