Conduit crossing apparatus

FIELD OF THE INVENTION

Embodiments of the present invention relate to a conduit crossing apparatus and the installation of such apparatus. In particular, they relate to conduit crossing apparatus for use subsea.

BACKGROUND TO THE INVENTION

Sometimes it is necessary for subsea conduits such as pipelines or cables to cross one another on the seabed. One conduit may cross another conduit such that the two conduits are perpendicular to one another, or at some other angle.

If the conduits are not properly secured at the crossing, abrasion can occur, which may lead to a fault and a potential hazard. In some circumstances, one conduit may need to be thermally and electrically shielded from the other conduit. This might be the case, for example, if one of the conduits includes a high voltage power cable.

BRIEF DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

According to various, but not necessarily all, embodiments of the invention there is provided a method of installing a conduit crossing apparatus subsea, wherein the conduit crossing apparatus comprises at least a first, second and third housing parts, each of the first, second and third housing parts including: a passageway for receiving a portion of a conduit for location subsea; one or more chambers at least partially surrounding the passageway; and one or more apertures arranged to enable matter to enter the one or more chambers; and wherein the method comprises: sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the first housing part by sealing at least one aperture of the one or more apertures of the first housing part, thereby causing at least a portion of the first housing part to have a first rigidity; sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the second housing part by sealing at least one aperture of the one or more apertures of the second housing part, thereby causing at least a portion of the second housing part to have a second rigidity that is less than the first rigidity; locating the first housing part, the second housing part and the third housing part along at least part of the length of a conduit for location subsea, such that the conduit passes through the passageway of the first, second and third housing parts, wherein at least one of the apertures of the third housing part is unsealed to enable seawater to enter at least one chamber of the one or more chambers of the third housing part when the conduit is located subsea; and locating the conduit having the first, second and third housing parts thereon subsea.

The second housing part may be located intermediate the first housing part and the third housing part along the length of the conduit.

The method may comprise sealing at least one of liquid matter or solid matter inside the at least one chamber of the first housing part.

The at least one chamber of the first housing part may be substantially filled with at least one of liquid or solid matter.

According to various, but not necessarily all, embodiments of the invention there is provided a method of installing a conduit crossing apparatus, wherein the conduit crossing apparatus comprises at least a first, second and third housing parts, each of the first, second and third housing parts including: a passageway for receiving a portion of a conduit for location in a body of liquid; one or more chambers at least partially surrounding the passageway; and one or more apertures arranged to enable matter to enter the one or more chambers; and wherein the method comprises: sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the first housing part by sealing at least one aperture of the one or more apertures of the first housing part, thereby causing at least a portion of the first housing part to have a first rigidity; sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the second housing part by sealing at least one aperture of the one or more apertures of the second housing part, thereby causing at least a portion of the second housing part to have a second rigidity that is less than the first rigidity; locating the first housing part, the second housing part and the third housing part along at least part of the length of a conduit for location in a body of liquid, such that the conduit passes through the passageway of the first, second and third housing parts, wherein at least one of the apertures of the third housing part is unsealed to enable liquid to enter at least one chamber of the one or more chambers of the third housing part when the conduit is located in the body of liquid; and locating the conduit having the first, second and third housing parts thereon in the body of liquid.

According to various, but not necessarily all, embodiments of the invention there is provided a subsea conduit crossing apparatus comprising at least first, second and third housing parts, each of the first, second and third housing parts including: a passageway for receiving a portion of a conduit for location subsea; one or more chambers at least partially surrounding the passageway, wherein: gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the first housing part, thereby causing at least a portion of the first housing part to have a first rigidity; gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of a second housing part, thereby causing at least a portion of the second housing part to have a second rigidity that is less than the first rigidity; and the first housing part, the second housing part and a third housing part are located along at least part of the length of a conduit for location subsea, such that the conduit passes through the passageway of the first, second and third housing parts, and at least one chamber of the one or more chambers of the third housing part is unsealed.

According to various, but not necessarily all, embodiments of the invention there is provided a conduit crossing apparatus comprising at least first, second and third housing parts, each of the first, second and third housing parts including: a passageway for receiving a portion of a conduit for location in a body of liquid; one or more chambers at least partially surrounding the passageway, wherein: gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the first housing part, thereby causing at least a portion of the first housing part to have a first rigidity; gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of a second housing part, thereby causing at least a portion of the second housing part to have a second rigidity that is less than the first rigidity; and the first housing part, the second housing part and a third housing part are located along at least part of the length of a conduit for location in a body of liquid, such that the conduit passes through the passageway of the first, second and third housing parts, and at least one chamber of the one or more chambers of the third housing part is unsealed.

