bluuebunny/crossref_metadata_2025_split huggingface dataset:
HSVA Model Ice – A Status Report
Authors: Ziemer Gesa , Stange Timo , Hisette Quentin 
Published: October 2022

Abstract
The development of HSVA’s current standard model ice dates back to 1993 when Evers and Jochmann introduced a new production process [1]. Since that time, a lot of experience has been gained in numerous ice sheets, regarding both, the process of production itself and the properties of the resulting model ice. Meanwhile, requirements on ice model tests, and also on the model ice itself, have changed during the past decades. This relates to more diversified test types, which do not only concentrate on ice-breaking ship designs with typical flat bows, but also on a variety of structures and hull designs that include different failure modes. Also, the typical property range of model ice regarding strength and thickness has significantly widened. This paper summarizes the changes that have been made over the years, leading to the standard model ice that is available at HSVA today. Its properties are presented and discussed, showing limitations regarding absolute property values and their uncertainty, as well as the ability for correct representation of specific interaction scenarios. Further, methods to modify the model ice for different specific test scenarios are suggested and discussed. This includes for instance global and local crushing against vertical structures.
Assessment of Uncertainty in Sea Ice Charts and Its Impact on Operational Planning in the Kara Sea Region
Authors: Panchi Nabil , Verma Uttam , Kim Ekaterina , Hughes Nick , Bhattacharyya Anirban 
Published: October 2022

Abstract
Ice charts play an important role in the planning of marine operations, including navigational guidance among other use cases (e.g., climate monitoring and model validation). With a growing number of vessels operating in dynamic sea ice cover and considering the November 2021 events when several ships were stuck and delayed in the Arctic waters, it becomes ever more important to have accurate and timely ice information as well as to account for the underlying uncertainties in the sea ice products. To this end, the present study evaluates the variability in estimated total sea ice concentration in ice charts of the Russian Arctic and Antarctic Research Institute (AARI) and the Norwegian Meteorological Institute (MET Norway). The weekly ice charts from AARI were compared with several daily charts from MET Norway for the corresponding week to discover any discrepancies in the reported sea ice concentration. Preliminary results of this study indicate seasonal as well as spatial trends in the absolute difference in total ice concentration between the two sea ice products. A higher difference in concentrations was observed in the western and the central regions of the Kara Sea which see a lot of ship traffic. Sensitivity of the results to the comparison approach is conducted and the found discrepancies between the two ice products are placed in the context of operational route planning.
A Hybrid Time-Frequency Domain Approach for Estimating Mooring Lines Dynamic Response
Authors: Leivas Simão Marina , Queija de Siqueira Marcos , Gonçalves de Lacerda Thiago Ângelo , Videiro Paulo Maurício , Sudati Sagrilo Luis Volnei 
Published: October 2022

Abstract
It is known that, for a given short-term environmental condition, mooring lines fatigue damage assessment can be made from the tension cycles counting using a sufficiently long tension time series. This can be obtained through coupled floater-lines time domain analyses where lines are modeled with the catenary equation, leading to faster simulations but also to quasi-static line responses that do not take line dynamics into account. On the other hand, a coupled floater-lines analysis where the lines are modeled with finite elements (FE) can assess line dynamics effects since it considers dynamic amplifications of the system in the wave frequency range. Such dynamic effects can greatly impact fatigue damage calculations and should be considered. However, while more accurate, coupled FEA-based models can become very expensive in time and computer resources when the number of environmental conditions to be evaluated is high. In this context, an approximate and efficient hybrid solution was developed for the assessment of dynamic tension series, taking advantage of quasi-static coupled analyses. In the solution, it is assumed that the line dynamic response can be roughly estimated in the frequency domain from linearized tension transfer functions for the segment of interest and from motion series at the floater-line connection point, obtained with previous quasi-static analyses. The linearized tension transfer functions are previously obtained by applying unitary amplitude motions in the line axial direction at the top connection point for different excitation frequencies and also for different line pretension levels. The methodology is validated for a spread-moored FPSO installed in Brazilian deep waters. When compared to complete FEA-based dynamic analyses, it is shown that the simplified solution provides good estimates for the lines dynamic tension response and can be a powerful tool to save computer time in fatigue damage assessments.
Investigation on Fiber Assisted Multistage Fracturing of Horizontal Well in Tight Low Permeability Sandstone Reservoirs
Authors: Zhang Lufeng 
Published: October 2022

