DCV Aegir Pipelay Installation Analyses and Capabilities

2013 ◽  
Author(s):  
Henk Smienk ◽  
Erwan Karjadi ◽  
Gabriel Vazquez ◽  
Peter Doherty ◽  
Patrick Dooley
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
High Capacity ◽  
Design Review ◽  
New Era ◽  
Finite Element Software ◽  
Coating Type ◽  
The One ◽  
Pipeline Design ◽  
Tension Capacity

Heerema Marine Contractors (HMC) is entering a new era of pipe laying with the new Deep water Construction Vessel (DCV) Aegir, designed to be able to reel/J-lay pipelines for a broad range of pipe dimension and water depth combinations. On the one side this is governed by equipment/vessel limitations (moonpool size, high top tension capacity, stinger component capabilities) and on the other side limited by pipeline design code (e.g. DNV, API) acceptance criteria for reel-lay and J-lay installation. This paper outlines the pipelay capabilities of DCV Aegir and details the J-lay (with quad joints) and reel-lay installation analyses performed to aid in the design of the vessel pipelay equipment. DCV Aegir has two modes for J-lay installation, which are light J-lay with friction clamps and heavy J-lay with collar clamps in combination with collars in the pipeline. DCV Aegir reel-lay installation from the pipeline in the tensioners down to the seabed will also be explained. Light J-lay, heavy J-lay and reel-lay have maximum top tension capacities (related to the equipment) of 600 mT, 2000 mT and 800 mT, respectively. The top tension capacity also depends on pipe OD, coating type and thickness. J-lay and reel-lay installation analyses are performed with the non-linear finite element software package Flexcom from MCS Kenny to determine installation capabilities with respect to pipe OD, wall thickness and water depth combinations. Together with that the pipelay equipment design is validated by pipeline installation analyses. Shallow and deep water normal pipeline installation for all three pipelay options will be discussed. DCV Aegir pipelay equipment includes a retractable hang off module/stinger for deployment of pipelines. The usage and benefits of the hang off module will be documented. For the J-lay installation modes the procedure for lowering a quad joint is analysed in order to optimise equipment usage. DCV Aegir possesses a high capacity abandonment and recovery system (up to 2000mT). Abandonment and recovery analyses description and design review aspects will be discussed. Finally, the pipeline in-line structure installation analyses, together with design review considerations will be documented.

Extend Reel-Ability of HMC New Aegir Reeling Vessel Based on Reliability Based Assessment and Bending Tests Program

2012 ◽  
Author(s):  
Erwan Karjadi ◽  
Henk Smienk ◽  
Helen Boyd ◽  
Olav Aamlid
Keyword(s):  
Wall Thickness ◽  
Water Depth ◽  
Pipe Wall ◽  
Local Buckling ◽  
Acceptance Criteria ◽  
Pipe Wall Thickness ◽  
New Era ◽  
Water Pipeline ◽  
The One ◽  
Tension Capacity

Heerema Marine Contractors (HMC) is entering a new era of pipe laying using the reel-lay method for deep and shallow water pipeline installation projects. The new Deep water Construction Vessel (DCV) Aegir is designed to be able to reel/J-lay pipelines for a range of pipe dimension and water depth combinations which on the one side is governed by the equipment limitations (reel drum size, top tension capacity) and on the other side is limited by the code (DNV, API) acceptance criteria for reel/J-lay installation. The paper describes how the code standard acceptance criteria, which have been used to estimate the reel-ability of DCV Aegir and are generally known as conservative approach, can be relaxed in a reliable manner in order to safely extend the DCV Aegir reeling capability. This approach will permit a reduction of minimum reelable pipe wall thickness and result in a wider envelope of water depth applications for reeling from the DCV Aegir. The methodology of relaxation for local buckling and residual ovality criteria has been developed with and approved by DNV specifically for the spooling-on with the DCV Aegir configuration. A series of bend rig tests have been performed at Heriot-Watt University to confirm and validate the new proposed minimum reelable pipe wall thickness. In line with the development of the extended reeling capability, the required tighter specifications for seamless pipe purchased for reeling has been discussed.

