23 results on '"offshore platform"'
Search Results
2. Analysis of gas preparation processes for improvement of gas transportation technology
- Author
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Abdulaga Gurbanov, Ijabika Sardarova, and Javida Damirova
- Subjects
gas pipeline ,separator ,QC1-999 ,Clathrate hydrate ,General Physics and Astronomy ,Separator (oil production) ,Liquefied petroleum gas ,condensate ,chemistry.chemical_compound ,viscosity elastic composition ,TJ1-1570 ,shearing stress ,Mechanical engineering and machinery ,thermodynamic parameters ,hydrate formation ,Petroleum engineering ,liquid phase ,Dry gas ,Physics ,General Engineering ,pipeline ,offshore platform ,Petrochemical ,Dew point ,Volume (thermodynamics) ,chemistry ,Environmental science ,Submarine pipeline - Abstract
At production, collection and transport of low – pressure gas to deep water offshore platforms in sea conditions because of thermodynamic indices change in the system, complications are generated in connection with liquid phases – separation. These complications disturb normal operational well behavior, gas preparation unit and trunk (main) pipeline conditions. As a result of these phenomena high – volume losses of gas, gas condensate and chemical reagent take place. In the process of testing, the following process parameters were determined: pressure, gas temperature, facility performance, regeneration temperature, amount of absorbent injected into the gas flow, concentration of regenerated and saturated absorbent, dry gas dew point and so on. In the process of investigating the effect of the amount of inhibitor on the degree of corrosion prevention, hydrate formation and salt deposit at the facilities, regression equations. That is why, to guarantee uninterrupted transportation of low-pressure gas in field conditions, new methods are required for these phenomena prevention. On the basis of field study results some variants of calculation were given to increase efficiency of low-pressure gas transportation system in offshore oil and gas field’s conditions. Results of high-pressure gas optimal working pressure calculation for precipitated liquid phase displacement at low-pressure petroleum gas transportation to deepwater offshore platforms are shown in the article. As well, method for precipitated liquid phase displacement from low-pressure gas pipeline with usage of high-viscosity elastic gelling compositions on the basis of domestic petrochemical products
- Published
- 2021
3. Towards a resilient perspective for the future of offshore platforms. Insights from a data driven approach
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Nunzia Capobianco, Roberto Vona, Francesca Loia, Loia, F., Capobianco, N., and Vona, R.
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Information Systems and Management ,Circular economy ,Resilience ,Public Administration ,business.industry ,Perspective (graphical) ,Environmental resource management ,Data driven approach ,Offshore platform ,Nuclear decommissioning ,Computer Science Applications ,Data-driven ,Green governance ,Submarine pipeline ,Business ,Resilience (network) ,Decommissioning - Abstract
Purpose This study aims to investigate the collective perception regarding the future of offshore platforms and frame the main categories of meanings associated by the community with the investigated phenomenon. Design/methodology/approach A data driven approach has been conducted. The collection of the peoples’ opinions has been realized on two specific social network communities as follows: Twitter and Instagram. The text mining processes carried out a sentiment and a cluster analysis. Findings The sentiment analysis of the most frequent words has been shown. The following four main homogeneous categories of words are emerged in relation to the decommissioning of offshore platforms: technological areas, green governance (GG), circular economy and socio-economic sphere. Research limitations/implications The alternative use of the offshore platforms, including tourism initiatives, aquaculture, alternative energy generation, hydrogen storage and environmental research, could improve the resilience of communities by offering the development of new jobs and the growth of local and innovative green businesses. Practical implications The adoption of a circular model and GG initiatives aims to limit the input of resources and energy, minimize waste and losses, adopt a sustainable approach and realize new social and territorial value. Originality/value The analysis underlines the importance to adopt a systems perspective, which takes into account the social, economic and environmental system as a whole, the different phenomena that occur and the variety of categories of stakeholders, from users to local governments that participate in the territorial development.