Abstract
Tight sandstone reservoirs, widely distributed in the world, are the important oil and gas exploration and exploitation area in the future and have a favorable development prospect. Multistage fracturing of horizontal well is a necessary technology to inspiring the production potential and enable commercial productivity for tight reservoirs. Due to the multiple functions, degradable fiber is widely applied during hydraulic fracturing. On the one hand, fiber can enhance the sand patch profile when it was injected into the fracture with the carrier fluid; On the other hand, fiber aggregation can accelerate the formation of temporary plugging agent, which is conducive to the uniform propagation of fractures. In this paper, we conducted a series of experiments to evaluate the properties of fiber in detail. Moreover, the pilot application of fiber which was injected during the whole hydraulic fracturing was also carried out. The laboratory evaluation experiments mainly achieved the following findings: 1. The length, diameter and density of fibers are approximately 6mm, 10μm and 1.24 g/cm3, respectively. 2. The fiber can be well dispersed in high viscosity slick water with almost no settlement. 3. Under high closure pressure, the conductivity of fiber and proppant mixture is higher than that of pure proppant. Furthermore, the field case shows that the fiber assisted fracturing makes the permeability-challenged formations economically recoverable, which deepens the understanding the effect of fibers and provides fundamental for field treatment design.
Data-Driven Propeller and Rudder Modeling for Maneuvering Analysis of the ONR Tumblehome
Authors: Knight Bradford G. , Silva Kevin M. , Maki Kevin J. 
Published: October 2022

Abstract
The accurate prediction of ship maneuvering characteristics requires accurate representation of the forces on the propellers and rudders. Computational Fluid Dynamics (CFD) can accurately predict the maneuvering characteristics of a vessel, but the expense is dominated by the discretization of the propellers, and long-time simulations are too expensive for practical use. Propeller and rudder models can reduce the computational cost, but can also reduce the accuracy. The objective of this work is to accurately model the Office of Naval Research (ONR) Tumblehome performing both turning circle and zig-zag maneuvers with high-fidelity data-driven propeller and rudder models. The use of the data-driven propeller and rudder models significantly reduces the computational cost of performing a maneuver. The forces of the propeller and rudder are calculated as a function of the propeller revolution rate, the rigid body velocity of the vessel, and the rudder angle. The propeller and rudder models are trained with a select number of CFD simulations with the discretized propeller and rudder operating in the behind condition. The propeller and rudder models maintain the accuracy of using a discretized propeller and rudder with respect to CFD simulations used for validation. The models calculate the multi-degree of freedom force acting on the propellers and rudders of the vessel. For comparison, the maneuvering characteristics of the vessel are also analyzed with a simplified body-force propeller and a Whicker and Fehlner rudder model.
Numerical Simulation of Dynamic and Static Mechanical Response of Sinusoidal Sandwich Structure
Authors: Yao Houqi , Qu Jia 
Published: October 2022