According to various, but not necessarily all, embodiments of the invention there is provided a method of installing a conduit crossing apparatus subsea, wherein the conduit crossing apparatus comprises at least one housing part and at least one further housing part, wherein the housing part and the further housing part each include: a passageway for receiving a portion of a conduit for location subsea; one or more chambers at least partially surrounding the passageway; and one or more apertures arranged to enable matter to enter the one or more chambers; and wherein the method comprises: sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the housing part by sealing at least one aperture of the one or more apertures of the housing part; locating the housing part and the further housing part along at least part of the length of a conduit for location subsea, such that the conduit passes through the passageway of the housing part and the further housing part, wherein at least one of the apertures of the further housing part is unsealed to enable seawater to enter at least one chamber of the one or more chambers of the further housing part when the conduit is located subsea; and locating the conduit, having the housing part and the further housing part thereon, subsea.

The method may comprise sealing at least one of liquid matter or solid matter inside the at least one chamber of the housing part.

According to various, but not necessarily all, embodiments of the invention there is provided a method of installing a conduit crossing apparatus, wherein the conduit crossing apparatus comprises at least one housing part and at least one further housing part, wherein the housing part and the further housing part each include: a passageway for receiving a portion of a conduit for location in a body of liquid; one or more chambers at least partially surrounding the passageway; and one or more apertures arranged to enable matter to enter the one or more chambers; and wherein the method comprises: sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the housing part by sealing at least one aperture of the one or more apertures of the housing part; locating the housing part and the further housing part along at least part of the length of a conduit for location in a body of liquid, such that the conduit passes through the passageway of the housing part and the further housing part, wherein at least one of the apertures of the further housing part is unsealed to enable seawater to enter at least one chamber of the one or more chambers of the further housing part when the conduit is located in the body of liquid; and locating the conduit, having the housing part and the further housing part thereon, in the body of liquid.

According to various, but not necessarily all, embodiments of the invention there is provided a subsea conduit crossing apparatus comprising at least a housing part and a further housing part, each of the housing part and the further housing part including: a passageway for receiving a portion of a conduit for location subsea; one or more chambers at least partially surrounding the passageway, wherein: gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the housing part; and the housing part and the further housing part are located along at least part of the length of a subsea conduit, such that the subsea conduit passes through the passageway of the housing part and the further housing part, and at least one chamber of the one or more chambers of the further housing part is unsealed.

According to various, but not necessarily all, embodiments of the invention there is provided a conduit crossing apparatus comprising at least a housing part and a further housing part, each of the housing part and the further housing part including: a passageway for receiving a portion of a conduit for location in a body of liquid; one or more chambers at least partially surrounding the passageway, wherein: gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the housing part; and the housing part and the further housing part are located along at least part of the length of a conduit for location in a body of liquid, such that the conduit passes through the passageway of the housing part and the further housing part, and at least one chamber of the one or more chambers of the further housing part is unsealed.

According to various, but not necessarily all, embodiments of the invention there is provided a method of installing a conduit crossing apparatus subsea, wherein the conduit crossing apparatus comprises at least one housing part and at least one further housing part, wherein the housing part and the further housing part each include: a passageway for receiving a portion of a conduit for location subsea; one or more chambers at least partially surrounding the passageway; and one or more apertures arranged to enable matter to enter the one or more chambers; and wherein the method comprises: sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the housing part by sealing at least one aperture of the one or more apertures of the housing part, thereby causing at least a portion of the housing part to have a first rigidity; sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the further housing part by sealing at least one aperture of the one or more apertures of the further housing part, thereby causing at least a portion of the further housing part to have a second rigidity that is less than the first rigidity; locating the housing part and the further housing part along at least part of the length of a conduit for location subsea, such that the conduit passes through the passageway of the housing part and the further housing part; and locating the conduit, having the housing part and the further housing part thereon, subsea.

The method may comprise sealing at least one of liquid matter or solid matter inside the at least one chamber of the housing part.

According to various, but not necessarily all, embodiments of the invention there is provided a method of installing a conduit crossing apparatus, wherein the conduit crossing apparatus comprises at least one housing part and at least one further housing part, wherein the housing part and the further housing part each include: a passageway for receiving a portion of a conduit for location in a body of liquid; one or more chambers at least partially surrounding the passageway; and one or more apertures arranged to enable matter to enter the one or more chambers; and wherein the method comprises: sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the housing part by sealing at least one aperture of the one or more apertures of the housing part, thereby causing at least a portion of the housing part to have a first rigidity; sealing gaseous, liquid and/or solid matter inside at least one of the one or more chambers of the further housing part by sealing at least one aperture of the one or more apertures of the further housing part, thereby causing at least a portion of the further housing part to have a second rigidity that is less than the first rigidity; locating the housing part and the further housing part along at least part of the length of a conduit for location in a body of liquid, such that the conduit passes through the passageway of the housing part and the further housing part; and locating the conduit, having the housing part and the further housing part thereon, in the body of liquid.