PSI Armour Wire for High Collapse Performance of Flexible Pipe

2011 ◽  
Author(s):  
Laurent Paumier ◽  
Olivier Mesnage
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Production Systems ◽  
Dynamic Test ◽  
Full Scale ◽  
Flexible Pipe ◽  
Collapse Resistance ◽  
Potential Applications ◽  
Industrial Procurement ◽  
Tension Capacity

Ultra Deep Water (UDW) developments are now a reality with several fields below 2 000 m water depth now ready for production. Within the domain of flexible pipe technology for UDW, Technip identified a number of technical challenges such as flow assurance, riser tension capacity and hydrostatic collapse resistance. These challenges have been addressed through the qualification of various flexible pipe products/components and riser configurations. This paper will focus on one of the solutions developed which addresses the hydrostatic collapse resistance of the pipe, namely the dynamic PSI wire. The dynamic PSI wire was developed primarily as structurally optimized pressure armour. Based on the efficient structural cross section of the I-beam, the dynamic PSI wire provides a weight/strength optimized configuration for internal pressure capacity of the pipe. It also provides increased crushing strength for installation of the pipe in Ultra Deep Water and significantly increases the hydrostatic collapse resistance of the pipe. The objective of the development of the dynamic PSI wire was to propose a 12″ riser for 2 500 m water depth and smaller diameter down to 3 000 m. This objective has been reached, without impacting the dynamic and sour service capacity of the riser. The dynamic PSI wire has succeeded all the qualification process (industrial procurement & manufacturing, full scale dynamic test, full scale collapse tests, full scale offshore installation test down to 3 000m water depth, NACE test, etc) and is now deemed fully qualified for project application. This paper will present the qualification program and also some field case studies showing the potential applications of flexible risers integrating this new design. The availability of dynamic PSI wires provides operators with the opportunity to develop flexible riser production systems in UDW fields with larger diameters and therefore enhance the subsea production and export systems.

Mechanical Qualification of Dynamic Deep Water Power Cable

2011 ◽  
Author(s):  
Roger Slora ◽  
Stian Karlsen ◽  
Per Arne Osborg
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Failure Modes ◽  
Electrical Power ◽  
Oil And Gas Industry ◽  
Electrical Heating ◽  
Power Cable ◽  
Water Power ◽  
System Integrity ◽  
Water Depths

There is an increasing demand for subsea electrical power transmission in the oil- and gas industry. Electrical power is mainly required for subsea pumps, compressors and for direct electrical heating of pipelines. The majority of subsea processing equipment is installed at water depths less than 1000 meters. However, projects located offshore Africa, Brazil and in the Gulf of Mexico are reported to be in water depths down to 3000 meters. Hence, Nexans initiated a development programme to qualify a dynamic deep water power cable. The qualification programme was based on DNV-RP-A203. An overall project plan, consisting of feasibility study, concept selection and pre-engineering was outlined as defined in DNV-OSS-401. An armoured three-phase power cable concept assumed suspended from a semi-submersible vessel at 3000 m water depth was selected as qualification basis. As proven cable technology was selected, the overall qualification scope is classified as class 2 according to DNV-RP-A203. Presumed high conductor stress at 3000 m water depth made basis for the identified failure modes. An optimised prototype cable, with the aim of reducing the failure mode risks, was designed based on extensive testing and analyses of various test cables. Analyses confirmed that the prototype cable will withstand the extreme loads and fatigue damage during a service life of 30 years with good margins. The system integrity, consisting of prototype cable and end terminations, was verified by means of tension tests. The electrical integrity was intact after tensioning to 2040 kN, which corresponds to 13 000 m static water depth. A full scale flex test of the prototype cable verified the extreme and fatigue analyses. Hence, the prototype cable is qualified for 3000 m water depth.