Abstract
Based on the design characteristics of corrugated sandwich structure and pyramid lattice sandwich structure, this paper proposes a sinusoidal beam sandwich structure with different amplitude-period ratio, curved beam cross-sectional area and cross-section adjacent side length ratio. Three variables were used to analyze the quasi-static compression performance and impact resistance of different variable structures by numerical simulation. The three-dimensional modeling of the sinusoidal beam sandwich structure is briefly introduced, and the relative density calculation formula is derived based on the theory of mechanical characterization of the sandwich structure. Using Abaqus/Standard for quasi-static compression numerical simulation, the deformation process and failure modes of the sinusoidal beam sandwich structure under quasi-static compression are mainly presented as the bending of the two beams and the plastic hinge expansion at the peaks and valleys. The influence of the cross-sectional area and the length of the adjacent side of the curved beam on the anti-pressure performance is greater than that of the curved beam amplitude-period ratio. Using Abaqus/Explicit to simulate the SHPB impact test of the sinusoidal beam sandwich structure, it is concluded that the impact resistance of the sinusoidal beam sandwich structure is approximately irrelevant to the strain rate, and the amount between the transmitted wave and the incident wave occurs. The reduction in grades reflects excellent impact and flameproof properties and good energy absorption characteristics.
Sensitivity Analysis of a Corrosion Prediction Model Using Monte Carlo Simulation
Authors: Santos Stephane S. M. , Souza Gilberto F. M. , Barros Leonardo Oliveira de , Orlowski Rene Thiago Capelari , Martins Marcelo R. , Schleder Adriana M. 
Published: October 2022

Abstract
Obtaining a realistic prediction of the corrosion rate of equipment employed in the oil and gas industry is vital for safe operations. During the last few years, several corrosion prediction models have been and are being developed by oil companies and research institutes. The corrosion prediction models are usually made to meet a specific type of corrosion scenario, such as corrosion in the presence of H2S, corrosion in the presence of organic acid, corrosion in the presence of CO2, among others. Because of the distinct philosophies of these models, different results can be obtained for the same cases. The corrosion rates predicted by different models have a great influence on the selection of materials, definition of inspection plans, among other important decisions; therefore, on the total cost of the project. Reliable predictions of the corrosion rate are vital to controlling the degradation, ensuring the integrity of the operation at an optimized cost. This paper presents partial results of a research project that aims to evaluate the variability of corrosion rate prediction obtained by applying different corrosion models. This information could support oil and gas companies in selecting the most suitable model for carrying out the expected corrosion rate in new installation projects, considering the expected operational condition. In this paper, a sensitivity analysis of the NORSOK corrosion prediction model, using Monte Carlo simulation, is presented. In order to perform the Sensitivity Analysis, a methodology composed of 4 phases was followed: Selection of parameters, Monte Carlo Simulations, Obtaining Corrosion Rates and Analysis. It was found that, for the analyzed cases, the parameters with the highest and lowest impact on the prediction of corrosion rates, respectively, were pH and total pressure.
A Comparison of Design Wave Methods for Flexible Fish Farms
Authors: Jansen Markus B. , Aspelund Leiv , Fristedt Tim , Skjulstad Christoffer 
Published: October 2022

Abstract
Conventional floating fish farms are deployed in increasingly larger arrays and in exposed locations with challenging environmental conditions. Hydrodynamic analysis of such structures requires models with numerous coupled flexible elements. Therefore, analysis with irregular sea states is usually considered impractical. Today, the established practice in the aquaculture industry is to approximate the irregular sea state with regular waves with the most probable largest wave height. Previous numerical work on single-cage fish farms has suggested that this method produces the appropriate design forces if the simulations are run for two wave periods plus one wave period ramp-up. In this paper, the results of an extensive numerical study on floating flexible fish farms of varying sizes from 1 × 1 to 8 × 2 cages exposed to environmental loads from 4 different directions are presented. The forces found using the industry-standard regular design-wave methodology are compared to forces based on their respective irregular sea states. A new alternative regular-wave method is also proposed and compared to the other approaches. The results show that the current industry-standard method often underpredicts the dimensioning forces in larger fish farms. The new method appears to be a significant improvement, but more refinement and testing is necessary before irregular simulations can be completely omitted.
Modeling of Thermo-Mechanical Behavior of Laser Powder Bed Fusion of Nickel-Based Super Alloy Parts Used in Oil and Gas Industry
Authors: Beiranvand Zeinab Malekshahi , Ratnayake R. M. Chandima , Rasoulinia Mehdi , Moradiani Amir 
Published: October 2022

Abstract
Nickel-based alloys are used for a broad range of applications in oil and gas (O&G) production and marine engineering because of their good corrosion resistance and mechanical properties. The future of laser AM in the O&G industries is highly promising due to the ability to deliver cheaper and better parts quickly. As it is in the initial stages, rigorous research needs to be done to enhance the fabrication speed and parametric optimization to improve the thermo-mechanical properties of the fabricated components by laser powder bed fusion AM. Simulation methods provide financially viable and the least resource-consuming approach for the qualification of produced parts, enabling metallurgical and mechanical characterization in a short time. In this research study, a three-dimensional finite element model is developed to predict the temperature, residual stress, and distortion in nickel-based super alloy parts fabricated by a multi-layer laser powder-bed fusion (LPBF) process, to analyze the thermal and residual stress distributions. For this purpose, a FEM model of LPBF was applied that includes a thermal model representing the scanning laser thermal input, a material model to define the temperature-dependent material property in the cyclic heating and cooling environment, and a physics-based method to describe the layer build-up process. For validation of the results, the experimental results were used, and the validation results were presented.
Small Size Steel Catenary Riser S-Lay Installation With Flexible Joint as 2nd End: Difficulties and Solutions
Authors: Liu Song , Du Yongjun , Yu Wentai 
Published: October 2022

Abstract
S-lay installation of a 6-inch small-sized SCR with flexible joint assembly in the 2nd end is investigated in this paper. Due to the huge difference in external dimensions, weights and bend stiffnesses between the riser pipe and the flexible joint, passing through the S-lay vessel stinger of the flexible joint assembly poses a big challenge to the strength integrity of the overbend section of the SCR, especially the steel pipe at the connection with the flexible joint body. This paper summarizes the engineering approach and FE analysis work that were carried out in order to reduce the maximum strain in the critical riser overbend section. These engineering approach options include design of a long tapered stress joint type shroud, an extended upper shroud, or an installation aid in large diameters, to facilitate installation of flexible joint assembly travelling along the stinger. The latter approach is selected for detailed design which lays the engineering groundwork for successful pre-laid operation of the 6-inch SCR with flexible joint.
Image Processing to Extract Ice Features to Aid Modelling of Ice Force
Authors: Akter Shamima , Islam Mohammed , Zaman Hasanat , Ahmed Salim , Imtiaz Syed , Gash Robert 
Published: October 2022

Abstract
Sea-ice observation and estimation of ice forces are becoming increasingly important with the increased activities in arctic water. Proper modelling of ice properties and forces is crucial in such cases to ensure safe operations, for example, Dynamic Positioning (DP). This work, therefore, aims at developing algorithms for image processing to extract useful ice properties and subsequently aid the modelling of ice load exerted on a floating platform or a ship. A robust algorithm capable of detecting closely connected and overlapped ice floes with various sizes and shapes is presented, which is the first step for accurate modelling of ice forces. To demonstrate the effectiveness of this approach, image frames processed from videos produced during an experiment using a model ship performed at the National Research Council’s Ocean Coastal and River Engineering Research Centre (NRC-OCRE) in Canada are used. Simulated ice floe images are also used to show the efficiency of the proposed model and compare it with other published work. The model will be extended further to extract and correlate other ice properties with the ice forces and develop a machine learning based ice force prediction model. The predicted force from that model will then be used as a feedforward to Dynamic Positioning (DP) controller with an aim to improve the performance of the controller.
Simulation Tool for Evaluation of Investment in Sustainable Technology
Authors: Gullaksen Joannes 
Published: October 2022