According to various, but not necessarily all, embodiments of the invention there is provided a subsea conduit crossing apparatus comprising at least a housing part and a further housing part, wherein the housing part and the further housing part each include: a passageway for receiving a portion of a conduit for location subsea; one or more chambers at least partially surrounding the passageway, wherein: gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the housing part, thereby causing at least a portion of the housing part to have a first rigidity; gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the further housing part, thereby causing at least a portion of the further housing part to have a second rigidity that is less than the first rigidity; and the housing part and the further housing part are located along at least part of the length of a subsea conduit, such that the subsea conduit passes through the passageway of the housing part and the further housing part.

According to various, but not necessarily all, embodiments of the invention there is provided a conduit crossing apparatus comprising at least a housing part and a further housing part, wherein the housing part and the further housing part each include: a passageway for receiving a portion of a conduit for location in a body of liquid; one or more chambers at least partially surrounding the passageway, wherein: gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the housing part, thereby causing at least a portion of the housing part to have a first rigidity; gaseous, liquid and/or solid matter is sealed inside at least one of the one or more chambers of the further housing part, thereby causing at least a portion of the further housing part to have a second rigidity that is less than the first rigidity; and the housing part and the further housing part are located along at least part of the length of a conduit, such that the conduit passes through the passageway of the housing part and the further housing part. According to various, but not necessarily all, embodiments of the invention there is provided a conduit crossing apparatus for use subsea, the conduit crossing apparatus comprising a plurality of housing parts, each housing part comprising: a passageway for receiving a portion of a subsea conduit; one or more chambers at least partially surrounding the passageway; at least one aperture arranged to enable matter to enter at least one of the one or more chambers; and at least one seal for sealing the at least one aperture.

The passageway may be provided by a through hole in the housing part. Each housing part may comprise an entrance for the conduit and an exit for the conduit. The passageway may extend from the entrance to the exit.

The passageway may comprise an intermediate portion, intermediate the entrance and the exit, having a greater cross-sectional extent than at least one of the entrance or the exit. The intermediate portion may have a greater cross- sectional extent than the entrance and the exit.

The passageway may comprise an entrance portion and an outwardly tapered portion. The cross-sectional extent of the passageway may becomes larger as the outwardly tapered portion extends away from the entrance portion and towards the intermediate portion.

The passageway may comprise an inwardly tapered portion and an exit portion. The cross-sectional extent of the passageway may become smaller as the inwardly tapered portion extends away from the intermediate portion and towards the exit portion.

The entrance may be defined by a first aperture in each housing part and the exit may be defined by a second aperture in each housing part. At least a portion of the passageway may be substantially cylindrical.

Each housing part may have a length defined by a length dimension, a height defined by a height dimension and a width defined by a width dimension, and the length dimension is greater than the height and the width. The passageway may have a length aligned with the length dimension.

The cross-sectional extent of the passageway may be determined in a plane orthogonal to the length of the passageway.

Each housing part may have a lowermost surface and an uppermost surface in use. The lowermost surface may be greater, in the width dimension, than the uppermost surface.

A cross-section of a portion of the housing part, determined in a plane that is orthogonal to the length dimension, may be substantially trapezoidal.

The at least one seal may be configured to provide a fluid-tight seal.

According to various, but not necessarily all, embodiments of the invention there is provided a conduit crossing apparatus for use in a body of liquid, the conduit crossing apparatus comprising a plurality of housing parts, each housing part comprising: a passageway for receiving a portion of a conduit for location in the body of liquid; one or more chambers at least partially surrounding the passageway; at least one aperture arranged to enable matter to enter at least one of the one or more chambers; and at least one seal for sealing the at least one aperture.

According to various, but not necessarily all, embodiments of the invention there is provided a housing part for a subsea conduit crossing apparatus, the housing part comprising: a passageway for receiving a portion of a subsea conduit; one or more chambers at least partially surrounding the passageway; at least one aperture arranged to enable matter to enter at least one of the one or more chambers; and at least one seal for sealing the at least one aperture.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of various examples of embodiments of the present invention reference will now be made by way of example only to the accompanying drawings in which:

FIG. 1 A illustrates a perspective view of a housing subpart;

FIG. 1 B illustrates a side view of the housing subpart;

FIG. 1 C illustrates a rear view of the housing subpart;

FIG. 1 D illustrates a plan view of the housing subpart;

FIG. 1 E illustrates a view through the line G-G marked in FIG. 1 D;

FIG. 2 illustrates a schematic of a conduit in the housing subpart;

FIG. 3 illustrates a seal;