Resistance Tests of an Articulated Pusher Barge System in Deep and Shallow Water

2021 ◽  
Author(s):  
Li Zhang ◽  
Lei Xing ◽  
Mingyu Dong ◽  
Weimin Chen
Keyword(s):  
Shallow Water ◽  
Water Depth ◽  
Deep Water ◽  
Water Resistance ◽  
Model Tests ◽  
System 2 ◽  
Changing Trend ◽  
The Difference ◽  
Transport Vessel ◽  
Resistance Performance

Abstract Articulated pusher barge vessel is a short-distance transport vessel with good economic performance and practicability, which is widely used in the Yangtze River of China. In this present work, the resistance performance of articulated pusher barge vessel in deep water and shallow water was studied by model tests in the towing tank and basin of Shanghai Ship and Shipping Research Institute. During the experimental investigation, the articulated pusher barge vessel was divided into three parts: the pusher, the barge and the articulated pusher barge system. Firstly, the deep water resistance performance of the articulated pusher barge system, barge and the pusher at design draught T was studied, then the water depth h was adjusted, and the shallow water resistance at h/T = 2.0, 1.5 and 1.2 was tested and studied respectively, and the difference between deep water resistance and shallow water resistance at design draught were compared. The results of model tests and analysis show that: 1) in the study of deep water resistance, the total resistance of the barge was larger than that of the articulated pusher barge system. 2) for the barge, the shallow water resistance increases about 0.4–0.7 times at h/T = 2.0, 0.5–1.1 times at h/T = 1.5, and 0.7–2.3 times at h/T = 1.2. 3) for the pusher, the shallow water resistance increases about 1.0–0.4 times at h/T = 2.7, 1.2–0.9 times at h/T = 2.0, and 1.7–2.4 times at h/T = 1.6. 4) for the articulated pusher barge system, the shallow water resistance increases about 0.2–0.3 times at h/T = 2.0, 0.5–1.3 times at h/T = 1.5, and 1.0–3.5 times at h/T = 1.2. Furthermore, the water depth Froude number Frh in shallow water was compared with the changing trend of resistance in shallow water.

High Holding Power Torpedo Pile: Results for the First Long Term Application

2004 ◽  
Author(s):  
Jairo Bastos de Araujo ◽  
Roge´rio Diniz Machado ◽  
Cipriano Jose de Medeiros Junior
Keyword(s):  
Water Depth ◽  
Deep Water ◽  
Field Tests ◽  
Free Fall ◽  
Mooring System ◽  
Holding Power ◽  
Campos Basin ◽  
Anchoring System ◽  
Very High

Petrobras developed a new kind of anchoring device known as Torpedo. This is a steel pile of appropriate weight and shape that is launched in a free fall procedure to be used as fixed anchoring point by any type of floating unit. There are two Torpedoes, T-43 and T-98 weighing 43 and 98 metric tons respectively. On October 2002 T-43 was tested offshore Brazil in Campos Basin. The successful results approved and certified by Bureau Veritas, and the need for a feasible anchoring system for new Petrobras Units in deep water fields of Campos Basin led to the development of a Torpedo with High Holding Power. Petrobras FPSO P-50, a VLCC that is being converted with a spread-mooring configuration will be installed in Albacora Leste field in the second semester of 2004. Its mooring analysis showed that the required holding power for the mooring system would be very high. Drag embedment anchors option would require four big Anchor Handling Vessels for anchor tensioning operations at 1400 m water depth. For this purpose T-98 was designed and its field tests were completed in April 2003. This paper discusses T-98 design, building, tests and ABS certification for FPSO P-50.

Development of Deep Water Multicolumn Buoy

2014 ◽  
Author(s):  
Rodrigo A. Barreira ◽  
Vinicius L. Vileti ◽  
Joel S. Sales ◽  
Sergio H. Sphaier ◽  
Paulo de Tarso T. Esperança
Keyword(s):  
Conceptual Design ◽  
Water Depth ◽  
Deep Water ◽  
Model Tests ◽  
Optimization Process ◽  
Life Duration

A new conceptual design of a deepwater MONOBUOY, named DeepWater MultiColumn Buoy (DWMCB), patent PCT/BR2011/000133, was developed by PETROBRAS/CENPES. The DWMCB was designed to be part of an offloading system for a Spread Moored Floating Production Offloading Unit (FPSO). The offloading system principle consists of Oil being exported from the FPSO to a Shutle tanker passing through Offloading Oil Lines (OOLs) that are supported by the DWMCB. The system is designed to operate at a water depth of 2,200 meters, with expected in site life duration of 25 years. The geometry of DWMCB was defined after an optimization process in order to minimize its motions. This paper describes the development of this concept and discusses the results from some design verifications done with the help of a model tests campaign. An equivalent traditional shaped monobuoy was also tested for comparison purposes.

scholarly journals Deep permafrost evolution in unstable slopes during the Holocene

