Method for placing an oil pipeline on the seafloor and monitoring the surrounding areas of the pipeline for approaching ships and warning ships considered capable of causing damage to the pipeline

Description

/ 17 METHOD FOR PLACING AN OIL PIPELINE ON THE SEAFLOOR AND MONITORING THE SURROUNDING AREAS OF THE PIPELINE FOR APPROACHING SHIPS AND WARNING SHIPS CONSIDERED CAPABLE OF CAUSING DAMAGE TO THE PIPELINE Field of invention

[001] The present invention relates to the field of laying and protecting submarine pipelines. Background of the invention

[002] Submarine pipelines laid on the seabed generally require some type of protection to minimize the chances of damage if they are subject to interaction with trawling gear from fishing vessels and / or vessel anchor(s). This is particularly important in relatively shallow waters, such as water depths of up to 1,000 meters.

[003] Subsea pipelines can be a rigid pipe, a flexible pipe, a cable, or an umbilical, or combinations thereof. Rigid and flexible pipes are used to transport fluids such as oil, gas, water, condensate, and any combination thereof to a surface installation, such as a floating vessel or an onshore installation, or between offshore installations. Umbilicals are used to transport combinations of hydraulic fluids, electrical power, gas, and / or chemicals from a surface installation to a subsea structure, or between offshore structures, or even between subsea structures. The subsea structure may be a satellite well, a well cluster, a manifold, a processing unit, or another subsea unit. The surface installation may be an FPSO (Floating Production Storage and Offloading) or another floating installation. Petition 870260060096, dated 06 / 19 / 2026, page 11 / 30 / 17

[004] There is therefore a need to protect the subsea pipeline to maintain its integrity throughout its service life. To protect subsea infrastructure (including structures, pipelines, cables and umbilicals and other subsea assets) against potential damage caused by trawling gear or other vessel-related activities, the current routine method is to provide physical protection to the infrastructure by means of rock covers or berms or to put the infrastructure out of harm’s way by means of dredging or trenching.

[005] Examples of prior art methods for protecting submarine pipelines by means of a protective or mechanical covering are disclosed in US5193937A, WO2017 / 070289A1 and WO02 / 02979.

[006] US5193937A describes a concrete or similar mattress to be placed over a pipeline on the seabed. The mattress comprises an elongated recess or tunnel having an insulating material located therein. The mattress is placed over a submarine pipeline so that the pipeline is received within the tunnel containing insulation. The pipeline is thus physically protected and thermally insulated. The mattress may comprise a plurality of concrete or similar elements articulated together.

[007] WO2017 / 070289A1 refers to a pipe securing mattress for subsea pipelines. The document discusses solutions to issues related to pipelines transporting oil and gas, which may “walk” on the seabed. These pipelines can extend over long distances. During production, these pipelines may tend to move or “walk” due to thermal expansion and contraction of the pipelines, resulting in potential damage to connections, etc.

[008] WO02 / 02979 refers to a method for stabilizing an elongated underwater structure placed on an underwater surface, Petition 870260060096, dated 06 / 19 / 2026, p. 12 / 30 / 17 placing a covering of a water-curable material, such as a cementitious material, over and along the aforementioned elongated structure.

[009] However, there are disadvantages related to the above prior art solutions, because all the above methods are expensive, time-consuming, require large quantities of protective material for some methods, which requires quarries on land, and require dedicated vessels to place or position the physical protection frequently along the entire length of the subsea pipeline. The physical protection placed on the seabed can damage the seabed. In addition, the prior art solutions also require physical protection vessels to be present around the pipeline during the period from when the pipeline is positioned on the seabed until it is fully protected. Furthermore, the vessel(s) used in carrying out these operations emit pollution, causing environmental impact.

[010] Several systems are already known for monitoring vessel traffic at sea. One such system is described in US20130041523A3, which refers to a method for preventing damage to underwater assets by conducting a survey of vessels operating above underwater assets.

[011] One of the objectives of this invention is to provide a cheaper alternative solution for laying and protecting submarine pipelines or parts of submarine pipelines, simplifying submarine operation.