FIG. 4 illustrates a perspective view of a conduit crossing apparatus;

FIG. 5 illustrates an underside view and a side view of the conduit crossing apparatus;

FIG. 6 illustrates an end view of the conduit crossing apparatus;

FIG. 7 illustrates a close-up perspective view of some of the conduit crossing apparatus;

FIG. 8 illustrates an end view of a housing part of the conduit crossing apparatus and a cross-sectional view of a conduit passing through the housing part;

FIG. 9 illustrates a schematic of an alternative example of a housing part; and FIG. 10 illustrates a flow chart of a method.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS OF THE INVENTION

Embodiments of the invention relate to a conduit crossing apparatus for use subsea and methods of installing such an apparatus subsea. As explained above, in some circumstances it may be desirable to route a conduit across another conduit on the seabed. One or both of the conduits could be a pipeline for conveying a hydrocarbon mixture such as crude oil or natural gas. Alternatively or additionally, one or both of the conduits could be or include a telecommunications cable comprising one or more optical fibres for conveying telecommunications signals, and/or an electrical cable such as a high voltage cable for conveying electrical power from a wind turbine, and/or a cable for communicating with a wind turbine or another apparatus. One or both of the conduits could be an umbilical including one or more different types of cable, including those mentioned above.

The conduit crossing apparatus enables a separation between the two conduits to be maintained. Advantageously, this separation potentially eliminates abrasion, reduces electrical interference and/or reduces heat transfer between the subsea conduits.

FIGs 1 A to 1 D illustrate a perspective view, a side view, a rear view and a plan view of an example of a housing subpart 10. FIG 1 E illustrates a view of the housing subpart 10 through the line G-G marked in FIG. 1 D.

The housing subpart 10 is configured to mate with one or more other housing subparts to form a (complete) housing part. In some implementations, the housing subpart 10 may include one or more connectors to connect the housing subpart 10 to another housing subpart. The one or more connectors may be provided by one or more recesses 44 and/or one or more projections 46, as shown in the illustrated housing subpart 10.

In the illustrated example, the housing subpart has inner faces 42. One of the inner faces 42 comprises one or more projections 44. Another of the inner faces 42 comprises one or more recesses 46. The illustrated housing subpart 10 is configured to mate with another housing subpart that is identical to the illustrated housing subpart 10 to form a (complete) housing part. Each of the projections 44 in the illustrated housing subpart 10 extend into the recesses 46 of the other housing subpart, and the projections 44 of the other housing subpart 10 extend into the recesses 46 of the housing subpart 10.

The inner faces 42, projections 44 and recesses 46 of the housing subpart 10 provide an interface 40 between the two housing subparts 10. In the illustrated example, when the two housing subparts 10 mate, the inner faces 42 of the housing subparts 10 abut one another.

It could be that each of the inner faces 42 includes only one projection 44 or one recess 46, multiple projections 44 or multiple recesses 46 or a combination of projections 44 and recesses 46.

The housing subpart 10 comprises a first end portion 11 , an intermediate portion 12 and a second end portion 13. The first end portion 11 , the intermediate portion 12 and the second end portion 13 may be integrally formed. They may, for example, be formed of a plastics material using rotational moulding.

In this example, the first end portion 11 comprises a recess 21 and the second end portion 13 comprises a recess 22. When the housing subpart 10 has been mated with another housing subpart 10, the connection between the two housing subparts 10 may be (further) secured using one or more retainers. A retainer may be located in the recesses 21 formed in the first end portions 11 of the housing subparts 10 and a retainer may be located in the recesses 22 formed in the second end portions 13 of the housing subparts 10. Each retainer may, for instance, be formed from one or more metals (e.g., an alloy) and/or could in the form of a band or a strap.

It will be appreciated by those skilled in the art that more or fewer retainers could be used than those in the illustrated example, which may involve the use of more or fewer recesses 21 , 22, and those recesses 21 , 22 could be located anywhere on the exterior surfaces of the housing subparts 10.

The housing part (formed from multiple housing subparts 10) comprises a passageway 30 for receiving a portion of a subsea conduit. A portion of the passageway 30 (in this example, one half of the passageway 30) is provided by a housing subpart 10 and can be seen in FIGs 1 A to 1 E.

The housing part also comprises an entrance 2 and an exit 8 for the conduit. The entrance 2 is provided by the first end portion 11 and the exit 8 is provided by the second end portion 13. The entrance 2 is formed by a first aperture in the housing part which is defined by the connected housing subparts 10. The exit 8 is formed by a second aperture in the housing part which is defined by the connected housing subparts 10.