- Published
- 2021
4. Risk Assessment Approaches for Offshore Structures
- Author
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Nourhan I. Ghoneim, Mohamed R. Shouman, and Mostafa El-Khatib
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formal safety assessment (fsa) ,offshore structures ,risk assessment ,Ocean Engineering ,Transportation ,Canals and inland navigation. Waterways ,hazard identification (hazid) ,Oceanography ,offshore platform ,qra ,risk matrix ,TC601-791 ,Environmental science ,Submarine pipeline ,Risk assessment ,Environmental planning ,risk index (ri) ,Transportation and communications ,HE1-9990 - Published
- 2021
5. Bioactive Ceramic Coating Solution for Offshore Floating Wind Farms
- Author
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Laura Trueba, David Salvador Sanz, Alfredo Trueba, Sergio García, and Universidad de Cantabria
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Materials science ,Metallurgy ,offshore structures ,Canals and inland navigation. Waterways ,Ocean Engineering ,Transportation ,offshore wind farms ,offshore platform ,Oceanography ,Ceramic coating ,floating wind farms ,bioactive ceramic coating ,offshore floating wind farms ,maritime wind farms ,TC601-791 ,Submarine pipeline ,Transportation and communications ,ceramic coating ,HE1-9990 - Abstract
Biofouling is a natural phenomenon that consists of the accumulation of living organisms on an artificial surface submerged or in contact with water like Offshore platforms. This study highlights the need for offshore floating wind farms structures to consider the choice of material used in offshore applications to minimize microbial-associated and corrosion problems. For this purpose, differences in the total of seawater biofouling attached on two coated paints and three ceramic coatings in carbon steel for offshore structures were evaluated and compared. All ceramic coatings were made of incorporating, by electrophoretic deposition, active ceramic particles against biofouling as copper, silver, zinc and titanium. This experiment consisted of testing ceramic coatings and conventional paints in a real environment with high biological activity and at the same time in a shallow marine environment for a period of 1 year, which provided positive comparisons with the standard system (ASTM-D3623) for using in protecting offshore marine structures.
- Published
- 2021
6. Method for determining the design load of an aluminium handrail on an offshore platform
- Author
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Dong Hun Lee, Jung Kwan Seo, Joo Shin Park, and Kim Yeon Ho
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Computer science ,Naval architecture. Shipbuilding. Marine engineering ,Probabilistic logic ,Handrail ,Offshore platform ,Probabilistic approach ,VM1-989 ,Design load ,Trial and error ,Reliability engineering ,Ocean engineering ,Variable (computer science) ,Control and Systems Engineering ,Acceptance testing ,Aluminium ,Analysis software ,Submarine pipeline ,TC1501-1800 ,Deterministic approach - Abstract
Aluminium outfitting is widely used in offshore platforms owing to its anti-corrosion ability and its light weight. However, various standards exist (ISO, NORSOK and EN) for the design of handrails used in offshore platforms, and different suppliers have different criteria. This causes great confusion for designers. Moreover, the design load required by the standards is not clearly defined or is uncertain. Thus, many offshore projects reference previous project details or are conservatively designed without additional clarification. In this study, all of the codes and standards were reviewed and analysed through prior studies, and data on variable factors that directly and indirectly affect the handrails applied to offshore platforms were analysed. A total of 50 handrail design load scenarios were proposed through deterministic and probabilistic approaches. To verify the proposed new handrail design load selection scenario, structural analysis was performed using SACS (offshore structural analysis software). This new proposal through deterministic and probabilistic approaches is expected to improve safety by clarifying the purpose of the handrails. Furthermore, the acceptance criteria for probabilistic scenarios for handrails suggest considering the frequency of handrail use and the design life of offshore platforms to prevent excessive design. This study is expected to prevent trial and error in handrail design while maintaining overall worker safety by applying a loading scenario suitable for the project environment to enable optimal handrail design.
- Published
- 2021
7. Safety evaluation of LD27-2 WHPB platform based on rod pumping
- Author
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Yanqun Yu, Xiaoguang Huang, and Zhiming Yin
- Subjects
020209 energy ,Offshore platform ,Mechanical properties ,02 engineering and technology ,010502 geochemistry & geophysics ,01 natural sciences ,Stress (mechanics) ,0202 electrical engineering, electronic engineering, information engineering ,Safety coefficient ,Oil field ,Petroleum refining. Petroleum products ,Rod pumping ,0105 earth and related environmental sciences ,Petrology ,Hydraulic pumping unit ,QE420-499 ,Geotechnical Engineering and Engineering Geology ,Finite element method ,Probability model ,Wind engineering ,General Energy ,Joint distribution of extreme ,Offshore geotechnical engineering ,Submarine pipeline ,TP690-692.5 ,Marine engineering - Abstract
The development of heavy oil with high efficiency is a worldwide difficulty for offshore oil field. The technology of rod pumping provides a possible effective way for offshore heavy oil thermal recovery, but the safety of working platform is the prerequisite for the implementation of this new technology. In this paper, the mechanical model of LD27-2 WHPB platform is established, and the safety performance of the platform under hydraulic pumping unit (HPU) load is evaluated. The distribution of the combined HPU load accords with the classical probability model. When the HPUs are all synchronous, the combined load reaches its maximum. The finite element-based platform safety analysis under the extreme condition is carried out. Under the combined action of wave current, wind load and the extreme HPU load, the maximum stress of the jacket is 83.2 MPa, and the safety coefficient is 4.33, indicating the overall strength of LD27-2 WHPB platform meets the safety requirement.