[012] In particular, one of the objectives of the invention is to reduce the amount of mechanical or physical protection needed to protect a submarine pipeline.

[013] Another objective is to reduce the amount of trenching or dredging of the seabed before laying submarine pipelines, in order to protect the submarine pipeline. Petition 870260060096, dated 06 / 19 / 2026, page 13 / 30 / 17

[014] A third objective is to provide a method that avoids the use of physical protection vessels during the placement and protection of a pipeline. Summary of the invention

[015] The invention is presented in the independent claims, while the dependent claims describe other features of the invention.

[016] The invention relates to a method for installing a pipeline. The method reduces the amount of physical and mechanical protection systems required around the pipeline, replacing the part related to protecting the underwater installation work with a digital solution in which approaching vessels can be monitored while navigating near or towards an exposed underwater pipeline, and it is possible to communicate with the approaching vessel to avoid damage to the underwater pipeline.

[017] A method is described for laying a pipeline on the seabed, wherein the method comprises protecting the pipeline with at least two types of protection and wherein the method comprises the steps of: - To bring the oil pipeline to an offshore location using a vessel, - to lay the oil pipeline on the seabed using the vessel, - define a first zone encompassing at least the first part of the pipeline length when laid underwater, where the first part of the length is uncovered, - covering at least a second portion of the pipeline length when laid underwater with a means of physical protection, Petition 870260060096, dated 06 / 19 / 2026, page 14 / 30 / 17 - defining a second zone that extends from the first zone, - Monitor the second zone for vessels approaching the first zone. - to analyze the vessels detected during the aforementioned monitoring of the second zone, in order to determine if the vessels could cause damage to the first part of the pipeline length, - For each vessel monitored in the second zone and deemed capable of causing damage to the first section of the pipeline, informing the vessel about the first zone and / or requesting that the vessel not enter the first zone.

[018] The first zone can be defined as a vertical projection of the pipeline onto the water surface. Alternatively, the first zone can be defined as the vertical projection of the pipeline onto the water surface including an extension in all directions around the vertical projection. This extension can vary from a few meters to thousands of meters and can serve as a safety zone.

[019] If the vessel considered capable of causing damage to the first part of the pipeline is a fishing vessel, the step of informing the vessel about the first zone may include information about the depth of the pipeline and that the vessel must raise the trawl above the depth of the pipeline.

[020] The aforementioned second zone may surround the first zone. The second zone preferably includes the first zone.

[021] The term uncovered in relation to a portion of the pipeline length should, in this context, be understood as a section of the pipeline that is neither buried, nor positioned in a trench, nor covered with protection. Petition 870260060096, dated 06 / 19 / 2026, page 15 / 30 / 17 physics etc., as is the case in the solutions of the prior art discussed above. In other words, an uncovered part of the pipeline resting on the seabed.

[022] Physical protection means can provide either physical or mechanical protection. The laid pipeline can thus have at least two types of protection. In this respect, the first part of the pipeline length and the second part of the pipeline length can be protected according to the method above. The second part of the pipeline length can be covered, for example, with rock dump or a part of the pipeline in the vicinity of a subsea or offshore structure can be covered by conventional protective covers for towing / launching objects.

[023] The aforementioned covering stage may include covering the aforementioned second part of the pipeline length with stones.

[024] The aforementioned length of the second part of the pipeline may be placed in or near an offshore installation and / or close to the coast.

[025] Submarine piping can be fluid piping.

[026] Submarine piping can be a cable, like an electrical cable.

[027] Submarine piping can be a combination of a fluid pipeline and a cable.

[028] The method may involve laying the pipeline between an offshore installation and a satellite well.

[029] The method may involve laying the pipeline between an offshore installation and the coast.

[030] The method may involve laying the pipeline between one offshore installation and another offshore installation. Petition 870260060096, dated 06 / 19 / 2026, page 16 / 30 / 17

[031] The second zone may extend for a sufficient distance of nautical miles from a vertical projection of the pipeline onto the water surface.

[032] Examples of possible components and means to perform the different steps of the method described above are described below.

