7th Pipeline Technology Conference 2012 THE CONCEPT OF A PIPE-LAYING VESSEL FOR THE RUSSIAN ARCTIC SHELF

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7th Pipeline Technology Conference 2012 THE CONCEPT OF A PIPE-LAYING VESSEL FOR THE RUSSIAN ARCTIC SHELF О.Ya.Timofeev, N.А.Valdman, N.L.Malyarenko, V.I.Tarovik, М.S.Trub Krylov Shipbuilding Research Institute, Russia E-mail: krylov5@krylov.

1 7th Pipeline Technology Conference 2012 THE CONCEPT OF A PIPE-LAYING VESSEL FOR THE RUSSIAN ARCTIC SHELF О.Ya.Timofeev, N.А.Valdman, N.L.Malyarenko, V.I.Tarovik, М.S.Trub Krylov Shipbuilding Research Institute, Russia krylov5@krylov.sp.ru The development of a pipe-laying vessel (PLV) for the Russian Arctic Shelf is a challenging and important task in view of the rich oil and gas deposits in this area. The large-scale plans for construction of subsea pipelines in Russia and abroad will provide abundant workload for such vessels. The specifications for PLV shall be selected to ensure optimum operation of the total integrated pipe-laying complex (pipe-laying vessels, auxiliary vessels and shore supply base) as well as the best execution of specific pipe-laying jobs with proper consideration of safety requirements pertinent to this process as well as to the maintenance of subsea pipelines. A PLV database, which has been generated, demonstrates that the existing vessels of this type are not fit for the harsh service environment of the Arctic. It is further planned to perform design studies and model tests in the seakeeping and ice basins to choose and justify the architecture and design type, hull lines as well as the configuration of pipe-laying, cargo handling and propulsion systems for the prospective vessel. Key words: concept, pipe-laying vessel, Arctic shelf, Russia. ABBREVIATIONS SSB shore supply bases SPS subsea production system DP dynamic positioning PLC pipe-laying complex PLV pipe-laying vessel SGCF Shtokman gas condensate field AMS anchor mooring system ROV remotely operated vehicle MTE mono ethylene glycol 1

2 1. Introduction The total length of existing subsea pipelines around the world reach over 60,000 km including over 42,000 km in the Gulf of Mexico, USA, about 13,000 km in the Northern Sea and Norwegian Sea, over 3,000 km in Russia. According to the forecast for 2013 it is expected to build another 5,000 km of pipelines including 2,400 km in Asia and Middle East, 1,700 km in the Northern Europe and Canada, 650 km in Africa and the Mediterranean Sea, and 250 km in the Gulf of Mexico. The pipe-laying complex (PLC) comprises: Pipe-laying vessel (PLV) and/or non-propelled pontoon (barge): 1-3 units for various jobs depending on the length, depth and specific details of the pipe-laying process. Support vessels of various types: units for providing as-required assistance depending on the PLV functions and specific design features of subsea pipelines. Shore supply bases (SSB) intended for preparation, storage as well as loading of pipes, metals, food, process equipment, service of support vessels. The number of shore supply bases depends on the length of subsea pipelines, distance from railways and roads, human settlements, sources of power and water supply as well as sea specifics. The subsea as well as land pipelines are classified by function into: Ffield pipelines connecting wells with various field facilities. Gathering pipelines connecting one field with another field with under water main pipeline. Main pipelines deliver hydrocarbons from the field to the points of transhipment, processing or consumption. Rigid steel pipes of mm in diameter with or without cement coating are used for gathering and main pipelines, and polymer metal (metal plastic) flexible pipes of mm are used for field pipelines. An average requirement for steel pipes to meet the needs of Russian gas pipelines in the period of is 300 to 700 thousand tons per year, which defines the demand for PLV in the years to come. The pipes of 1400 mm diameter account for 83%, 1200mm pipes account for 4%, mm pipes account for 13%. 2

Considering the water depths of subsea pipelines it may be expected that the following types of pipe-laying vessels will be required for Russia: PLV designed for sea water depths in the range of