- Published
- 2020
8. Design of an aeroelastic physical model of the DTU 10MW wind turbine for a floating offshore multipurpose platform prototype
- Author
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Hermes Giberti, Alan Facchinetti, S. Di Carlo, Sara Muggiasca, Marco Belloli, Federico Taruffi, and Alessandro Fontanella
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Environmental Engineering ,Scale (ratio) ,business.industry ,Computer science ,Complex system ,Multi-function platform ,Offshore platform ,Ocean Engineering ,Modular design ,Aeroelasticity ,Turbine ,Aeroelastic model ,Key (cryptography) ,Submarine pipeline ,FOWT ,business ,Wind energy ,Scale model ,Blade design ,Marine engineering - Abstract
Multi-purpose offshore structures are very complex systems to be designed as many different requirements have to be taken into account simultaneously. Experimental tests on scaled models can be very useful to verify structural behavior and to validate numerical models. The definition of the scale can play a key role in performing tests as high scales, closer to full-scale, are generally related to more reliable results. The present paper concerns the design of a wind turbine model for a large-scale model of a Multi-purpose offshore Platform developed within the EU project H2020 Blue Growth Farm. This project aims at developing an offshore farm, based on a modular floating structure that integrates wave energy converters and a wind turbine with aquaculture. The scale model of the complete structure will be deployed at the Natural Ocean Engineering Laboratory (NOEL). The paper will focus on the strategies adopted to scale 1:15 the DTU 10 MW wind turbine in order to represent both the main aeroelastic features and all the functionalities of a real machine. The complete design of the machine and its control will be also provided.
- Published
- 2021
9. Research on new technology for offshore heavy oil thermal recovery with rod pumping
- Author
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Feng Dehua, Yanqun Yu, Yaoguang Qi, and Zong-yu Chang
- Subjects
Engineering ,020209 energy ,Offshore platform ,Mature technology ,02 engineering and technology ,lcsh:Petrology ,0202 electrical engineering, electronic engineering, information engineering ,Oil field ,lcsh:Petroleum refining. Petroleum products ,Leakage (electronics) ,Oil recovery with rod pumping ,Thermal recovery ,Petroleum engineering ,business.industry ,Hydraulic pumping unit ,Downhole safety ,lcsh:QE420-499 ,Geotechnical Engineering and Engineering Geology ,Wellhead safety ,General Energy ,Thermal recovery of heavy oil ,lcsh:TP690-692.5 ,Wellhead ,Sucker rod ,Offshore geotechnical engineering ,Submarine pipeline ,business ,Marine engineering - Abstract
The high-efficient development of heavy oil is difficult for offshore oil field. Based on the mature technology of onshore heavy oil thermal recovery, a new rod pumping technology of “heavy oil steam stimulation along with conventional sucker rod pumping system” is proposed. According to the structure space of aimed offshore platform, we designed one new kind of miniature hydraulic pumping unit with long-stroke, low pumping speed and compact structure. The paper also studies the offshore heavy oil thermal recovery well safety technology, establishes a leakage model of wellhead sealing and a mechanical model of sealed rubber sleeve on downhole nonlinear large deformation. The study shows that a series of equipment for offshore rod pumping oil recovery and the key technology of well safety lay a solid foundation for carrying out rod pumping of offshore heavy oil thermal recovery.
- Published
- 2017
10. Formation diagnostics of salt deposits polluted by natural radionuclides in pipelines of offshore oil & gas production rigs
- Author
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N. L. Kuchin, Yu. Vishnyakov, V. Balabin, and S. Yemelyanov
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chemistry.chemical_classification ,Radionuclide ,natural radionuclide ,Waste management ,Tl-208 radionuclide ,lcsh:Naval architecture. Shipbuilding. Marine engineering ,Salt (chemistry) ,offshore platform ,Natural (archaeology) ,Pipeline transport ,lcsh:VM1-989 ,chemistry ,instrumentation & calculation system ,Environmental science ,Submarine pipeline ,hydrocarbons - Abstract
Object and purpose of research. This study is dedicated to formation control of salt deposits polluted by natural radionuclides inside flow columns of subsea wells. The purpose of the study is to determine the optimal set of prevention measures for further salt deposit formation within the entire production system of an offshore oil & gas production rig. Materials and methods. Compact instrumentation & calculation hardware installed on pipes, as well as measurement and data processing algorithm for early detection of radioactive salt deposits inside flow columns. Main results. The study suggests equipment and a radiometric method for early detection of salt deposits inside flow columns, as well as demonstrates early detection possibility for 1-2 mm thick salt deposit containing Tl-208 with minimum specific activity of ~0.15 Bq/g, with reliable detection probability 1-β = 0.9 at false alarm level α = 0.01. Application of detection units with BGO or CsJ(Tl) will enable detection of even thinner radioactive salt deposits. Conclusion. The possibility to detect salt deposits at early stages, without interruption of the production process and, consequently, without production loss, as well as the possibility to promptly inform the operator of the platform’s main control room about the beginning of salt deposit formation will make it possible to launch the optimal strategy of combatting further salt deposit development in pipeline and equipment of the entire production system of the platform.