[033] Define the area that requires protection against fishing and other vessel activities: First zone

[034] Define the extended area, which allows the identification of potential vessels approaching the first zone: Second zone

[035] Use satellite(s) and / or other tools to monitor activities in the second zone and identify potential vessel(s) approaching the first zone based on the data.

[036] Base stations have AIS coverage (Identification System (Automatic) near real-time and near-perfect resolution, meaning latency can be seconds and, at most, minutes. Furthermore, some base stations are located in offshore installations in the North Sea, increasing the possibility of AIS surveillance. These base stations are both government and privately owned. AIS is an automatic tracking system that uses transponders on ships and is used by vessel traffic services (VTS). When satellites are used to detect AIS signatures, the term Satellite-AIS (S-AIS) is used. AIS information complements maritime radar, which remains the primary method of collision avoidance for waterborne transport.

[037] Vessels outside coastal areas, i.e., at a sufficient distance from the coast, are expected to carry AIS, meaning there should be a very small number of vessels without AIS and other types of communication and navigation equipment. Due to uncertainties with the Petition 870260060096, dated 06 / 19 / 2026, page 17 / 30 / 17 composition of vessels in coastal areas, alternative solutions should be limited to non-coastal areas.

[038] For surveillance, the data from the Identification System Automatic navigational aids (AIS) can be monitored via satellites, and the use of AIS Aids to Navigation (ATONs) is employed. AIS transceivers can be equipped with a floating or fixed unit, for example, a navigational aid such as a buoy. Through the use of so-called virtual ATONs, i.e., ATONs that appear on the maps of nearby vessels but are not physical units, the field can be marked on the maps of Electronic Chart Displays (ECDIS) of approaching vessels.

[039] AIS transmission provides the position and purpose of an aid, such as a port or starboard side buoy, even before it is physically close enough to be visible from a ship's bridge.

[040] AIS monitoring will allow observation of large areas and automatic alarms if a vessel approaches the unprotected asset(s). In addition, if a vessel approaches the first zone, the AIS ATONs can transmit virtual markers, which appear on the ECDIS of the passing vessel, marking the unprotected asset. This can provide greater situational awareness for passing vessels, with assets clearly marked for vessels to navigate.

[041] As traffic in coastal areas includes a variety of vessels with limited onboard equipment requirements, this solution is suitable for fields more than 30 nautical miles offshore or from the coast. For fields less than 30 nautical miles offshore, traditional solutions are more suitable as vessels carrying AIS or any communication equipment cannot be relied upon. Petition 870260060096, dated 06 / 19 / 2026, p. 18 / 30 / 17

[042] Using different tools, communicate with approaching fleet that is in the monitoring zone to prevent passage and damage to underwater infrastructure.

[043] This may include, more specifically, a solution comprising a combination of the following: - Satellite telephone: An approaching vessel, monitored by AIS, is contacted by satellite telephone. If the satellite telephone number is not available, the nearest available vessel (whose satellite number is known) is contacted by satellite telephone by a supervisor on land. - Using the Global Maritime and Distress Safety System (GMDSS) station of other vessels: A radio operator on board a vessel receives the name, Maritime Mobile Service Identity (MMSI), and call sign number of the approaching vessel from the supervisor ashore. The approaching vessel is then contacted by medium-frequency digital selective calling (MF DSC) or by very high frequency (VHF) if within range. - AIS ATON with AIS message: The approaching vessel receives an AIS alert message and can observe the ATON (both the real and virtual ATON) through its ECDIS and, if close enough, can observe the real ATON by sight and radar.

[044] For surveillance, the combination of monitoring a large area with AIS and continuous surveillance, observation with AIS is considered better than the current solution of the submarine intervention process.

[045] If there is base station coverage in the protection area, these are preferentially used for communication.