The housing part has a length defined by a length dimension, a height defined by a height dimension and a width defined by a height dimension. The length, width and height dimensions are orthogonal. The length may extend from the entrance 2 to the exit 8. The passageway 30 may have a length that is aligned with the length of the housing part and aligned with the length dimension. The cross-sectional extent of the passageway 30 at a particular location along the length may be determined in plane that is orthogonal to the length of the passageway (i.e. , a plane defined in the height and width dimensions).

The passageway 30 extends from the entrance 2 to the exit 8. The passageway 30 is a through hole in the housing part. In the illustrated example, the cross- sectional extent of the passageway 30 varies along its length. The illustrated passageway 30 comprises an entrance portion 32, a second grip portion 33, a first tapered portion 34, an intermediate portion 35, a second tapered portion 36, a second grip portion 37 and an exit portion 38. The passageway 30, and all of its portions 32-38, is defined by the internal surfaces of the housing subparts 10 which form the housing part. The entrance portion 32 is located (immediately) adjacent to the entrance 2. The exit portion 38 is located (immediately) adjacent to the exit 8. In this example, each of the entrance portion 32 and the exit portion 38 is substantially cylindrical in shape.

The intermediate portion 35 is located intermediate the entrance 2 and the exit 8. In this example, the intermediate portion 35 is substantially cylindrical in shape. The intermediate portion 35 of the passageway 30 has a greater cross- sectional extent than both the entrance 2 and the entrance portion 32 of the passageway 30. The intermediate portion 35 of the passageway 30 also has a greater cross-sectional extent than both the exit 8 and the exit portion 38 of the passageway 30.

The first grip portion 33 is located intermediate the intermediate portion 35 and the entrance portion 32. The second grip portion 37 is located intermediate the intermediate portion 35 and the exit portion 38. The grip portions 33, 37 of the illustrated passageway 30 have the narrowest cross-sectional extent of all of the portions 32-38. That is, the grip portions 33, 37 have a narrower cross- sectional extent that the entrance portion 32 and the exit portion 38. In this example, the housing part is configured to grip the conduit at the grip portions 32, 37 of the passageway 30 to hold the housing part in position on the conduit. The cross-sectional extent of the passageway 30 might be very similar to the cross-sectional extent of the conduit that is to be located in the passageway 30.

The first tapered portion 34 of the passageway 30 is located intermediate the intermediate portion 35 and the entrance portion 32, and also intermediate the first grip portion 33 and the intermediate portion 35. The first tapered portion 34 tapers outwardly as the first tapered portion 34 extends away from the entrance portion 32 and the first grip portion 33 and towards the intermediate portion 35, such that the cross-sectional extent of the passageway 30 becomes larger/wider. The second tapered portion 36 of the passageway 30 is located intermediate the intermediate portion 35 and the exit portion 38, and also intermediate the second grip portion 37 and the intermediate portion 35. The second tapered portion 36 tapers inwardly as the second tapered portion 36 extends away from intermediate portion 35 and towards the second grip portion 37 and the exit portion 38, such that the cross-sectional extent of the passageway 30 becomes smaller/narrower.

FIG. 2 illustrates a schematic of a conduit 200 in the housing subpart 10. In this example, the conduit 200 is a flexible conduit. The conduit 200 might not be flexible in other examples. The conduit 200 comprises one or more cables 201 and a cable protection system 210 surrounding the one or more cables.

The conduit 200 enters the passageway 30 of the housing part at the entrance 2 and exits the passageway 30 at the exit 8. The conduit 200 is bending in FIG. 2. It is gripped by housing part at the grip portions 33, 37 of the passageway 30. The wider cross-sectional extent of the passageway 30 at the intermediate portion 35 advantageously provides the conduit 200 with an adequate volume to bend within the housing part.

It will be appreciated by those skilled in the art that a passageway 30 that varies in the manner illustrated and described above might not be necessary if the conduit 200 received in the passageway 30 is not intended to bend within the passageway. This might be the case, for example, if the conduit 200 is not flexible.

The shaping of the tapered portions 34, 36 may cause less friction between the internal surface of the housing part and the conduit 200 (e.g., than if a more abrupt step were present) and improve longevity. The housing part comprises one or more chambers 50 that at least partially surround the passageway 30. The one or more chambers 50 may fully surround the passageway 30 in a plane defined by the height and width dimensions. Where there are multiple chambers 50, each chamber 50 may partially surround the passageway 30 such that the multiple chambers 50 collectively fully surround the passageway 30 in a plane defined by the height and width dimensions.

The one or more chambers 50 may extend along at least part of the length of the housing part and/or at least part of the length of the passageway 30. The one or more chambers 50 may extend along at least a majority of the length of the housing part and/or at least a majority of the length of the passageway 30. The one or more chambers 50 could extend along substantially the entire length of the housing part and/or substantially the entire length of the passageway 30.