Abstract
Sustainable technology enables valuable use of natural resources and reduced ecological impact, whereas impact management is the ongoing practice of measuring, assessing and improving impacts on sustainability issues. The aims are to achieve the balance between economic, environmental and social impacts through the effective management of resources whilst maximising organisational profitability. A financial evaluation helps an investor to take rational decision about an analyzed investment, whereas an economic analysis broadens this perspective to include effects of the investment imposed on other stakeholders and the environment. Changing technology landscapes, development risks and new opportunities are characterized by a need of innovative financing and investment models in order to adequately assess the uncertainty and risks. Traditional quantitative analysis calculates measures of risk and financial return for hypothetical investments based on some time series for the analysis, that also should account for market dynamics. The shortcomings with this approach could be a single constituent dominate a risk and return profile, where noise is a random variation, including any variation that is not predicted, except in terms of a statistical distribution function. Simulation, however, improves on this by looking at the impact of many variables changing at the same time. The simulation process consists of successively generating random numbers, used to select from the probability distribution of each uncertain input parameter. The process continues repeatedly to obtain a sufficient number of variable values for statistical analysis and a sufficient number of output parameters, where probability curves are used to determine the likelihood of the outcome and create a picture of risk.
A Weibull Distribution-Based Parametrization for Encounter Wave Spectra
Authors: Zago Lariuss , Kawano Alexandre , Simos Alexandre Nicolaos , Gonçalves Rodolfo Trentin 
Published: October 2022

Abstract
The continuous monitoring of sea states is important for many activities, from gathering oceanographic data to the planning of ship operations. There are several means to infer sea conditions, with variable levels of accuracy. Among these, the methods based on on-board measurements of vessel motions have been addressed by many researchers, attracted mainly by its practicality regarding installation and maintenance issues. However, the idea of using vessels as wave sensor also brings restrictions, mainly associated with the filtering of short waves that causes no significant motions of the hull, and, furthermore, the vessel speed introduces considerable complexity in the mathematical inference procedure. A significant part of this complexity is associated with the triple-value problem related to stern wave conditions. In the context of a research that addresses an alternative method for the parametric estimation of sea waves based on vessels with forward speed, this article deals with the problem of devising a proper parametric representation of the wave energy distribution as seen in the ship’s reference frame, i.e., the encounter wave spectrum. A Weibull-distribution parametrization is proposed, for its ability to handle the significant variations of encounter wave spectrum shapes. Analyses performed for several combinations of wave directions, peak frequencies and vessel’s speed show that this approach is indeed capable of providing proper representation of the spectral shapes based on few parameters, both for bow and stern waves.
Drilling Performance Evaluation Through Bit Cutters Reconfigurations and Micro Fractures Initiation
Authors: Abugharara Abdelsalam , Tytler Oluwafemi , Butt Stephen 
Published: October 2022

Abstract
Drilling operations of petroleum wells are primarily applied to create channels through subsurface formations for oil and gas production. For best drilling performance, drilling parameters including weight on bit (WOB), rotary speed in Revolutions per Minute (rpm), drilling Fluid Rates (FR), etc. need to be applied optimally to enhance drilling performance, to reduce cost, and to minimize wear of downhole tools. In this research, the drilling performance was evaluated based on examining the Drilling Rate of Penetration (ROP) in granite blocks through changing the face of a multi diameter Polycrystalline Diamond Compact (PDC) bit into three different design scenarios including the Flat Base bit (FB), Drilling Hole Opener bit (DHO), and Coring Hole Opener bit (CHO). All input drilling parameters were kept constant and the only variable was the bit configuration.
The purpose of this research was to evaluate the change in the ROP and to establish an investigation on why ROP varies when bit is reconfigured just by repositioning cutters. By linking the ROP variation to the bit configuration, a possible phenomenon of creating micro fracturing could be the reason for the ROP enhancement. Taking the FB as a baseline, results showed an increase in ROP using DHO and CHO over FB bit. The idea behind this could lay behind initiating micro fractures resulting a weaker rock portion by the 1st drill path to be drilled by the upper part of the bit.
Based on the averaged results, ROP of DHO increased by 37.5 % at 5 kN and by 47.1 % at 10 kN. Similarly, the ROP of CHO increased by 12.5% at 5 kN and by 11.8 % at 10kN indicating that initiation of micro fractures could play a role in the enhancement of the ROP.