[046] Because several fields are outside the base station's coverage, one or more actual AIS ATONs, for example, a mast buoy Petition 870260060096, dated 06 / 19 / 2026, page 19 / 30 / 17 placed in the field, with several virtual AIS ATONs marking the pipeline on the seabed, could be used. Such a buoy would be the size of a typical navigation marker. This buoy could also be equipped with a radar reflector, marking it for vessels that for some reason have turned off their AIS transponder. Furthermore, with position messages being transmitted, warships could also receive information about the ongoing operation, even if their AIS is only operating in receive mode and not transmit mode.

[047] An AIS transceiver located about five meters above sea level would typically have a range of approximately 10 kilometers on average. If a restriction that no point on the submarine pipeline is included, measured vertically from the surface, is at least six kilometers within the AIS coverage, an actual AIS ATON would be needed approximately every 14 kilometers. This would give at least 10 minutes for a ship / vessel traveling at 20 knots to be notified of the ATONs and 20 minutes for a ship / vessel traveling at 10 knots, and 40 minutes for a ship / vessel traveling at 5 knots, i.e., enough time to make a navigation maneuver to avoid the area around the pipeline in the first zone.

[048] Multiple virtual ATONs can be placed anywhere within this AIS coverage area of ​​the real ATONs.

[049] In summary, the invention described herein may have at least some of the following main benefits or advantages compared with prior art solutions: Damage to the seabed and marine environment due to underwater intervention through trenching, dredging, or dumping of rocks on the seabed will be eliminated. Petition 870260060096, dated 06 / 19 / 2026, page 20 / 30 / 17 - Reducing direct pollution and the carbon footprint of a typical subsea installation project. - Reduced health and safety risks for people involved in the subsea project. Fewer people need to work offshore. - Reducing the CAPEX required for the installation of subsea projects; increasing the timeline to reach first oil for a typical subsea oil and gas project. - Reduced complexity and timeline: The solution will be less complex due to the smaller scope during the subsea installation period and the shorter design time compared to a typical subsea oil and gas project.

[050] These and other embodiments of the present invention will be evident from the accompanying drawings, where: Brief description of the drawings

[051] Fig. 1A is a side view of a vessel laying a submarine pipeline on the seabed.

[052] Fig. 1B is a top view of a pipeline on the seabed, where the first part of the pipeline's length corresponds to a first zone and where a second zone extends from the first zone.

[053] Fig. 1C is a top view of a first partial length discovered of a duct on the seabed, where six real AIS ATONs are arranged along the length of the first part of a duct and virtual AIS ATONs between the real AIS ATONs, where the circles indicate a coverage area of ​​the real AIS ATONs whose coverage area represents the second zone. Petition 870260060096, dated 06 / 19 / 2026, p. 21 / 30 / 17

[054] Fig. 2A is a top view of a submarine pipeline extending from a submarine location to a position on land, where the pipeline is divided into a first uncovered length of the pipeline protected by AIS ATONs and virtual AIS ATONs in a section of the pipeline further from the coast and a second covered section of the pipeline length closer to the coast, where the covering is formed by rocks.

[055] Fig. 2B is a top view of a submarine pipeline extending from a submarine location to a submarine facility, where the pipeline is divided into a first uncovered part of the pipeline further from the submarine facility and a covered part along the length of the second part of the pipeline closer to the submarine facility, where the covering is formed by a protective structure.

[056] Fig. 2C is a top view of a submarine pipeline extending between two offshore installations, where the pipeline is divided into an uncovered first part of the pipeline between two covered parts of the pipeline closer to the offshore installations, where the covers are formed by a protective structure.

[057] Fig. 3 shows a sequence of laying a pipeline on the seabed according to the present invention. Detailed description of a preferred form of modality

[058] The embodiments of the invention will be discussed in more detail below with reference to the accompanying drawings. It should be understood, however, that the drawings are not intended to limit the invention to the subject matter represented in the drawings.

[059] Fig. 1A is a side view of a vessel 3 laying a submersible pipeline 1 on the seabed 2. The vessel 3 moves over a water surface 4. The container 3 can be any container Petition 870260060096, dated 06 / 19 / 2026, p. 22 / 30 / 17 for the placement of pipes. These containers 3 for the placement of pipes are known to the expert and will not be described in more detail here.