3 Considering the water depths of subsea pipelines it may be expected that the following types of pipe-laying vessels will be required for Russia: PLV designed for sea water depths in the range of m (Russian shelf) PLV designed for coastal water areas with the depth range of 0 to 20 m and width range from 1.5 to 200km, where the following transit zones can be identified (Fig.1,Table 1): Zone А open sea with a water depth of 10m and deeper suitable for operation of common sea-going ships Zone B shallow water band between 10 and 3m depth lines, where the ship draft should be between 5 to 1.5m Zone C very shallow water band between 3 and 2 m depth lines, where a ship with 1.5m draft can start operation at the beginning of the navigation season given favorable combination of tidal currents and winds immediately following the ice cover receding to the North when the river runoff is contained by ice and the water level is maximum due to flood Zone D extremely shallow water band between 2m depth line and coastline, where the work can be performed using amphibious craft, e.g. air-cushion vehicles, tractors, all-terrain vehicles and shore winches. Fig.1 Transit zones of the Russian Shelf Transit zones of the Russian Shelf: Red lines high-opportunity areas; yellow lines moderate-opportunity areas 3

4 Table1. Opportunity gas reservoirs in the transit areas on the Russian Arctic Shelf Area Location Transit zone UPR, bln. m 3 Share depth, % 0-10m 10-20m Specific cost of resources $/km 2 Specific cost of recovery $/1000 m 3 1 Pechora Sea Kolguev- Pechora Kara Sea Sea of Okhotsk * - high-opportunity Yamal- Gydansk * Yamal- Gydansk Northern Kara* Northern Kara- Franz-Josef Bolshretsk- Okhotsk Western- Kamchatka Penzhinskaya Uda-Shantara Northern Sakhalin Terpeniya bay PLV Construction in Russia: State-of-the-art and Prospects The above-mentioned equipment and vessels have to lay 10 to 30km field pipelines with a diameter of mm intended to transfer a multi-phase flow, injection water, gas and MET. During construction of subsea production facilities the PLC facilities are also used for laying dozens of kilometers of flexible lines, umbilicals and gas manifolds intended to transfer multi-phase flow to a floating or shore-based processing facilities as well as for erection of the gathering manifolds, support metal structures, risers and subsea buoyancy tanks. The is no doubt that the field and gathering pipelines will be further developed due to extensive use of subsea production systems, in particular on the Arctic shelf. Russia plans to build about 9,000 km of subsea pipelines till 2035 (Table 2). The PLV specifications are chosen for optimum performance of the integrated PLC as well as the best execution of specific pipe-laying jobs. E.g., the main PLV characteristic, namely the load-carrying capacity governing the weight of pipes stored on the vessel s deck or hold, is chosen depending on the pipe diameter, thickness 4

5 and quantity as well as the number of welding stations, crane s lifting capacity and outreach, ship response in waves and performance in ice, and also on the cargocarrying capacity, design and numbers of vessels engaged in pipe transportation and the distance from shore supply bases. Particular attention should be paid to the safety of both pipe-laying process and operation of the subsea pipelines with due risk assessment studies. Table 2. Russia s subsea pipeline construction: Forecast till 2035 No of strings & Diameter, Project Max. depth, m length, km mm SGCF main pipelines (1 Shtokman SPC SGCF satellites 4х South Stream 2х180 (2 2х Blue Stream 2 2х70 ( ² 2х Pechora Sea Sakhalin Sakhalin 4 and Sakhalin Kara Sea, Ob bay and Taz bay Rusanovskoe field 3х Satellites and Rusanovskoe field SPC Leningradskoe field 3х Satellites and Leningradskoe field SPC Northern Kharasaveiskoe field Western Sharapovskoe field (2 Total 2100 (1 Shtokman gas condensate field; (2 the figure in the enumerator refers to S-lay method, the figure in denominator refers to J-lay method. The development of PLV for the Russian Arctic Shelf is a very challenging and high-priority task keeping in mind the rich hydrocarbon resources in the offshore waters of the Russian arctic seas, and the lack of PLV capable to operate at least in heavy ice and harsh climate. It s necessary to mark the positive experience of 3 pipe lay barges operation. This barges are owned by ZAO Mezhregionturboprovodstroi showed good performance in construction of the subsea pipelines in the Baidaratskaya Bay of the 5

Kara Sea (4х72km, diameter 1220 mm, capacity to the 140 bln m³), in the Nevelski Strait (23 km, diameter 2x1020 mm, capacity 36.5 bln m³) and in the Amur Bay. One of these barges is shown in Fig.

