Day 2 Tue, November 06, 2018最新文献

{"title":"Full Scale Trials for the Validation of Ship Performance and Model Tests in Ice","authors":"N. Reimer, Q. Hisette, C. Schroeder","doi":"10.4043/29155-ms","DOIUrl":"https://doi.org/10.4043/29155-ms","url":null,"abstract":"\u0000 The paper addresses methods used to analyse full scale trials for performance determination of ships in ice. Furthermore uncertainties resulting from assumptions taken in the early stage when ice model tests are typically performed are discussed. In a first step the difference between model test based prediction and final determined performance from ice trial are shown for an example ship for which both results are available. The main assumptions are critically reviewed and possible reasons for deviations between the prediction and final outcome of ice trials are systematically assessed. The performance of ships in ice determined by model testing based on single combinations of speed and ice thickness is compared to full scale trial results. Furthermore the effect of generalizing impact friction and snow cover which is usually generalized for the model based prediction is determined by different methods. Finally a comparison between the propeller-ice interaction based on model tests and full scale trials is made to assess possible sources and magnitude of deviations between the performance prediction in early design stage and the final trial results.\u0000 The paper shows that even though the prediction of icebreaking resistance by theoretic means and by model testing is well established comparisons between performance results obtained from ice trials sometimes deviate in their values and trends from those predictions. Besides testing uncertainties also missing parameters and testing methods can be identified as reasons for differences in the results. Recorded time series of propeller ice interaction in full scale and model scale are compared and analyzed. Different scaling approaches are applied to the model scale torque trends and compared to the full scale data. The results of the comparison between full scale and model test results show the limits of the current methods and encourage to take a closer look at additional parameters with stronger influence on ice performance. Additionally the comparisons of ship performance and propeller ice interaction of model and full scale data will improve the understanding of the transferability from model to full scale data.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129827324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Iceberg Risk to Marginal Field Developments: Physical Tests to Investigate Free-Floating Iceberg Contact with Pipeline Laid on the Seabed","authors":"E. Bailey, R. Phillips","doi":"10.4043/29097-ms","DOIUrl":"https://doi.org/10.4043/29097-ms","url":null,"abstract":"\u0000 Up to present, the annual iceberg contact frequency for short subsea flowline systems designed for offshore Newfoundland and Labrador has been less than the target reliability level. For longer flowlines, iceberg contact rates will be higher and the consequence of such contacts must be considered. It is possible, for example, that the pipe gets pushed into the seabed with acceptable damage to the pipe and/or localized ice failure takes place. If it can be demonstrated that a pipe could survive some impacts, it might be possible to avoid costly protection strategies such as trenching or rock berms. This paper describes physical tests conducted as part of a preliminary investigation to assess the consequence of a free-floating iceberg interacting with a flowline placed on the seafloor. Two scenarios were considered in this testing program. The first focused on understanding the local iceberg failure processes and the second evaluated the transverse flowline motion when a free-floating keel snags a flexible pipe laid on the seabed.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124808913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite Element Analysis of Flexible Pipe Tension Loads Due to Iceberg Interaction","authors":"Kenton Pike, Andrew Blundon","doi":"10.4043/29126-MS","DOIUrl":"https://doi.org/10.4043/29126-MS","url":null,"abstract":"\u0000 Offshore Newfoundland and Labrador, Canada, development costs associated with iceberg protection pose significant challenges in terms of project execution and economics for marginal field subsea tie-backs. The current standard practice is to assume that if an iceberg makes contact with a subsea flowline, the flowline is dragged indefinitely imparting significant load to the connections at each end. To isolate flowlines from downstream and upstream assets, weak links are installed in the flowline that are designed to separate once a specified level of tension is reached. This prevents damage to wellheads and other subsea equipment and eliminates the possibility of uncontrolled hydrocarbon release. However, the weak links are very costly and possess inherent risk of failure, which can lead to an uncontrolled release of hydrocarbons. This paper addresses the requirement of weak links by analyzing the flowline tensions transmitted due to iceberg-flowline-soil interaction events.