[060] Fig. 1B is a top view of a pipeline 1 on the seabed. Pipeline 1 is divided into a first part of the pipeline length 1' and a second part of the pipeline length 1''. The first part of the pipeline length 1' corresponds to a first zone 10. That is, the first zone is the vertical projection of the first part of the pipeline length 1' onto the water surface. The first part of the pipeline length 1' is at a depth where protection is necessary to prevent trawl nets and / or vessel anchors that could damage the pipeline. However, the first part of the pipeline length 1' is uncovered and is quite protected by vessel monitoring entering a second zone, which second zone 20 extends from the first zone 10. In the example of Fig. 1B, the second zone 20 includes the first zone 10.The second zone 20 is monitored for vessels approaching the first zone 10. Vessels detected during said monitoring of the second zone 20 are analyzed to determine if the vessels could cause damage to the first partial length of the pipeline 1'. Each vessel monitored in the second zone 20 and considered capable of causing damage to the first part of the pipeline length 1' is informed about the first zone 1' and / or the vessel is requested not to enter the first zone 1'.

[061] Fig. 1C is a top view of a first exposed portion of a 1' pipe on the seabed. This first partial length of the 1' pipe is similar to the first portion of the 1' pipe in Fig. 1B at a depth where protection is needed to avoid trawl nets and / or vessel anchors that could damage the pipe. In the example in Fig. 1C, are Petition 870260060096, dated 06 / 19 / 2026, page 23 / 30 / 17 six real AIS ATONs 30 are placed along the length of the first part of a pipe 1' and virtual AIS ATONs 31 are placed between the real AIS ATONs 30. The circles indicate a coverage area of ​​the real AIS ATONs 30, whose coverage area represents the second monitored zone 20.

[062] The real AIS ATONS 30 can be positioned on a mast buoy placed in the field, with several virtual AIS ATONS 31s marking the first part of the 1' pipe length on the seabed. Such a buoy would be the size of a typical navigation marker. This buoy can also be fitted with a radar reflector, marking it for vessels that for some reason have switched off their AIS transponder. In addition, with position messages being transmitted, warships can also receive information about the ongoing operation, even if their AIS is only activated in receive mode and not in transmit mode.

[063] Fig. 2A is a top view of a submarine pipeline 1 extending from a submarine location to a position on the coast 40. The pipeline 1 is divided into a first uncovered part of the length of the pipeline 1' virtually protected by real AIS ATONs 30 and virtual AIS ATONs 31 in a part of the pipeline 1 furthest from the coast 40 and a second covered part of the length of the pipeline 1'' closer to the coast 40. The covering is formed by rocks 5.

[064] Fig. 2B is a top view of a subsea pipeline 1 extending from a subsea location to a subsea installation 50. The pipeline 1 is divided into a first uncovered section of pipeline length 1' at a point furthest from the subsea installation 50 and a second covered section of pipeline length 1'' closer to the subsea installation 50. The covering is formed by a protective structure 6. Petition 870260060096, dated 06 / 19 / 2026, page 24 / 30 / 17

[065] Fig. 2C is a top view of a submarine pipeline 1 extending between two offshore installations 60. The pipeline 1 is divided into a first section of pipeline length 1', a second section of pipeline length 1'' and a third section of pipeline length 1'''. The second and third sections of pipeline length are closer to the offshore installations 60 and are both covered by a protective structure 6. The first section of pipeline length 1', which is located between the second and third sections of pipeline length 1'', is uncovered.

[066] Fig. 3 shows a possible sequence of a method for laying a pipeline on the seabed according to the present invention (reference 100), defined by the steps of: 100 - Bringing the oil pipeline to an offshore location using a vessel, 101 - to place the oil pipeline on the seabed using the vessel, 102 - define a first zone encompassing at least the first part of the pipeline length when laid underwater, where the first part of the length is uncovered, 103 - defining a second zone that extends from the first zone, 104 - monitor the second zone for vessels approaching the first zone, 105 - Analyze the vessels detected during the aforementioned monitoring of the second zone, in order to determine if the vessels may cause damage to the first part of the pipeline length. Petition 870260060096, dated 06 / 19 / 2026, page 25 / 30 / 17 106 - for each vessel monitored in the second zone and considered capable of causing damage to the first section of the pipeline, informing the vessel about the first zone and / or requesting that the vessel not enter the first zone.