6 Kara Sea (4х72km, diameter 1220 mm, capacity to the 140 bln m³), in the Nevelski Strait (23 km, diameter 2x1020 mm, capacity 36.5 bln m³) and in the Amur Bay. One of these barges is shown in Fig.2. Fig.2 Pipe-laying barge Defender side by side with a pipe carrier Barge main data: Year of conversion 2008 Pipe diameter, mm Length between perpendiculars, m 135 Depth, m 7.5 Operating draft, m 3.8 Displacement, t Laying water depth, m up to 150 Crew, persons 220 Permissible wave height for pipe laying, m 2 Positioning system anchor system Crane No & capacity 2х250 Diesel-generator number and capacity, kw 3х1600 Production rate, km/day average/maximum 0.75/1.45 Tensioning devices number and pull, t 2х100 Welding stations number 6 Spare pipes, pcs Analysis of Data Base The data base covering 150 PLVs of maximum length (L max ) = m has been generated based on the data published in Offshore OilGas, Russian and foreign journals as well as studies of the Russian organizations. For quick search and data processing the data base is organized by the following sections: designer/builder company/owner, designation; main elements and devices; power plant; cargo handling gears; life-saving appliances; radio communication and radio navigation; navigation; series-built vessels. Fig.3 gives a 6

3D formats allowing the PLV designer to readily identify the trends and relationships between various parameters when the main

7 screen-shot of the section Main elements and devices (tab Pipe-laying equipment ). Fig.3 Screen shots Main information of the vessel The graphical data presentation makes use of various types of diagrams including 3D formats allowing the PLV designer to readily identify the trends and relationships between various parameters when the main engineering solutions are examined and chosen. The data base analysis leads to the following conclusions: The construction of vessels is progressively growing (Fig.4). 7

The number of PLV in 2011 was 150 units including newbuildings and conversions (up to 5 vessels converted annually). PLVs are operated by more than 20 companies.

4%, the pipe-laying jobs are performed by 73.4% of the PLC fleet. Some vessels (38%) employ the S-lay method using a stinger (central & sideway deployment) (Fig.5). Fig.

8 The number of PLV in 2011 was 150 units including newbuildings and conversions (up to 5 vessels converted annually). PLVs are operated by more than 20 companies. Pipe-laying barges make up the major part of the PLC fleet (55.3%), purely pipelaying vessels - 28%, purely support vessels %, and mixed-role vessels 45.4%, the pipe-laying jobs are performed by 73.4% of the PLC fleet. Some vessels (38%) employ the S-lay method using a stinger (central & sideway deployment) (Fig.5). Fig.4 PLV construction and conversion by years and generations (I-IV) Number, units I III built converted year Fig.5 Pipe-lay methods used for subsea pipeline construction The prevailing majority of vessels are of monohull design. 8

A few ships are strengthened to operate in less than 40 cm thick open floating ice. The prevailing majority of vessels (one third) are equipped with dynamic positioning systems (Fig.

7 Distribution of vessels by number of anchors As a rule the anchor mooring systems (AMS) have 8 mooring lines (Fig.7). Fig.

