bluuebunny/crossref_metadata_2025_split huggingface dataset:
Port Plans to Reduce Disaster Damages of High Tide and Tsunamis
Authors: Takahashi Koji , Sugiyama Asami , Nakamura Shuichi , Shibata Daisuke 
Published: October 2022

Abstract
Japan’s major ports must be reorganized as part of the changes in the country’s industrial structure. The Port Management Bodies of the major ports intend to formulate or revise the Port Plan due to these changes.
On the other hand, in Japan, the occurrence of large-scale tsunamis or high tide that exceeds H.H.W.L are expected in the future. When port facilities are damaged by these natural disasters and port functions are paralyzed, the logistics base of the bulk cargo (crude oil, iron ore, coal etc.) which is not suitable for transport by land is more likely to suffer damage because the logistics base is located near the port. The logistics base of the bulk cargo (cereals, automobiles, etc.) and the container cargo which are suitable for long-distance transport by land suffers less damage. The reason for such less damage is that the logistics base is generally located a long way from the port. Port logistics can be restored early with non-damaged ports.
In recent years, Japan also saw increasing damages caused by rising sea levels and growing scale of typhoons due to the influence of climate change.
Today, it is necessary to verify that tsunamis and high tide occur at the same time.
The authors points out the importance of the backup ports using the sacrifice model considering the characteristics of such port logistics, and then, the importance of formulating or revising the port plans to reduce disaster damage from overtopping volumes caused by rising sea levels using Takayama’s method and CADMAS-SURF.
Finally, the authors propose the importance of formulating or revising the port plans to reduce disaster damage to realize these points and to prepare for large-scale natural disasters.
Restoration Models for Quantifying Resilience of FPS Under Mooring Failure
Authors: Wu Jingyi , Yu Yang , Yu Jianxing , Xu Lixin , Wu Fanlei , Chang Xueying 
Published: October 2022

Abstract
During its service life, floating production system (FPS) is exposed to various risks, with mooring failure being one of the catastrophic events. Based on the recorded failure data, it is definitely not a single event. Resilience investigation would improve the performance of FPS under adverse events. In order to assess and quantify the resilience of a FPS under mooring failure, it is essential to use reliable capacity restoration metrics and models. So far, there are no restoration models available for FPS under mooring failure, which help quantify the pace of post-failure capacity and functionality gain to facilitate well-informed decision making for reliable prioritization and efficient allocation of resources in restoration work. This paper proposed a reliable restoration model based on the schedule of restoration tasks for mooring repair. The restoration tasks are carefully analyzed and the key influence factor, damage extent is categorized. Proposed restoration models are then illustrated and validated by traditional FPS under mooring failure.
A Numerical Macro Model to Simulate the Whole Life Response of Anchors for Floating Offshore Renewable Energy Systems
Authors: Kwa Katherine A. , Sivasithamparam Nallathamby , Deeks Andrew , White David J. 
Published: October 2022

Abstract
The offshore renewable energy (ORE) industry is developing new solutions to enable floating facilities that can operate further from shore where more ocean space is available and stronger wind resources can be harnessed. Future ORE facilities will involve arrays of devices that connect and will transmit loads to the seafloor via mooring and anchoring systems. Therefore, it is essential to have a reliable estimation of the capacity that the anchoring system can provide for the variety of loads that are transmitted via the mooring lines.
This paper provides a model for soft soils (i.e. soft clays, loose-medium silts and sand), where the capacity can evolve with time due to the sustained loads and variable components of the cyclic loads, which vary due to environmental conditions and the characteristics of the floating system. The model is referred to as a ‘macro-model’, meaning that the response of all soil elements around the anchor are defined by a representative value of strength and other properties at a single node. The model captures ‘hidden’ anchor capacity enhancements from (i) ‘whole-life’ changing soil strength, (ii) viscous effects on soil strength and (iii) added soil mass effects, which are usually absent in geotechnical foundation design.
It is shown that these effects can be efficiently modelled and integrated into existing numerical analysis packages to provide a new basis for assessing through-life changes in geotechnical anchor capacity. This enables a better understanding of the fully coupled soil-anchoring-mooring behaviour of floating infrastructure over its operational lifetime.
Expanded Vermiculite Blended Foamed Cement Composite for Geothermal Wells Cementing and Its High Temperature Adaptability
Authors: Zhou Wei , Wang Chengwen , Lu Haoxin 
Published: October 2022