Each housing subpart 10 may comprise at least one chamber 50, such that a housing part formed from multiple housing subparts 10 comprises multiple chambers. In the illustrated example, each housing subpart 10 comprises a single chamber that surrounds substantially half of the passageway 30 in a plane defined by the height and width dimensions, and which extends along substantially the entire length of the housing part and substantially the entire length of the passageway 30. It will be appreciated by those skilled in the art, however, that the chambers may be arranged differently in other examples.

The one or more chambers 50 are for storing gaseous, liquid and/or solid matter. For example, the chamber(s) 50 may store gaseous matter in the form of air. The chamber(s) 50 may store liquid matter in the form of water, such as seawater. The chamber(s) 50 may store solid matter such as sand and/or a metal (e.g., iron ore in the form of iron filings).

In some examples, one, some or all of the chambers 50 of a housing part might store a single one of gaseous matter, liquid matter and solid matter. In other examples, one or each chamber 50 might store a combination of gaseous matter, liquid matter and solid matter. Examples include part filling a chamber 50 with liquid or solid matter, and leaving the chamber 50 part full of gaseous matter such as air. In other examples, a chamber could be substantially filled with gaseous matter, liquid matter or solid matter. Different chambers in a housing part may be filled differently (e.g., they may store different combinations of matter types from each other).

A housing part may include at least one aperture 48 that is arranged to enable matter to enter at least one of the chambers 50. In some examples, such as that illustrated, each housing subpart 10 may include at least one aperture 48 that is arranged to enable matter to enter at least one of the chambers 50. Where a housing part or subpart 10 includes multiple chambers 50, it may include at least one aperture 48 per chamber 50.

The housing part or subpart 10 may comprise at least one seal 60 for sealing at least one aperture 48. FIG. 3 provides an example of such a seal 60. The seal 60 illustrated in FIG. 3 is a threaded seal that is configured to engage with a threaded aperture, but in other examples neither the seal 60 nor the aperture need be threaded. Any type of seal could be used. The seal 60 may be configured to provide a fluid-tight seal. Such a fluid-tight seal may prevent liquid (e.g., seawater) from entering a chamber 50 through an aperture after a housing part has been submerged in that liquid.

The apertures 48 are located on the inner faces 42 of the housing subpart in the illustrated example, but they could be located elsewhere in other examples. An advantage of locating the apertures 48 and the seals 60 on an internal surface of the housing part (such as the inner faces 42) rather than an external surface is that they are less likely to be damaged by external elements.

FIGs 4, 5 and 6 illustrate perspective, underside 501 , side 502 and end 503 views of a conduit crossing apparatus 1000. The conduit crossing apparatus 1000 comprises multiple housing parts 101 -103. Each of the housing parts 101 - 103 is formed from the housing subparts 10 described above and illustrated in FIGs 1 A to 3. A conduit 200 (comprising a cable protection system 210) is shown in FIGs 4, 5 and 6 extending through the passageway 30 of each of the housing parts 101 -103. The housing parts 101 -103 are located along at least part of the length of the conduit 200.

The rigidity of at least a portion of a housing part 101 -103 depends on the matter that is stored in a chamber 50 and, in at least some circumstances, whether the chamber 50 is sealed. For example, a chamber 50 that stores solid matter (e.g., sand or iron filings) is more rigid than a chamber that stores liquid matter (e.g., seawater). A chamber 50 that stores liquid or solid matter is more rigid than a sealed chamber 50 that stores gaseous matter such as air. A sealed chamber 50 that stores air is more rigid than an unsealed chamber 50 with air therein.

The conduit crossing apparatus 1000 may include at least a first housing part 101 , at least a second housing part 102 and at least a third housing part 103.

Gaseous, liquid and/or solid matter may be sealed inside at least one of the one or more chambers 50 of the first housing part 101 (by sealing at least one aperture 48 of the one or more apertures 48 of the first housing part 101 ), thereby causing at least a portion of the first housing part to have a first rigidity.

Gaseous, liquid and/or solid matter may be sealed inside at least one of the one or more chambers 50 of the second housing part 102 by sealing at least one aperture 48 of the one or more apertures 48 of the second housing part 102, thereby causing at least a portion of the second housing part 102 to have a second rigidity that is less than the first rigidity.

For example, solid matter (e.g., sand or iron filings) could be sealed inside at least one of chambers 50 of the first housing part 101 and liquid matter (e.g., seawater) could be sealed inside at least one of the chambers 50 of the second housing part 102. This would provide the first housing part 101 with a greater rigidity than the second housing part 102.

Alternatively, liquid matter (e.g., seawater) could be sealed inside at least one of the chambers 50 of the first housing part 101 and gaseous matter (e.g., air) could be sealed inside at least one of the chambers 50 of the second housing part 102. This would provide the first housing part 101 with a greater rigidity than the second housing part 102.