- Published
- 2017
11. Loadings on the topside of a gravity based offshore structure due to drifting ice pieces by extreme waves
- Author
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M. Hasanat Zaman, Ayhan Akinturk, and Dong Cheol Seo
- Subjects
Drift ice ,ice pieces ,ice loading on the topside ,extreme waves ,Collision ,offshore platform ,Harshness ,Submarine pipeline ,Rogue wave ,Air gap (plumbing) ,Significant wave height ,Seismology ,Geology ,Physics::Atmospheric and Oceanic Physics - Abstract
The motion of the ice pieces of various sizes in the Northern Seas such as, in the Grand Bank area of Newfoundland and Labrador always imposes extra risks to the operations of the offshore fixed and floating structures. In stormy weather, the operation and safety of such offshore structures are greatly affected when heavy waves propagate over the region with drifting ice pieces. This can cause damages to the structures when the interaction between those ice pieces and structures occurs. The range of severity of such damages depends on the harshness of the wave actions and the diversity of the ice pieces. In this paper, small ice pieces of different sizes are used in the simulations of interactions with an offshore Concrete Gravity Based Structure (CGBS). The motions of the ice pieces of various geometries and their dynamic impacts on the structures are studied. The simulations are carried out using a commercial numerical solver to predict the trajectory of the ice pieces around the structures, possible interaction with the CGBS and their consequent loadings on different elements of the structure at interest. The outcomes of the simulations obtained from single and multiple realizations of several wave conditions for the vertical impact loads due to ice pieces colliding with the topside so far. The initial results show that an increase of the significant wave height increases the number of collisions with the structure significantly. The magnitudes of the ice impact forces on the topsides did not follow the same trend. In each data set, the average of the highest one- third of the impact forces increases with the increase of Significant Wave Height / Air Gap ratios. The effects of variations in wave realizations for sea states are reported in the paper. The simulations also show the importance and possibilities of incorporating loads due to a collision of the ice pieces with the topside in the design process of such structures in the ocean., Oceans-2019, October 27-31, 2019, Seattle, Washington
- Published
- 2019
12. Automatic Extraction of Offshore Platforms in Single SAR Images Based on a Dual-Step-Modified Model
- Author
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Jing Zhang, Qi Wang, and Fenzhen Su
- Subjects
Synthetic aperture radar ,two-parameter CFAR detection ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,02 engineering and technology ,Interference (wave propagation) ,lcsh:Chemical technology ,01 natural sciences ,Biochemistry ,Article ,Analytical Chemistry ,Hough transform ,law.invention ,Constant false alarm rate ,law ,Radar imaging ,0202 electrical engineering, electronic engineering, information engineering ,Extraction (military) ,lcsh:TP1-1185 ,Electrical and Electronic Engineering ,single SAR image ,Instrumentation ,computer.programming_language ,Remote sensing ,010401 analytical chemistry ,020206 networking & telecommunications ,offshore platform ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,PEARL (programming language) ,Submarine pipeline ,computer ,dual-step-modified model ,Geology - Abstract
The quantity and location of offshore platforms are of great significance for marine oil spill monitoring and offshore oil-gas development. In the past, multiphase medium- and low-resolution optical or radar images have been used to remove the interference of ship targets based on the static position of a platform to extract the offshore platform, resulting in large demands and high image data costs. According to the difference in shape between offshore platforms (not elongated) and ships (elongated shapes) in SAR (synthetic aperture radar) images, this paper proposes an automatic extraction method for offshore platforms in single SAR images based on a dual-step-modified model. First, the two-parameter CFAR (constant false alarm rate) algorithm was used to detect the possible offshore platform targets, then, the Hough transform was introduced to detect and eliminate ship targets with linear structures. Finally, the final offshore platform was obtained. Experiments were carried out in four study areas in the Beibu Gulf basin and the Pearl River estuary basin in the northern South China Sea. The results show that the method has a good extraction effect in the above research area, and the extraction accuracy rate of offshore platforms is 86.75%. A single SAR image can obtain satisfactory extraction results, which greatly saves on image data cost.