2018 ◽  
Author(s):  
Julien Seguinot
Keyword(s):  
Slope Failure ◽  
Time Lag ◽  
Great Influence ◽  
Ground Surface ◽  
Heat Diffusion ◽  
Failure Initiation ◽  
Finite Element Software ◽  
Hand Model ◽  
The One ◽  
Ice Pressure

Large alpine landslides dynamics are generally associated with Quaternary glacier retreat. Some recent datations demonstrate that several thousand years can separate the slope failure initiation from ice pressure unloading. The current study addresses the question whether the persistence of deep permafrost could produce this time lag. A model of deep permafrost evolution is developed, including heat diffusion, phase change and a ground surface transfer function. It is numerically implemented by a 1D finite difference code on the one hand and into a 2D finite element software on the other hand. Model results reveals the great influence of porosity and near-ground processes in permafrost evolution, and illustrates the possible persistence of a permafrost core into the slope.

scholarly journals Elements constituent for the design of a riser system in areas deep water and extreme deep water applied for offshore drilling

2020 ◽  
Vol 6 (3) ◽  
pp. 127-144
Author(s):  
Marius STAN ◽  
◽  
Valentin Paul TUDORACHE ◽  
Lazăr AVRAM ◽  
Mohamed Iyad AL NABOULSI ◽  
...  
Keyword(s):  
Working Conditions ◽  
Water Depth ◽  
Deep Water ◽  
Environmental Conditions ◽  
Oil And Gas ◽  
Operational Mode ◽  
Exploration And Exploitation ◽  
Offshore Drilling ◽  
The Stability ◽  
Marine Platform

Riser systems are integral components of the offshore developments used to recover oil and gas stored in the reservoirs below the earth’s oceans and seas. These riser systems are used in all facets of the development offshore process including exploration and exploitation wells completion/intervention, and production of the hydrocarbons. Their primary function is to facilitate the safe transportation of material, oil and gases between the seafloor oceans and seas and the marine platform. As the water depth increases, the working conditions of this system becomes challenging due to the complex forces and extreme environmental conditions which are impacting the operational mode as well as the stability. In this paper several aspects concerning riser mechanics and the behaviour of the riser column will be evaluated against different operational situations.

scholarly journals Effects of Water Depth on the Growth of the Submerged Macrophytes Vallisneria natans and Hydrilla verticillata: Implications for Water Level Management

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2590
Author(s):  
Qisheng Li ◽  
Yanqing Han ◽  
Kunquan Chen ◽  
Xiaolong Huang ◽  
Kuanyi Li ◽  
...  
Keyword(s):  
Water Level ◽  
Water Depth ◽  
Deep Water ◽  
Submerged Macrophytes ◽  
Hydrilla Verticillata ◽  
Water Level Fluctuations ◽  
Total Biomass ◽  
Intermediate Water ◽  
Factors Affecting ◽  
Vallisneria Natans

Water level is one of the most important factors affecting the growth of submerged macrophytes in aquatic ecosystems. The rosette plant Vallisneria natans and the erect plant Hydrilla verticillata are two common submerged macrophytes in lakes of the middle and lower reaches of the Yangtze River, China. How water level fluctuations affect their growth and competition is still unknown. In this study, three water depths (50 cm, 150 cm, and 250 cm) were established to explore the responses in growth and competitive patterns of the two plant species to water depth under mixed planting conditions. The results show that, compared with shallow water conditions (50 cm), the growth of both submerged macrophytes was severely suppressed in deep water depth (250 cm), while only V. natans was inhibited under intermediate water depth (150 cm). Moreover, the ratio of biomass of V. natans to H. verticillata gradually increased with increasing water depth, indicating that deep water enhanced the competitive advantage of V. natans over H.verticillata. Morphological adaptation of the two submerged macrophytes to water depth was different. With increasing water depth, H. verticillata increased its height, at the cost of reduced plant numbers to adapt to poor light conditions. A similar strategy was also observed in V. natans, when water depth increased from 50 cm to 150 cm. However, both the plant height and number were reduced at deep water depth (250 cm). Our study suggests that water level reduction in lake restoration efforts could increase the total biomass of submerged macrophytes, but the domination of key plants, such as V. natans, may decrease.

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