Alternatively, gaseous matter (e.g., air) could be sealed inside at least one of the chambers 50 of the first housing part 101 at a first pressure and gaseous matter (e.g., air) could be sealed inside at least one of the chambers 50 of the second housing part 102 at a second pressure, where the first pressure is greater than the second pressure. This would provide the first housing part 101 with a greater rigidity than the second housing part 102.

Alternatively, solid matter (e.g., sand or iron filings) could be sealed inside at least one of chambers 50 of the first housing part 101 and gaseous matter (e.g., air) could be sealed inside at least one of the chambers 50 of the second housing part 102. This would provide the first housing part 101 with a greater rigidity than the second housing part 102.

Alternatively, liquid matter (e.g., seawater) could be sealed inside at least one of chambers 50 of the first housing part 101 and gaseous matter (e.g., air) could be sealed inside at least one of the chambers 50 of the second housing part 102. This would provide the first housing part 101 with a greater rigidity than the second housing part 102.

At least one of the one aperture 48 of the one or more apertures 48 of the third housing part 103 may be left unsealed. This may enable seawater to enter at least one chamber 50 of the third housing part 103 when the third housing part 103 is submerged in seawater. This will provide the third housing part 103 with a third rigidity that is less than the first and second rigidities - i.e., the third housing part 103 will be less rigid than the first and second housing parts 101 , 102. In these circumstances, the third housing part 103 may be compressible and the first and second housing parts 101 , 102 may be substantially incompressible.

The second housing part 102 may be located intermediate the first housing part 101 and the third housing part 103 along the length of the conduit 200, as illustrated in FIGs 4, 5 and 6.

Furthermore, in the example illustrated in FIGs 4, 5 and 6, the conduit crossing apparatus 1000 includes multiple first housing parts 101 , multiple second housing parts 102 and multiple third housing parts 103, although this need not be the case in every example.

At least one first housing part 101 might be located intermediate two second housing parts 102 along the length of the conduit, as shown in FIGs 4 and 5. At least one first housing part 101 might be located intermediate two third housing parts 103 along the length of the conduit, as shown in FIGs 4 and 5. At least one second housing part 102 might be located intermediate a first housing part 101 and a third housing part 103 along the length of the conduit, as shown in FIGs 4 and 5.

In the example illustrated in FIGs 4, 5 and 6, the location at which the conduit 200 crosses another conduit above or below it might be where the at least one first housing 101 is positioned. The first housing part 101 is more rigid (and less compressible) than the second and third housing parts 102, 103, and is therefore able to provide an appropriate spacing between the conduit 200 passing through the first housing 101 and the other conduit above or below it.

The second housing parts 102 are less rigid than the first housing parts 102, but are not located as close to the crossing point of the conduits as the first housing parts 102 and therefore do not need to space the conduit 200 as far from the other conduit. The third housing parts 103 are less rigid than the second housing parts 102 but are not located as close to the crossing point of the conduits as the second housing parts 102 and therefore and therefore do not need to space the conduit 200 as far from the other conduit.

As explained above, spacing the conduits at the crossing point of the conduit may potentially eliminate abrasion, reduce electrical interference and/or reduce heat transfer between the conduits.

An advantage of having housing parts 101 -103 of differing rigidities as described above is that time and/or material cost may be reduced. For example, if the first housing parts 101 are filled with iron filings and the second housing parts 102 are filled with seawater, the cost of filing the second housing parts 102 may be lower than if they were filled with iron filings. If the third housing parts are unsealed and not filled with liquid or solid matter prior to submerging the apparatus 1000 in seawater, time and/or materials is/are saved relative to if they were filled with solid and/or liquid matter.

FIG. 7 illustrates a close-up perspective view of some of the conduit crossing apparatus 1000. In FIG. 7, the uppermost surface of the housing parts 101 is labelled with the reference numeral 62. Retainers 150 can be seen located in the recesses 21 , 22 in the exterior of the housing parts 101 , retaining the housing subparts 10 together.

A cross-section of the conduit 200 and the cable protection system 210 can be seen in FIG. 7. Multiple cables 201 -203 are located inside the cable protection system 210. In this example, a metallic return (MR) cable 201 and power transmission (high voltage direct current; HVDC) cables 202, 203 are present. In the illustrated example, the cable protection system 210 includes a cable housing 220, spacers 240, 245 for spacing the cables 201-203 from the cable housing 220 and retainers 240 for holding the cable housing 220 together.

FIG. 8 illustrates an end view of a housing part 101/102/103 of the conduit crossing apparatus 1000 and a cross-sectional view of the conduit 200 passing through the housing part 101/102/103. The lowermost surface of the housing part has been labelled with the reference numeral 64 in FIG. 8. FIG. 8 reveals that a fibre optic cable 204 is also present in the conduit 200, in addition to the MR and HVDC cables 201 -203.