[067] Common to all examples in the Figures is the first part of the pipeline length 1' which is at a depth where protection is needed to prevent trawl nets and / or vessel anchors that could damage the pipeline. However, instead of protecting the first part of the pipeline length 1', the first part of the pipeline length 1' is uncovered and instead protected by monitoring vessels entering the second zone 20. Each vessel monitored in the second zone 20 and considered to be capable of causing damage to the first part of the pipeline length 1' is informed about the first zone 10 and / or requested not to enter the first zone 10. The means of monitoring and information may vary depending on specific project requirements, and may include, but are not limited to, the examples above: real and virtual AIS ATONS, S-AIS, AIS message, radar, visual inspection (camera), satellite phone, GMDSS, MF DSC, VHF and ECDIS etc.

[068] The invention is now explained with reference to non-limiting embodiments. However, a person skilled in the art will understand that alterations and modifications may be made to the embodiment which are within the scope of the invention as defined in the appended claims. List of references: 1 Pipeline 1' Length of the first section of the pipeline 1'' Length of the second section of the pipeline 1''' Length of the third section of the pipeline Petition 870260060096, dated 06 / 19 / 2026, page 26 / 30 / 17 2 seabed 3 Vessel 4 water surface 5 rocks 6 protection structure 10 first zone 20 second zone 30 real AIS 31 virtual AIS 40 coast 50 subsea installation 60 offshore installation Petition 870260060096, dated 06 / 19 / 2026, page 27 / 30

Claims

1 / 2 CLAIMS 1. Method for laying a pipeline (1) on the seabed (2), wherein the method comprises protecting the pipeline (1) with at least two types of protection, the method characterized by comprising the steps of: - bringing the pipeline (1) to an offshore location using a vessel (3), - laying the pipeline (1) on the seabed (2) using the vessel (3), - defining a first zone (10) encompassing at least a first part of the pipeline length (1') when laid underwater, wherein the first part of the length (1') is uncovered, - covering at least a second part of the pipeline length (1'') when laid on the seabed with a means of physical protection, - defining a second zone (20) extending from the first zone (10), leaving the length of the second part unmonitored, - monitoring by use of satellites and / or other tools to monitor activities in the second zone (20) for vessels approaching the first zone (10),- analyze the vessels detected during the aforementioned monitoring of the second zone (20), in order to determine if the vessels (20) can cause damage to the first part of the pipeline length (1'), - for each vessel monitored in the second zone (20) and considered capable of causing damage to the first part of the pipeline length (1'), inform the vessel about the first zone (1') and / or request that the vessel not enter the first zone (1').

2. Method according to claim 1, characterized in that said second zone (20) surrounds the first zone (10).

3. Method, according to claim 1 or 2, characterized in that said covering step comprises covering said second part of the pipe length (1'') with stones (5).

4. Method, according to claims 1 or 3, characterized in that said second part of the pipe length (1'') is placed in or near an offshore installation (50) and / or in or near the coast (40).

5. Method, according to any one of the preceding claims 1-4, characterized in that the submarine pipeline (1) is a fluid pipeline.

6. Method according to any one of the preceding claims 1-4, characterized in that the submarine pipeline (1) is a cable.

7. Method, according to any one of the preceding claims 1-4, characterized in that the submarine pipeline (1) is a combination of a fluid pipeline and a cable.

8. Method, according to any of the preceding claims, characterized in that the method comprises placing the piping (1) between an offshore installation and a satellite well.

9. Method, according to any one of the preceding claims 1-7, characterized in that the method comprises placing the pipeline (1) between an offshore installation (50) and the shore (40).

10. Method, according to any one of the preceding claims 1-7, characterized in that the method comprises placing the piping (1) between an offshore installation (60) and another offshore installation (60). Petition 870260060096, dated 19 / 06 / 2026, pp. 29 / 30

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