Abstract
Geothermal resource is a clean and efficient unconventional energy source. It is crucial to reduce heat loss along shallow interval around non-net for efficient use of geothermal energy. One potential method is to create a cement sheath with good mechanical and insulation properties through well cementing. However, there are few relevant studies. In this paper, the foamed cement slurry with good thermal insulation performance was prepared by a new nitrogen gas generating reactant, and the properties of cement slurry were further optimized by nano oxide and expanded vermiculite. The results show that: the foam distribution in self-generating nitrogen foamed cement is uniform and stable, which is beneficial to ensure the mechanical strength and thermal insulation ability of cement stone; The thermal conductivity of the cement stone with 5–8% expanded vermiculite can be reduced to 0.3719 W/m·k after curing for 48 h at 120 °C, and there is no adverse effects on the compressive strength of cement stone; Nano oxide can improve the mechanical properties and temperature resistance of the cement stone; The compressive strength of foamed cement composite remains above 18 MPa after curing for 48 h at 120 °C, without obvious deterioration of the cement performance. This research can provide reliable technical means for efficient exploration of geothermal energy.
Observations on Horizontal Velocities Under Waves in Shallow Water at a Wave Energy Site
Authors: Vogler Arne , Miguez Diego , Pepper Ben 
Published: October 2022

Abstract
Based on a two-year dataset from a bottom mounted ADCP in shallow water the horizontal particle velocities under waves are analysed in this paper. The sensor was deployed at one of the most exposed coastlines of the UK at a prospective wave energy site and good data returns were obtained throughout the deployment period. The distributions of wave heights, periods, and particle velocities are analysed for all observed individual waves. Waves were binned into combinations of a range of wave heights and periods and the average values of the measured peak horizontal velocities per bin are compared against wave theory. Results show that the average of the measured values per bin compares reasonably well against theory, with measured values slightly exceeding the calculated results. Good similarity was observed between shorewards and seawards setting velocities under the waves, with higher values observed for shorewards facing velocities. Distributions of shorewards setting velocities in each bin were analysed with Kernel and Burr distributions providing good estimations of them. The maximum observed velocities for all bins were more than twice of either the average value per bin or the theoretically derived values. Results described here are relevant to stress or fatigue calculations of coastal structures, moorings and cables, aquaculture, wave surge energy converters, or sediment transport studies.
Nonlinear Moment-Based Optimal Control of Wave Energy Converters With Non-Ideal Power Take-Off Systems
Authors: Faedo Nicolás , Giorgi Giuseppe , Ringwood John V. , Mattiazzo Giuliana 
Published: October 2022

Abstract
The mechanical-to-electrical energy conversion stage in wave energy devices is commonly affected by losses associated with the power take-off (PTO) system, inevitably leading to non-ideal conversion in practical scenarios. Such behaviour needs to be incorporated within the wave energy converter (WEC) energy-maximising control design procedure, so as to guarantee optimal operation of the device under these non-ideal conditions. Motivated by this requirement, we present, in this paper, a nonlinear moment-based energy-maximising control solution for WECs under non-ideal PTO behaviour. We show that the mathematical formalism proposed always admits a globally optimal energy-maximising solution, facilitating the application of state-of-the-art numerical routines, leading to real-time performance. Numerical results are presented for a heaving point absorber WEC system, illustrating the capabilities of the proposed controller in a non-ideal PTO conversion scenario, including a comparison with a benchmark control strategy.
Smooth Carcass for Flexible Pipe –Field Case Study
Authors: Barbier Jérémie , Holyst Cyril , Phelut Renaud , Tran Eric 
Published: October 2022

Abstract
This paper presents the complete qualification of the TechnipFMC flexible pipe Anti-FLIP solution termed Smooth-Carcass and uses a case study to show how this technology is a versatile and cost-effective solution to improve hydraulic performances of tie-back developments. The first commercial project for Smooth Carcass technology consists of 2 subsea wells gas tie-back to an existing facility connected by a total of 24 kms of flexible flowlines. Hydraulic modelling has been used to demonstrate the benefit of Smooth Carcass flexible pipe compared to a conventional rough bore flowline, reducing pressure losses in the production system. Hydraulic performance results are presented for different internal flowline diameters and roughness values considering the bathymetry of the field (180m to 1000m water depth) and tie-back distance to existing facility (∼20km). It is found that Smooth Carcass technology reduces pressure loss when benchmarked to a conventional carcass flexible pipe with a positive cost impact on procurement and installation by reducing flowline diameter size requirements.
Beyond the primary anti FLIP properties (Flow Induced Pulsation); Smooth Carcass is an evolution of the conventional carcass reducing pressure losses and optimizing bore size as well as upper flexible pipe layers. This paper demonstrates that Smooth Carcass is a smart, versatile and cost-effective solution which can add significant value to the customer and be a key enabler for future field developments.
Rationale for NORSOK U-001 5th Edition Revision of Static and Cyclic Subsea Wellhead Loads
Authors: Holden Harald , Muff Anthony , Reinås Lorents 
Published: October 2022

Abstract
NORSOK U-001 is a Norwegian national standard with requirements and recommendations that are supplementary to the ISO 13628 series of standards. NORSOK U-001 4th edition was issued in 2015 and carried a significant revision of design drilling riser loads applicable to subsea structures and well equipment. These maximum wellhead design loads were based on an analytical study followed by verification efforts indicating a shallow water under estimation bias of ULS and ALS design loads and overestimation bias of FLS design loads. As for cyclic design wellhead loads the NORSOK U-001 4th edition included informative design load histograms classified by BOP weight and water depth classes. As a part of development of NORSOK U-001 5th edition, a new wellhead load study has been performed to establish normative maximum and cyclic design loads for subsea wells.
The objective of this paper is threefold; first to present the analysis methodology employed and explain how loads have been established. The analysis work included more than 60 000 dynamic global riser simulations of marine risers from 5 different semi-submersible drilling rigs at water depths from 80 to 1000 m. Secondly, to explain how design loads have been extracted from these results for the upcoming 5th edition. A water depth reclassification was carried out with the intent to better cater for the shallow water bias from the 4th edition. Normative cyclic loads are based on a normalized load histogram scalable by a cyclic design load value (ΔMo) determined by water depth and operational mode. Finally, to outline quantified advice on maximum and cyclic load reduction potential that can be extracted from the underlying studies.
Ship Path Following Control via Output Redefinition Method in Restricted Waters
Authors: Zhou Xueqian , Xin Ping , Jia Dezheng , Huang Jin , Xu Donghao 
Published: October 2022

Abstract
Due to the advances in shipbuilding technology and the needs in the shipping industry, the ship dimensions have kept increasing, and so is the traffic in the ports, approach channels, and harbors. Increase in ship dimensions and traffic in restricted waterways results in challenges in waterway transportation safety. Safe maneuver of ships of overtaking and encounter is one of them. This paper addresses the problem of the path control of ships in parallel motion in restricted waters accounting for the hydrodynamic effects, in which, the path control with nonminimum phase zero dynamics is a major concern. A new output redefinition method has been developed to solve the nonminimum phase zero dynamics. With the assumption of low-frequency ship motion in restricted waters and the use of the output redefinition method, a new ship response equation is proposed. Based on the new ship response equation, a feedforward + PID control law has been developed to control ship parallel motion in restricted waters. Simulation results show good control effect in medium hydrodynamic interaction, the control law and ship response equation can enhance the safety of ships moving in restricted waters.
Activation of Local Bentonite for Oil and Gas Industry Application
Authors: Al-Yami Abdullah , Al-Safran Ali 
Published: October 2022