\u0000 The assumption that an iceberg drags a flowline indefinetly imparting significant tension on the end connections can be challenged. This paper seeks to estimate the tension loads developed in an untrenched flexible flowline due to interaction with free-floating and gouging icebergs. Large deformation finite element analysis is utilized to simulate the iceberg-flowline-soil interaction scenario. The iceberg keel is idealized with shape and dimensions based on analysis of recent iceberg profiles. A sensitivity study is conducted to assess the influence of keel size, gouge width and depth on flowline tension developed throughout the flowline resting on very dense sand. The sand constitutive behavior is modelled using a user subroutine accounting for the effects of mean effective stress and relative density on the soil strength and volumetric response.\u0000 The ice-flowline-soil interaction mechanisms are detailed for free-floating and gouging interaction events. During interaction with free-floating icebergs, the flowline is typically depressed into the seabed, and the keel rides over the flowline. The gouging interaction scenario simulates the complex interaction between the frontal soil mound developed during the gouging process and the untrenched flowline.\u0000 This paper provides new insight into the iceberg-flowline-soil interaction scenario that has not been examined previously. Based on the analysis results presented, an alternative strategy to mitigate tension transfer to downstream and upstream assets is discussed.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115756699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Protection of Subsea Assets Using an Iceberg Protection Structure","authors":"Andrew Blundon, T. King","doi":"10.4043/29158-MS","DOIUrl":"https://doi.org/10.4043/29158-MS","url":null,"abstract":"\u0000 For oil and gas projects offshore Newfoundland, Canada, subsea structures are generally placed in excavated drill centres which lower the equipment below the natural mudline, protecting the equipment from damage due to iceberg impact. This paper introduces a concept of protecting this equipment by utilizing a concrete structure affixed to the seabed using hammer driven piles.\u0000 Iceberg loads have been assessed utilizing a Monte Carlo iceberg contact model and a modified version of the Iceberg Load Software (ILS) developed for regions offshore eastern Canada. The Subsea Iceberg Protection Structure (SIPS) was designed using post-tensioned concrete construction. Preliminary concrete design in addition to pile capacity design is performed utilizing FE analysis. Using a hammer driven piled system, the maximum lateral resistance capacity can be determined in addition to the maximum impact energy absorption.\u0000 The internal Subsea Production System (SPS) system has been designed to specifically fit inside the SIPS while maintaining full ROV access for operation, maintenance and future well intervention.\u0000 The SIPS was designed as an L1 structure in accordance with ISO 19906. This includes impact from free floating and gouging icebergs. The design load for this impact event was calculated based on energy absorbed through ice crushing. The deformation and global movement of the SIPS was not considered as part of the energy absorption mechanism. The maximum ice crushing design load on the SIPS was determined for four locations on the Grand Banks offshore Eastern Canada.\u0000 In addition to the structural design of the SIPS, the piling system was analysed to determine the maximum capacity. The total lateral resistance was determined using a combination of a continuum model and a structural beam model (P-y method). The global movement was less than the maximum allowable deformation of the structure. The structure is therefore considered fit for purpose.\u0000 The projected construction and installation cost of this structure shows the potential for reduced costs compared to an excavated drill centre, thereby increasing the feasibility of potential tie-backs.\u0000 Using updated knowledge regarding iceberg size and geometry, areal density and ice strength, the analysis and design presented in this paper suggests that it may be more economical to install protection structures rather than dredge excavated drill centres, for marginal fields. In addition, the advancement of the internal SPS system is such that the equipment footprint is compact, requiring limited space within the SIPS.\u0000 This paper provides the necessary information to show that installing a structure to protect subsea equipment is technically achievable.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126025554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Nearshore Class Unmanned Surface Vehicles: The Last-Mile Solution for Arctic Littoral-Zone Surveys","authors":"Helen Stewart, Rada Khadjinova, K. Brumley, S. Earl, Alex Waugh, Nick Thomas, Bob Waugh, D. Rycroft","doi":"10.4043/29150-MS","DOIUrl":"https://doi.org/10.4043/29150-MS","url":null,"abstract":"\u0000 Challenges and complications of hydrographic and marine surveys in the last mile between sea and shore are compounded in the Arctic by remoteness, lack of infrastructure facilities, difficult transport, and environmental hazards. Without safe, cost-effective, and technologically fit-for-purpose survey solutions, these last-mile surveys are often neglected or inadequate for their design purposes. These special challenges pose similar difficulties to littoral marine and freshwater surveys in temperate New Zealand. To meet these challenges, experienced surveyors from the New Zealand branch of a global survey company partnered with a New Zealand-based naval architect to design and build a seaworthy class unmanned surface vehicle (USVs) for work in remote and isolated environments. The new nearshore class USV is easy to transport by any commercial means, inexpensive, safe for a two-person crew to operate, and has a customizable payload with large capacity for its size.\u0000 The ability to work safely in harsh, remote environments at a reasonable cost make the new nearshore class USV an attractive and cost-effective option for surveying in the Arctic. This paper presents information on this survey solution and discusses advantages to USVs as a survey platform in Arctic environments.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"194 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123334582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of an Iceberg Impact Load Assessment Tool","authors":"Paul Stuckey, Yujian Huang, Mark Fuglem","doi":"10.4043/29091-MS","DOIUrl":"https://doi.org/10.4043/29091-MS","url":null,"abstract":"\u0000 Icebergs can pose risks to platforms in arctic and subarctic regions. These risks require careful consideration during design, and as well during operations. Platforms must be designed to withstand potential impacts from icebergs, or to disconnect and move offsite to avoid impacts. ISO 19906 allows use of ice management to mitigate iceberg and sea-ice actions. In the case of icebergs, management may include detection, monitoring, towing, disconnection and evacuation. Threat assessment is also a critical input to the iceberg management decision-making process. For example, given one or more detected icebergs and available information on the iceberg and environment characteristics, what is the probability of exceeding platform design ice actions? Based on the threat assessment, better decisions can be made regarding which iceberg to manage, whether more information should be acquired, and whether shut-down or evacuation is needed.\u0000 This paper describes a new tool developed to estimate the distribution of iceberg impact actions from an encroaching iceberg given concurrent metocean conditions, conditional on impact. The tool can be used in a number of ways depending on the information available to the user. It can be used to assess the threat from a single iceberg or can be used to compare actions from multiple icebergs in the region, or for the same iceberg but with changing weather conditions. The iceberg load assessment tool is demonstrated for several example cases on the Grand Banks, showing the benefit of improved iceberg characterization obtained through rapid iceberg profiling.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133446530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Model Tests of the United States Coast Guard Heavy Polar Icebreaker Indicative Designs","authors":"Jungyong Wang, A. Akinturk, Jeffrey Brown, Caroline Muselet, J. Millan","doi":"10.4043/29106-MS","DOIUrl":"https://doi.org/10.4043/29106-MS","url":null,"abstract":"\u0000 This paper describes the results of model tests carried out in ice and open water conditions to evaluate performance of the United States Coast Guard (USCG) Heavy Polar Icebreaker (HPIB) indicative design. The resistance, propulsion and manoeuvring performance in ice conditions was evaluated at three different ice thicknesses (4, 6 and 8 ft.) with flexural strength 100 psi using two power setups, 36500 HP and 65000 HP. Calm water resistance and propulsion tests were also performed to evaluate open water performance. Models were constructed and tested corresponding to two indicative designs, one with triple shaft propulsion system and the other with one centre shaft and two wing podded propulsors. The present paper describes only the results for the model with triple shaft propulsion system.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124154351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DP in Ice Environment – Improving Safety and Efficiency of Arctic Operations: An Update","authors":"Mohammed Islam, Jason Mills, R. Gash, Wayne Pearson, J. Millan","doi":"10.4043/29177-MS","DOIUrl":"https://doi.org/10.4043/29177-MS","url":null,"abstract":"\u0000 The objective of this paper is to present an update of various research activities of a multi-year research and development project aiming at developing dynamic positioning (DP) system technologies specifically for ice-rich environments. Since the beginning of the project in 2014, significant progress has been made in various activities that aimed at achieving the primary project objective of improving the safety and efficiency of oil and gas operations in ice infested environments through the enhancement of existing DP system technologies for efficient operations and training of DP operators in simulated realistic ice environments by providing necessary exposure to DP operations in ice. Prototypes of multiple vessel models, ice force models, and other environmental force models have been developed and are being validated. A modularized simulation and validation platform has been developed for the integration, validation, testing of all these prototypes. The research team at the National Research Council's Ocean Coastal and River Engineering (NRC-OCRE) is on the verge of delivering the complete package of the simulation platform to the project lead, the Centre for Marine Simulation (CMS) at the Fisheries and Marine Institute (MI) of Memorial University of Newfoundland, for comprehensive checking and testing of the platform by the project commercial partner Kongsberg Digital Simulation (KDS) Ltd.\u0000 In this article, an update on various activities regarding the physical model testing, numerical modeling and development of simulation platform is presented. Various modules of the prototype validation platform and their integration are discussed along with their current development status. A brief discussion on various components of the ice force modeling approach, the algorithms and implementation strategies is provided. Finally, the initial results of a number of DP in ice simulation cases and comparison with validation data is presented. A brief outline of the work remaining to be completed for achieving the project objectives, along with the associated limitations are also provided.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133842146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trends in Expedition Vessels in Polar Waters","authors":"J. Salminen, Maximilian Vocke","doi":"10.4043/29123-MS","DOIUrl":"https://doi.org/10.4043/29123-MS","url":null,"abstract":"\u0000 This paper will study the latest development of the expedition cruise market from lower ice class to latest heavy icebreaker class cruise ships. Expedition cruise industry is growing at the moment quite fast. New designs coming in to the market. Ice classes varies from PC6 to PC2.\u0000 The paper will describe current order book for expedition cruise vessels. Aker Arctic developed concept design together with Ponant and Stirling Design International for completely new type of expedition cruise vessel. The Ponant Icebreaker is a heavy PC2 class icebreaking cruise vessel designed to be a world's first truly luxury icebreaking cruise vessel capable to taking passenger to the North Pole. In the paper we will describe what kind of methods were used when selecting the design criteria when operating in extremely harsh environment.\u0000 When jumping from PC6 class to PC2 class it is a whole different game, several things must be taking in to account. Environmental impact is also important when designing vessels for fragile Polar environment and selecting the right systems in design phase is important. Passenger safety and comfort is very important. Taking the rules like of the Polar Code and Safe Return to Port rule causes some challenges when designing vessel for high Polar waters. Novel/Additive Information: Designing new type of vessel, which doesn't exist in the market is challenging. New ideas and solutions needs to be evaluated carefully. Selecting the best solutions is an utmost important.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123993153","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Propulsion System Ice Load Measurements Onboard IB Polaris","authors":"Pirjo Maattanen, S. Hanninen, T. Heideman","doi":"10.4043/29119-MS","DOIUrl":"https://doi.org/10.4043/29119-MS","url":null,"abstract":"\u0000 This paper presents operational experience and ice measurement results from Finnish Icebreaker Polaris propulsion system. Icebreaker Polaris applies a novel three propulsion unit concept. During the shipbuilding period an extensive ice load measurement system was installed on two of the Azipod units. The paper will present key findings from the measurements from the winter periods 2017-2018.\u0000 The target of the ice load measurement campaign is to increase the designer knowledge of propulsor ice loads in different ship operations. The purpose is to understand in more detail the load distribution for component life estimations and clarify differences between bow and stern propulsor ice loads and frequencies. Due to non-linear load distribution in propulsor at extreme loads, strain gauges were installed at two levels in propulsor hull.\u0000 This paper will highlight some measurement results of propulsion system behavior during the ice trials and long term measurements from the winters 2017 and 2018. The full-scale ice operation data collected in the Baltic Sea ice conditions can be further utilized in a development vessel and its propulsion system of heavy polar icebreaker type.\u0000 The measurement campaign onboard the Polaris is planned to continue during coming winters. The aim is to collect statistical ice load data to improve the understanding of the fatigue and ultimate design loads. One of the goals is also to clarify how much load the bow mounted propulsion unit will experience compared to the stern units. Based on the measurement results so far, we can conclude that icebreaker with bow mounted Azipod propulsor can be operated without limitations in all ice conditions, just like all the other icebreakers in the Baltic.","PeriodicalId":286074,"journal":{"name":"Day 2 Tue, November 06, 2018","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127666328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}