- Published
- 2019
13. A methodology for multi-criteria design of multi-use offshore platforms for marine renewable energy harvesting
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Elisa Angelelli, Yukiko Krontira, Phoebe Koundouri, Barbara Zanuttigh, Kaan Koca, Andreas Kortenhaus, Zanuttigh, Barbara, Angelelli, Elisa, Kortenhaus, Andrea, and Koca, Kaan
- Subjects
Engineering ,Wind power ,Renewable Energy, Sustainability and the Environment ,business.industry ,Wave energy ,020209 energy ,Environmental resource management ,Offshore platform ,Multi-use ,Marine spatial planning ,Aquaculture ,02 engineering and technology ,Renewable energy ,Offshore wind power ,Ranking ,Software deployment ,Multi criteria ,0202 electrical engineering, electronic engineering, information engineering ,Systems engineering ,Multi-criteria methodology ,Submarine pipeline ,business ,Wind energy - Abstract
Multi-use offshore platforms (MUPs) combining renewable energy from the sea, aquaculture and transportation facilities can be considered as a challenging way to boost blue growth and make renewable energy (especially wave energy) environmentally and socio-economically sustainable. MUPs allow sharing the financial and other market/non-market costs of installation and management, locally using the produced energy for different functionalities and optimizing marine spatial planning. The design of these solutions is a complex interdisciplinary challenge, involving scientists and technical experts with different backgrounds. This paper presents a new methodology for the design of a MUP based on technical, environmental, social and economic criteria. The methodology consists of four steps: a pre-screening phase, to assess the feasibility of different maritime uses at the site; a preliminary design of the alternative schemes based on the identified maritime uses; a ranking phase, where the performance of the MUPs is scored by means of expert judgment of the selected criteria; a preliminary design of the selected MUP selected. An example application of this procedure to a site offshore the Western Sardinia coast, Mediterranean Sea, Italy, is provided. In this site the deployment of a MUP consisting of wave energy converters, offshore wind turbines and aquaculture is specifically investigated.
- Published
- 2016
14. Anti-Explosion Performance of Composite Blast Wall with an Auxetic Re-Entrant Honeycomb Core for Offshore Platforms
- Author
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Shilian Zhang, Deqing Yang, and Fang Luo
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Materials science ,Auxetics ,Composite number ,corrugated plate ,Ocean Engineering ,02 engineering and technology ,Impulse (physics) ,01 natural sciences ,lcsh:Oceanography ,lcsh:VM1-989 ,Energy absorption ,Indentation ,0103 physical sciences ,blast wall ,lcsh:GC1-1581 ,Water Science and Technology ,Civil and Structural Engineering ,010302 applied physics ,distributed impulse loads ,auxetic ,business.industry ,lcsh:Naval architecture. Shipbuilding. Marine engineering ,Structural engineering ,offshore platform ,021001 nanoscience & nanotechnology ,re-entrant honeycomb ,Honeycomb structure ,negative poisson’s ratio ,Submarine pipeline ,Re entrant ,explosion ,0210 nano-technology ,business - Abstract
To improve the anti-explosion performance of blast wall in offshore platforms, an auxetic re-entrant blast wall (ARBW) was proposed and designed based on the indentation resistance effect of an auxetic structure. Based on the numerical nonlinear dynamic analysis method verified by the explosion experiment of a conventional steel corrugated blast wall (CBW), the failure mechanisms of ARBW, steel honeycomb sandwich blast wall (HSBW) and CBW were investigated under distributed impulse loads. Computational results demonstrated the excellent anti-explosion performance of the proposed ARBW design. Concerning the minimal deformation at the mid-point of the proposed protective structures, the ARBW performed best. As regards the minimal deformation at the connection, both ARBW and HSBW worked well. The stress distribution of the connection illustrated the different energy absorption and transmission modes of the three blast walls.
- Published
- 2020
15. Long Term Effectiveness of Life Extension Methodologies Applied to Offshore Structures
- Author
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P. J. Haagensen, O.T. Vårdal, and J.E. Larsen
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Engineering ,business.industry ,General Engineering ,Peening ,Fatigue damage ,General Medicine ,Welding ,offshore platform ,Water leakage ,law.invention ,Life extension ,Cracking ,Safe operation ,law ,repair ,Forensic engineering ,Retrofitting ,General Materials Science ,Submarine pipeline ,business ,Fatigue - Abstract
This paper documents developments in fatigue cracking of a floating platform that required repair and upgrading during 1999–2000. The Veslefrikk B (VFB) platform was built in 1985 for drilling exploration but was converted to a production platform in 1989. Shortly thereafter extensive fatigue cracking was discovered and several repairs were made. However, extensive fatigue cracking continued and a retrofitting program was implemented, using various types of grinding and peening techniques. In 1999 the platform was temporarily decommissioned and dry-docked for a comprehensive repair and upgrading program, following the International Institute of welding (IIW) guidelines for weld improvement methods [1] , this was completed in only four months. However, after a few more years of service fatigue damage again necessitated new repairs. The majority of cracks occurred in the hull skin plates and caused water leakage. It is noteworthy that cracking this time occurred only in areas of the structure that were left untreated in the first retrofitting program due to low levels of stress from FE analyses in these areas. The paper describes the original repair and strengthening program, and the types of subsequent fatigue damage that necessitated new repairs. The recent life extension program has resulted in the safe operation of the platform for an estimated additional period of 20 years.
- Published
- 2014
16. Preliminary Design for Wave Run-Up in Offshore Wind Farms: Comparison between Theoretical Models and Physical Model Tests
- Author
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Javier Barba, Jorge Luengo Frades, Vicente Negro, M. Dolores Esteban, Luis J. Moreno Blasco, Mario Martín-Antón, José-Santos López-Gutiérrez, Universidad de Alicante. Departamento de Ingeniería Civil, and Ingeniería del Terreno y sus Estructuras (InTerEs)
- Subjects
cylinder ,Control and Optimization ,Scale (ratio) ,020209 energy ,Cylinder ,Offshore platform ,Energy Engineering and Power Technology ,02 engineering and technology ,GBS ,lcsh:Technology ,01 natural sciences ,foundation ,010305 fluids & plasmas ,symbols.namesake ,Benchmark (surveying) ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Froude number ,Foundation ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,hydraulic model tests ,Hydraulic model tests ,lcsh:T ,Renewable Energy, Sustainability and the Environment ,run-up ,Elevation ,Foundation (engineering) ,Experimental data ,Run-up ,Ingeniería del Terreno ,Offshore wind power ,symbols ,Submarine pipeline ,Geology ,Energy (miscellaneous) ,Marine engineering - Abstract
Estimation of wave run-up has been of increasing concern for offshore wind structures and a critical aspect for designers. The highly nonlinear phenomenon makes the study difficult. That is the reason for the very few design rules and experimental data available to estimate it. Actual wave run-up is greater than commonly predicted. The goal of this research is to benchmark the theoretical formulations with the results of the physical model tests performed by Deltares in the field of crest elevation, run-up, forces and pressures. The laboratory reproduced in a wave tank (75 m length; 8.7 m width; 1 m depth; and a 1:60 scale, with Froude similarity) an offshore power converter platform located at intermediate water depths (25–43.80 m) in the Southern North Sea, designed by the Norwegian company Aibel. The purpose of this research is to offer a preliminary design guide for wave run–up using theoretical expressions both for cylinders and gravity based structures (GBS), leaning on the cited laboratory tests to validate the results obtained by such theoretical models. This research was funded by La Caixa PhD Program Fellowship.
- Published
- 2019
17. Simplified model of offshore Airborne Wind Energy Converters
- Author
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Marco Fontana, Antonello Cherubini, Rocco Vertechy, Cherubini, Antonello, Vertechy, Rocco, and Fontana, Marco
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Engineering ,Wind power ,AWE ,business.industry ,Renewable Energy, Sustainability and the Environment ,020209 energy ,Wave energy ,Offshore platform ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,02 engineering and technology ,Converters ,Power (physics) ,High altitude wind ,Offshore renewable ,Floating ,Wind wave ,0202 electrical engineering, electronic engineering, information engineering ,Submarine pipeline ,business ,Energy (signal processing) ,Marine engineering ,Crosswind - Abstract
Airborne Wind Energy Converters (AWECs) are promising devices that, thanks to tethered airborne systems, are able to harvest energy of winds blowing at an altitude which is not reachable by traditional wind turbines. This paper is meant to provide an analysis and a preliminary evaluation of an AWEC installed on a floating offshore platform. A minimum complexity dynamic model is developed including a moored heaving platform coupled with the dynamics of an AWEC in steady crosswind flight. A numerical case study is presented through the analysis of different geometrical sizes for the platform and for the airborne components. The results show that offshore AWECs are theoretically viable and they may also be more efficient than grounded devices by taking advantage of a small amount of additionally harvested power from ocean waves.
- Published
- 2016
18. Stakeholders Opinions on Multi-Use Deep Water Offshore Platform in Hsiao-Liu-Chiu, Taiwan
- Author
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Yang-Chi Chang, Ya-Tsune Sie, Pierre-Alexandre Château, and Shiau-Yun Lu
- Subjects
0106 biological sciences ,Conservation of Natural Resources ,Process (engineering) ,Oceans and Seas ,Health, Toxicology and Mutagenesis ,Causal loop diagram ,Fisheries ,Taiwan ,causal-loop diagram ,lcsh:Medicine ,group model building ,010603 evolutionary biology ,01 natural sciences ,Article ,stakeholders ,Extreme weather ,Humans ,Systems thinking ,14. Life underwater ,Recreation ,business.industry ,010604 marine biology & hydrobiology ,lcsh:R ,Environmental resource management ,systems thinking ,Public Health, Environmental and Occupational Health ,Group model ,offshore platform ,Deep water ,Attitude ,13. Climate action ,Facility Design and Construction ,Submarine pipeline ,business - Abstract
This paper describes a group model building activity designed to elicit the potential effects a projected multi-use deep water offshore platform may have on its local environment, including ecological and socio-economic issues. As such a platform is proposed for construction around the island of Hsiao-Liu-Chiu, Taiwan, we organized several meetings with the local stakeholders and structured the debates using group modeling methods to promote consensus. During the process, the participants iteratively built and revised a causal-loop diagram that summarizes their opinions. Overall, local stakeholders concluded that a multi-use deep water offshore marine platform might have beneficial effects for Hsiao-Liu-Chiu because more tourists and fish could be attracted by the structure, but they also raised some potential problems regarding the law in Taiwan and the design of the offshore platform, especially its resistance to extreme weather. We report the method used and the main results and insights gained during the process.
- Published
- 2018
19. Drilling platforms as artificial reefs: distribution of macrobenthic assemblages of the ?Paguro? wreck (northern Adriatic Sea)
- Author
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Marco Abbiati, Massimo Ponti, Victor Ugo Ceccherelli, Ponti M., Abbiati M., and Ceccherelli V.U.
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Ecology ,Fauna ,Artificial reef ,Offshore platform ,Aquatic Science ,Oceanography ,Fishery ,Northern Adriatic Sea ,Habitat ,Benthic zone ,Species evenness ,Submarine pipeline ,Species richness ,Benthic fauna ,Offshore drilling ,Ecology, Evolution, Behavior and Systematics ,Geology ,Decommissioning - Abstract
Offshore drilling raises the issue of disposal of platforms at the end of their productive cycle and re-use as artificial reefs has been proposed. The wreck of the "Paguro" drilling platform, which sank in the northern Adriatic Sea in 1965, offers the opportunity to study the performance of offshore structures as artificial reefs in a region where this solution has not been explored before. We provide a description of the macrobenthic assemblages present at the wreck at different sites and at different depths, based on destructive and photographic sampling. Results show that the wreck has been colonized by a rich and diversified fauna. Primary space has been dominated by mussels and oysters, which provide suitable habitats for a variety of benthic invertebrates. Assemblages vary among sites, species richness is greatest at those sites facing prevailing currents. Distribution patterns vary vertically, evenness (Hill's N10) decreasing significantly with depth. It is argued that the results contribute to the background knowledge required in rigs-to-reefs programmes. © 2002 International Council for the Exploration of the Sea. Published by Elsevier Science Ltd. All rights reserved.
- Published
- 2002
20. Incremental wave analysis and its application to performance-based assessment of jacket platforms
- Author
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Tore Holmas, A A Golafshani, Hossein Ebrahimian, Vahid Bagheri, Golafshani, A. A., Bagheri, V., EBRAHIMIAN CHELEH KHANEH, Hossein, and Holmas, T.
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Performance based assessment ,Engineering ,Environmental wave loading ,business.industry ,Metals and Alloys ,Offshore platform ,Building and Construction ,Variation (game tree) ,Structural engineering ,Collapse Wave Height ,Nonlinear system ,Mechanics of Materials ,Wave loading ,Limit (music) ,Wave height ,Submarine pipeline ,Limit state design ,Pushover analysi ,business ,Civil and Structural Engineering ,Incremental Wave Analysis (IWA) ,Static and dynamic nonlinear analyses - Abstract
In this paper, a relatively novel approach is established to estimate different limit states and accurate behavior of jacket platforms against environmental wave loading. This novel approach which is called Incremental Wave Analysis (IWA) can be an appropriate substitute to current pushover practice. The IWA can take into account the effects of variation in wave height and wave-in-deck loading in the estimating of platforms' behavior. This paper aims to introduce the applications of this approach in deterministic assessment of offshore platforms, comprehensively. The IWA can estimate the collapse-prevention limit state of jacket platforms properly. In addition, an appropriate parameter for ultimate capacity of offshore platforms is introduced which is called Collapse Wave Height (CWH). It is illustrated that the CWH can be utilized as a substitute to RSR parameter in the design and assessment of jacket platforms. Moreover, this novel indicator is able to exceptionally estimate the collapse probability of offshore platforms utilizing a deterministic practice. This is a unique feature that can never be achieved by current pushover method utilizing RSR parameter. The IWA can be carried out using either nonlinear static or dynamic wave analyses. Therefore, in this paper, both Static and Dynamic Incremental Wave Analyses (SIWA and DIWA) will be systematically explained. Before conducting DIWA, some fundamental questions such as importance of dynamic analysis and also proper methodology for conducting dynamic analysis, will be investigated. Comparison between SIWA and DIWA will also bring about worthwhile results which will be discussed thoroughly.