Abstract
Magzoub, et al 20171 have proposed a method of converting calcium bentonite to sodium bentonite. The method will require a reactor for upscaling. The method involves preparation of soda ash solution, heating, mixing for at least 24 hours and finally removing impurities and drying out. Besun et al. 19972 have proposed a method that will require also a reactor facility to upscale. Starch has to be added in water then bentonite is added in a separate water solution. Both were mixed and heated to form a structure of bentonite-starch gel. The formed gel has 20% starch and 80% bentonite. Bentonite is used in different applications such as drilling fluid, leaching earth, and animal feed additive.3 Sodium bentonite is more attractive in applications such as drilling due to its high swelling and good fluid loss control which makes it always in high demand. 4 & 5 The objectives of this study are to investigate and characterize local calcium bentonite in Saudi Arabia and to find optimum method to activate it for application in drilling fluids and cementing.
The characterization performed utilized XRF, XRD, and ESEM backscattered electron images along with EDS spectra for samples collected from different depths (5 meter and 7-meter samples). API testing including viscosity and fluid loss measurements were also conducted in the characterization phase. Activation was done utilizing cost effective additives such as soda ash. The activated bentonite was testing using standard testing procedures for drilling fluids and cementing such as rheology, fluid loss control, settling, compressive strength and thickening time tests.
The characterization concluded that the samples consisted mainly of Na-montmorillonite with appreciable amounts of impurities of quartz, kaolinite, illite, albite, calcite, and hematite. Compared to API reference sample, the local bentonite samples had less Na-montmorillonite contents, which probably needs some treatments to improve their quality. From this characterization, we can tell that activation of the 7 meter will be easier than the 5-meter bentonite because the Sodium Montmorillonite content is higher. The activation effort was focused on the 7-meter local bentonite sample since it showed better properties in terms of viscosity build up and fluid loss control. A new cost-effective activation method was conducted compared to the previous methods in the literature. Soda ash is an important step to convert or to increase the Na/Ca ratio to ensure higher swelling capacity.
Establishing New Guidelines for Stability Testing of Cementing Mix Fluids
Authors: Al-Yami Abdullah , Wagle Vikrant 
Published: October 2022

Abstract
American Petroleum Institute (API) has led for more than 85 years the development of equipment and operating standards in petroleum and petrochemical industries. API maintains 685 standards and recommended practices which have been also followed by international organization for standardization (ISO). Currently, there are no established guidelines in the industry to evaluate stability of cementing-mix fluids with time prior to mixing and pumping with cement.
API specification is not the same as API recommended practice. Specifications apply to pure materials while recommended practices are used on daily basis for cement slurries. Recommended practices can be modified and altered to be more suitable to field cementing operations and this is the main topic of this paper, to establish guidelines addressing stability of mix fluid in terms of thickening time, fluid loss, and most importantly the stability of latex and polymers within the mix fluid to ensure proper resistance against temperature and pressure cycling. To the best of the authors’ knowledge this is the first study to establish such guidelines.
API objective is to have a group of tests that produce consistent, reproducible results from test to test and from one lab to another. API only consider small part of testing so we should not be disqualifying additional tests because they are not API.
In addition to standard tests such as thickening time, rheology, and fluid loss. New and quick tests were designed to evaluate polymer and latex stability within the mix fluid that can be performed in a quick and an effective way to support the operator decision of dumping or maintaining the mix fluids with time for the cementing operations. Such a critical decision can not only be achieved by the standard API testing such as thickening time, rheology, fluid loss, etc. The consequence can definitely affect wellbore isolation and well performance. If the stability is not tested properly, then the cementing pumping operations can be achieved however we might end up with improper zonal isolation when changing mud weight or conducing fracturing operations.
Machine Learning in Fatigue Analysis for an Unbonded Flexible Riser
Authors: Yuan Jiabei , Zhu Linfa , Hou Yucheng , Tan Zhimin 
Published: October 2022