The housing parts 101-103 are substantially shaped as rectangular prisms or cubes. This need not be the case in every example though. FIG. 9 illustrates a schematic of an alternative example of a housing part 100a that is substantially shaped as a trapezoidal prism. Other shapes are possible, including ovoidal.

In the example illustrated in FIG. 9, the housing part 100a is formed of housing subparts 10a, 10b which have an interface 140. The housing part 164 is wider at its lowermost surface 164 than its uppermost surface 62. This may help with stability when the lowermost surface 164 is supported by another surface. It may, for example, mean that is greater torque is required to rotate the housing part 164 away from its desired position subsea.

The housing part 100a may have a lower drag factor due to its shape, which can improve stability. Its shape may also mean that it is less likely to be snagged with anchors and/or fishing gear.

FIG. 10 illustrates a flow chart of a method of installing the conduit crossing apparatus 1000 subsea when a conduit 200 is installed subsea. The installer may begin with a plurality of housing subparts 10, where the chambers 50 of the housing subparts 10 are empty and the apertures 48 are unsealed. The installer is then free to fill the chambers 50 with matter in a manner that is appropriate to the job at hand, and to locate housing subparts 10 onto the conduit 200 being installed in a manner that is appropriate to the job at hand.

In block 1002 in FIG. 10, the installer may seal gaseous, liquid and/or solid matter inside at least one of the one or more chambers 50 of at least a first housing part 101 by sealing at least one aperture 48 of the one or more apertures 48 of the first housing part 101 , thereby causing at least a portion of the first housing part 101 to have a first rigidity. The installer may also seal gaseous, liquid and/or solid matter inside at least one of the one or more chambers 50 of at least a second housing part 102 by sealing at least one aperture 48 of the one or more apertures 48 of the second housing part 102, thereby causing at least a portion of the second housing part 102 to have a second rigidity that is less than the first rigidity. Expressed differently, at least a portion of the first housing part 101 may have a first compressibility and at least a portion of the second housing part 102 may have a second compressibility, wherein the second compressibility is greater than the first compressibility.

In block 1004 in FIG. 10, the installer may locate the first housing part 101 , the second housing part 102 and at least a third housing part 103 along at least part of the length of the conduit 200, such that the conduit 200 passes through the passageway of the first, second and third housing parts 101-103. At least one of the apertures 48 of the third housing part 103 may be unsealed to enable seawater to enter at least one chamber 50 of the one or more chambers of the third housing part 103 when the conduit 200 is located subsea. This may provide at least a portion of third housing part 103 with a third rigidity and a third compressibility, where the third rigidity is less than the second rigidity (of at least a portion of the second housing part 102) and the third compressibility is greater than the second compressibility (of at least a portion of the second housing part 102).

In some examples, the conduit crossing apparatus 1000 on the conduit 200 may be the same as that described above and illustrated in the FIGs. In other examples, depending on the implementation, (i) one, some or all of the first housing parts 101 , (ii) one some or all of the second housing parts 102 or (iii) one, some or all of the third housing parts 103 might not be present in the conduit crossing apparatus 1000.

In this example, in block 1006 in FIG. 10, the conduit 200 having the first, second and third housing parts 101 -103 is located subsea. This may involve positioning at least a portion of the conduit crossing apparatus 1000 over an existing subsea conduit. For example, the one or more of the first housing parts 101 may be located on or above an existing subsea conduit. The crossing point may then be fixed in position by laying rocks over the conduit crossing apparatus 1000 at the location of the crossing point. Advantageously, the housing parts 101-103 may protect the conduit 200 when the rocks are laid, with the degree of protection being dependent on how the chambers 50 of the housing parts 101 -103 are filled and their consequent rigidity/compressibility.

Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed. For example, while reference is made below to subsea crossings, it will be appreciated by those skilled in the art that embodiments of the invention can also be implemented in other bodies of liquid or water, such as rivers or lakes.

In the examples provided above, the housing parts 101-103, 100a of the apparatus 1000 are separate housings. They could be interconnected together. In some implementations, the housing parts 101 -103, 100a of the apparatus 1000 could be parts of a single, larger housing. For example, the housing parts 101 -103, 100a in an apparatus 1000 may be integrally formed in a single larger housing. The crossing apparatus 1000 could be installed on a conduit 200 in anticipation that another conduit will be cross it in future. In such circumstances, the housing parts 101 -103, 100a may space the conduit 200 passing through them from a conduit that is located above at least some of the housing parts 101 -103, 100a rather than below them.

Features described in the preceding description may be used in combinations other than the combinations explicitly described.

Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon. l/we claim: