{"title":"Life-Cycle Assessment and Costing of Alternative Fuels and Emission Reduction Technologies","authors":"N. Ventikos, P. Sotiralis, Manolis Annetis","doi":"10.5957/some-2023-016","DOIUrl":"https://doi.org/10.5957/some-2023-016","url":null,"abstract":"Decarbonisation in maritime industry can be possible by considering renewable sources of energy or various novel technologies for improving the environmental footprint. The established strategy and the respective regulatory framework are pushing hard towards this direction, while the European Union (EU) introduces regulations and initiatives to accelerate the transition. Each decarbonisation effort should be closely examined both in terms of emissions and cost in order to prove its benefits to the environment and ship owner, respectively. Uncertainties should be carefully considered, especially when it comes to carbon pricing and fuel prices. This paper lays the path towards life-cycle assessment and costing for alternative fuels and emission reduction technologies, while an indicative case study is qualitatively considered.","PeriodicalId":382692,"journal":{"name":"Day 1 Tue, March 07, 2023","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124346474","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":"A Control-Oriented Lumped Parameter Drillstring Dynamic Model for Real-Time Vibration Mitigation and Drilling Optimization","authors":"Yifan Zhang, P. Ashok, Dongmei Chen, E. van Oort","doi":"10.2118/212453-ms","DOIUrl":"https://doi.org/10.2118/212453-ms","url":null,"abstract":"\u0000 Drilling is an essential operation for subsurface hydrocarbon/geothermal energy extraction or underground waste fluid/gas storage. Efficient drilling is the key to an economically viable operation. Axial, torsional, and lateral oscillations that are excited in the drillstring by various surface/downhole sources (like the application of the weight-on-bit (WOB), rock cutting process, bottom-hole-assembly (BHA) resonance, downhole tool operation, drilling fluid dynamics, etc.), are the prime causes of downhole tool failure, material fatigue, bit wear/damage, and insufficient surface-to-bottom energy transfer. Since the 1960s, a wide variety of models have been developed to analyze drillstring dynamics and optimize the well/drillstring design. With the advance of drilling engineering, sensor technology, and data science, a fast and comprehensive drilling system dynamic model is in need for real-time drilling optimization and automation.\u0000 In this study, a control-oriented physics-based lumped parameter model (LPM) is developed to investigate the fully coupled drillstring dynamics in all three directions. Various boundary conditions (wellbore-drillstring interaction, bit-rock interaction, presence of stabilizers/centralizers) and system input actuations (surface WOB/hookload, surface rotational speed (RPM)/torque, mud motor operational parameters, etc.) are defined in the modeling framework. Simulations are run for different drillstring scenarios in a vertical and an actual L-shaped wellbore configuration. System dynamic responses illustrate various amplitudes, frequencies, and modes of fully coupled drillstring vibrations at different depths when simulated with different drilling parameters. Another significant observation is the emergence, propagation, and transition of lateral vibration modes between forward, backward, and chaotic whirl patterns. Based on the tradeoff between accuracy and complexity, the proposed dynamic model can be adapted for real-time model-based control, and can also be deployed for well design purposes or digital twinning applications.","PeriodicalId":382692,"journal":{"name":"Day 1 Tue, March 07, 2023","volume":" 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113949760","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}
Vasileios Kostoulas, George Pontikakos, Ioannis Sklias, A. Karvountzis-Kontakiotis, L. Kaiktsis
{"title":"Modeling intermediate and alternative fuel emissions in large two-stroke engines: Towards an accurate assessment of decarbonization impact","authors":"Vasileios Kostoulas, George Pontikakos, Ioannis Sklias, A. Karvountzis-Kontakiotis, L. Kaiktsis","doi":"10.5957/some-2023-037","DOIUrl":"https://doi.org/10.5957/some-2023-037","url":null,"abstract":"A range of non-conventional fuels are currently being considered for reducing greenhouse gas emissions from shipping. Modeling the emissions profile of these fuels can support the rapid development of engine concepts that assist decarbonization efforts. The goal of this study is to develop and test effective thermodynamic modeling frameworks which can predict (a) methane emissions from natural gas-operated engines, and (b) greenhouse gas and air pollutant emissions from ammonia-operated engines. The GT-Suite 0D/1D-CFD simulation software is used as the main framework for model development. Modeled emissions show generally good agreement with experimental measurements from large engines operated with Liquefied Natural Gas or diesel-ammonia mixtures.","PeriodicalId":382692,"journal":{"name":"Day 1 Tue, March 07, 2023","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133240588","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}