Abstract
Flexible pipelines are widely used in the offshore oil and gas projects. Comparing to steel pipes, flexible risers consist of multiple components layers, with each layer serving designated functions. For example, the helical tensile layers are used to work against axial tension from static pipe weight and amplification from the dynamic motions. As the risers are constantly experiencing stress variations due to different loadings, the fatigue performance of the tensile layers is essential to the design and operation of the flexible pipe system. Global and local fatigue analyses are usually performed in the design stage to estimate the fatigue life of tensile layers. Various parameters like vessel characteristic, pressure and temperature, environmental loadings affect the riser long-term performance. Also, multiple locations like top end fitting, bend stiffener region, touch-down zone are all potential fatigue hot-spots. To evaluate the fatigue damage at these locations, the industry standard practice is to run fatigue analysis in time domain with irregular wave. This approach is however time and resource consuming, especially when the designers have to consider thousands of load cases with long duration for numerous combinations of sea-states and operating conditions.
Baker Hughes developed a frequency domain technique for fatigue assessment on tensile layers of flexible risers. The approach builds transfer functions based on chosen time domain simulation and predict the total stress spectrum for other cases. Dirlik’s approximation method is used to estimate the fatigue damage based on the stress spectrum. Comparing to time domain approach, this approach is considerably more efficient in implementation. Since frequency domain technique simplifies the riser response as a linear system, the discrepancy must be addressed by calibration factors. To improve accuracy, more transfer functions are required to be built prior to the damage calculation.
In this paper, Baker Hughes introduces artificial neural network (ANN) technique to the developed frequency domain fatigue damage methodology. The ANN model is built between the wave spectrum and stress spectrum. Unlike the general AI technique, the type of neuron at each layer is carefully selected to represent the dynamic behavior of the riser system to improve the model efficiency. The ANN model is trained based on selected sea states. The trained model is used to predict riser damage and compared to that calculated from the time domain approach.
Analyzing Flexural Strength Data of Ice: How Useful Is Explainable Machine Learning?
Authors: Buil Patrik , Kellner Leon , Ehlers Sören , von Bock und Polach Franz 
Published: October 2022

Abstract
The climate crisis results in a rapid sea ice decline, making shipping routes accessible for longer durations throughout the year and therefore increasing maritime traffic. At the same time, ice-structure interaction is known to cause damage to ships and structures. In this context, the flexural strength is a key property of the ice. It is also an important factor in the process of the formation of ice ridges which then act as obstacles to marine transit.
Due to the complexity of natural materials, whose properties are often determined by many influencing variables, the development of a suitable material model for ice remains a major challenge. Many experimental studies on flexural strength have been done whose results can be used to draw conclusions about the material properties. However, a major drawback is that these experiments differ significantly regarding, e.g., test method, ice conditions, measured variables and testing boundary conditions, which makes a comparison as well as the derivation of general laws for material properties of ice challenging. Moreover, most studies investigate univariate relationships whereas in reality the behavior of ice is influenced by numerous factors.
In this paper an explainable machine learning approach to analyze data from various bending tests and to identify relevant features regarding the flexural strength of ice is presented. Using an approach similar to Kellner et al. [1,2], a database of flexural strength tests is established. The data is used to create machine learning models, whose predictions are interpreted with the explainable AI (XAI) method Shapley Additive exPlanaionts (SHAP). The goal is to show a new approach to investigate the flexural strength of ice and to get a better understanding of how suitable the use of XAI for this problem is.