9 A few ships are strengthened to operate in less than 40 cm thick open floating ice. The prevailing majority of vessels (one third) are equipped with dynamic positioning systems (Fig.6), including upgraded class (DynPos-III) ~30%. Fig.6 Distribution of vessels by the type of positioning system Fig.7 Distribution of vessels by number of anchors As a rule the anchor mooring systems (AMS) have 8 mooring lines (Fig.7). Fig. 8 clearly shows that there are practically no PLVs suitable for the veryshallow-water zone C, 25% of the existing PLVs are designed for the shallowwater zone B, while the balance 75% PLVs аre designed for the open-sea zone. Therefore, the high-priority task is to develop a PLV (possibly an air cushion type) to serve the zones C & D. 9

water depths of 20-500m, including broken ice conditions (ice thickness up to 40 cm) storage, preparation, welding and paying out of steel pipes (measuring 500-1420 mm in diameter, 18m in length,

10 Fig. 8 PLV draft vs overall length Conceptual designs of the Krylov Shipbuilding Research Institute: Х - for open sea, О - for shallow waters 4. Main vectors of further studies The PLV should be designed for the following operations: laying of steel pipes (cement-coated or not) as well as laying of flexible metal plastic pipes in open sea, in water depths of m, including broken ice conditions (ice thickness up to 40 cm) storage, preparation, welding and paying out of steel pipes (measuring mm in diameter, 18m in length, wall thickness up to 40mm, service pressure of 25 MPa) as well аs possible handling of flexible pipes measuring mm in diameter, up to 12.5 mm wall thickness, spool length up to 300mm, stowing on reel under 4 MPa launching of pipes, umbilicals and cables via a tunnel with a smooth transition into a stinger in the middle of the hull to avoid ice effects in water depths up to 200m or via a vertical shaft in greater water depths positioning within the allowable error of 12.5m in longitudinal direction and ±2.5m in transverse direction, and relative bearing allowable error of ±1 deg. using super satellite systems GPS and GLONASS portable diving system for inspecting the pipe route, pipe lay and stinger structure in depths up to 100 m 10

11 portable remotely operated vehicle (ROV) to perform the following tasks in water depths of m: survey of perspective areas for future pipelines comprehensive monitoring of conditions in the area inspection of subsea pipelines, detection of damage locations and identification of measures to be taken. helicopter along with a helipad and hangar for stow and maintenance primarily intended for replacement of crews, flying of visiting personnel and patents for emergency medical treatment, delivery of small-size equipment and material packages as well as for long-distance ice management (survey of ice conditions and icebergs) drone mainly intended for ice management at distances up to 18km the vessel is to provide the accommodation, public and service spaces of required types, area and comfort level to suit the needs of personnel about 10 kn speed in open water in waves and up to 5 kn in ice conditions. The following engineering solutions were chosen for the design of a sea-going PLV to support the missions outlined above: a two-island design (Fig. 9) with accommodation spaces in the forward part of the vessel, process lines in the middle and engine room and hangars in the aft to provide the best work and leisure comfort to the personnel as well as the most favorable aircraft landing conditions principal particulars (molded lines - Fig.9): Length overall, m Beam, m.34 Draft, m...12 propulsion diesel-electric installation thrusters for propulsion and dynamic positioning 3 units forward and 2 units aft anchors of increased holding capacity 6 forward and 4 aft machinery operated by one operator from the main control panel room with unattended machinery spaces vessel s winterization and anti-icing system 11

centralized control system of cargo and ballast operations increased environment friendliness continuous operation at -30С air temperatures. Fig.

12 centralized control system of cargo and ballast operations increased environment friendliness continuous operation at -30С air temperatures. Fig. 9 One of the pipe-laying vessel variant under consideration a) Sea-going PLV (option) b) Moulded lines of sea-going PLV Conclusions: 12 The development of PLVs for the Russian Arctic Shelf is important in view of large-scale construction of subsea pipelines both around the globe as well as in Russia, in particular on the Arctic Shelf and transit zones. The existing pipe-laying vessels are practically unfit for operation in harsh climate conditions of the Arctic Shelf. In accordance with the Federal Target Program Development of civil marine engineering the conceptual designs of pipe-laying vessels for Arctic conditions as well as shallow water zones are developed under the contract with the Russian Ministry of Industry. In future it is recommended to work out a conceptual design of air-cushion pipelaying vessel for water depths of less than 3 m. For validation and optimization of certain engineering solutions it is planned to carry out model tests in the wave basin and ice basin.

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