- Published
- 2011
21. Risk assessment based on performantial criterion for inspection of offshore structures in presence of large cracks
- Author
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Franck Schoefs, Mustapha Rguig, Alexandre Clément, Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Risk analysis ,fissure traversante ,Engineering ,0211 other engineering and technologies ,020101 civil engineering ,02 engineering and technology ,0201 civil engineering ,[SPI.MAT]Engineering Sciences [physics]/Materials ,through crack ,Limit state design ,Limit (mathematics) ,inspection ,Randomness ,risk assessement ,General Environmental Science ,021110 strategic, defence & security studies ,business.industry ,Structural engineering ,[SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph] ,offshore platform ,plateforme offshore ,General Earth and Planetary Sciences ,Submarine pipeline ,business ,Risk assessment ,évaluation des risques - Abstract
International audience; When performing risk analysis, it is often uneasy to find the link between limit state and consequences. This paper focuses on efficiency based limit states in case of large cracks on offshore structures. Randomness and uncertainties on loading as well as on crack measurement and detection are introduced.; Les analyses de risque sont souvent délicates par manque de lien direct entre la fonction d’état et les conséquences. Cet article propose des fonctions d’état de type performantiel (déplacement) dans le cas d’apparitions de fissures traversantes dans des tubes métalliques de structures offshore. Les aléas sur le chargement, la mesure de la fissure et la performance des inspections sont intégrés dans l’analyse de risque.
- Published
- 2006
22. Vertical pullout capacity of model batter anchor piles in marine clays
- Author
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S. Narasimha Rao and C. Veeresh
- Subjects
pullout test ,Engineering ,Fluid structure interaction ,Friction ,Batter anchor piles ,Water wave effects ,Ocean Engineering ,Structural analysis ,Vertical pullout capacity ,Wind stress ,Oceanography ,Skin friction ,offshore platforms ,Shear strength (soil) ,Parasitic drag ,Anchorages (foundations) ,Wave pressure ,Geotechnical engineering ,Model structures ,soft clay ,Marine clayey beds ,Embedment ,business.industry ,anchor ,Structural engineering ,clay ,Geotechnical Engineering and Engineering Geology ,offshore platform ,Wind engineering ,Uplift pressure ,Pile foundations ,Submarine pipeline ,business ,Pile ,Offshore structures ,pile - Abstract
Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. For foundations in such structures, usually a combination of vertical and batter piles is used. Little information is available in the literature about estimating the capacity of piles under uplift. In cases where these supporting piles are not vertical, the behavior under vertical pullout is not well established. In this article the vertical pullout behavior of batter piles is examined through an experimental investigation carried out on model batter anchor piles. The tests are conducted on model aluminum pipe piles of 19 mm diameter with different embedment ratios in a soft marine clayey bed at different consistencies and with various batter angles of 0�, 10�, 20�, and 30�. Results indicate that the pullout capacity of a batter pile is less than that of a vertical pile. This reduction is explained in terms of reduced area available for skin friction. Based on this, pullout behavior of batter anchor piles is described as "short anchor" and "long anchor" failures. However, with increase in the embedment length, the capacity of batter pile remains unaffected.
- Published
- 1996
23. Subsidence monitoring of offshore platforms
- Author
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Feng Sheng, Yue Qianjin, Wang Yanlin, Ma Yingxin, and Bi Xiangjun
- Subjects
Engineering ,business.industry ,Strain measurement ,Subsidence ,General Medicine ,FBG strain sensors ,Compression (physics) ,offshore platform ,Subsidence monitoring ,diffinetial settlement ,Geotechnical engineering ,Submarine pipeline ,Monitoring methods ,business ,Engineering(all) - Abstract
The normal subsidence monitoring technologies, used in civil engineering, are hard to apply in ocean engineering. Because it is hard to find a fixed reference for subsidence monitoring. A new method, which is suitable for subsidence monitoring of offshore platforms, is proposed in this paper. Firstly, the compression characteristic of the soil was analyzed and the harms of subsidence are discussed. Based on the analysis, the subsidence monitoring method was given. Finally, an real application is shown. Some advanced measurement technologies, such as the FBG strain measurement techniques and so on, were used in this application. The real application indicates that the new method is suitable for the subsidence monitoring of offshore platforms.
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