bluuebunny/crossref_metadata_2025_split huggingface dataset:
Classification of Ice-Induced Vibration Regimes of Offshore Wind Turbines
Authors: Hammer Tim C. , Owen Cody C. , van den Berg Marnix , Hendrikse Hayo 
Published: October 2022

Abstract
Ice-induced vibrations of offshore wind turbines on monopile foundations were investigated experimentally at the Aalto Ice Tank. A real-time hybrid test setup was developed allowing to accurately simulate the motion of a wind turbine in interaction with ice, incorporating the multi-modal aspects of the interaction and the effect of simultaneous ice and wind loading. Different vibration patterns were observed where some could be described based on the common terminology of intermittent crushing or continuous brittle crushing. However, not all resulting vibrations could be described accordingly. A combination of several global bending modes interacting with the ice resulted in high global ice loads and structural response. Such response is likely typical for an offshore wind turbine, owing to the dynamic characteristics of the structure. The type of interaction observed during the tests would be most critical for design as the largest bending moments in critical cross-sections of the foundations occur for this regime. A classification of ice-induced vibrations is proposed which encompasses the experimental observations for offshore wind turbines on the basis of the periodicity in the structural response at the ice action point.
The Effect of Fluid Contamination on Rheological Properties of Geopolymer Materials
Authors: Khalili Pouya , Khalifeh Mahmoud , Saasen Arild 
Published: October 2022

Abstract
Providing zonal isolation and ensuring long-term integrity are among the highest priorities in primary cementing during well construction. There are several factors that compromise a successful cementing job. One of them is contamination with drilling fluid. Since there is drilling fluid in the wellbore prior to pumping the cementitious material, it is highly likely that intermixing between these fluids occurs in the downhole, which in turn can lead to several effects on mechanical properties and rheological behavior of the Portland cement or alternative materials such as geopolymer. In the placement process of the cement slurry, spacer fluids and prewashes are pumped ahead of the cementitious slurry to minimize the intrusion of drilling fluid into the slurry and consequently improving bonding to the casing and formation. In designing spacer fluids that can efficiently displace the drilling fluid, it is necessary stress test the cementitious material. The rheological properties and density of both cementitious slurries and drilling fluids and must be evaluated. Failing to properly characterize the fluids in the wellbore may lead to developing a spacer or displacing fluid that can cause viscous fingering and leave a static mud layer in the annulus.
In the present work, rotational test with controlled shear rate and oscillatory test were conducted on drilling fluid (water-based and oil-based) and geopolymer to identify rheological behaviors. Based on the mentioned tests, storage and loss modulus, yield stress, and flow curve of the slurries were also measured. For completeness of measurements and comparison purposes, the flow curve was measured with both an API viscometer and a proper rheometer. Obtained parameters can give us a good understanding of the flow behavior of the fluids when pumped downhole under certain shear conditions and, as a result, establish a good basis for spacer design for geopolymer as a new under-development cementitious material.
Development of a Response Assessment Tool for a Floating Dock System
Authors: Zhang Jianan , Li Lin , Ong Muk Chen , El Beshbichi Omar , Kniat Aleksander 
Published: October 2022

Abstract
Docking operations of ships require a response assessment to ensure structural and personnel safety. Environmental loads and improper ballast adjustments are the main threats to the docking operations. They can cause severe structural damages and stability loss to a floating dock system which includes a floating dock and a docked vessel, even if the velocities of the dock and the vessel are very low during the docking process. Response assessment of the floating dock system, including structural strength analysis and stability check, needs to be performed for a safe docking operation. This paper aims to propose a framework of a floating dock system’s response assessment. The stages of ship docking operations are firstly described. The environmental and operational risks involved in those stages are discussed in detail. Then, relevant studies on the structural strength assessment and stability analysis of floating docks are reviewed. Based on the review, a framework to perform a response assessment of a floating dock system is proposed and discussed with a focus on the dynamic response analysis. A numerical model of the dynamic response assessment is established using the language Modelica. A preliminary case study of a single dock under pure wave conditions is presented.
A Coupled Wave-Current-Structure Study for a Floating Offshore Wind Turbine Platform
Authors: Li Xiang , Xiao Qing , Gonçalves Rodolfo T. , Peyrard Christophe 
Published: October 2022

Abstract
In the present study, the influence of ocean conditions, in the combination of wave and current, on the dynamic response of the OC4 semi-submersible platform is numerically studied. The present work is inspired by the recent observations that the presence of current incidence usually induces the vortex-induced motions (VIM) phenomenon of multi-monocolumn platforms, while wave often leads to large inertia force on it. The integration of wave and current may further cause a more complex flow field around the structure than that only wave or current exists. Such VIM is not desirable considering its impact on the fatigue life of the riser, umbilical, and mooring system of the offshore structure due to the resonance behaviour of the VIM.
A computational fluid dynamic (CFD) method is adopted to conduct a real-time simulation of the platform’s motion response. The tool is based on an open-source code library OpenFOAM. The results are validated against experiments with current-only conducted in the wave tank. The flow field around the platform and its impact on the structure motion and loading response are studied for a wide range of wave and current conditions. With the given incident waves, the VIM is mitigated for most cases, for a wide range of reduced velocity. This result is of practical interest for the design of FOWT, as VIM are not captured by industrial aero-hydro-mechanical models.
A Novel Approach in Modelling Fluid Flow in Unconventional Reservoirs Incorporating Viscous, Inertial, Diffusion, Desorption and Advection Forces Contributions
Authors: Aldhuhoori Mohammed , Belhaj Hadi , Ghosh Bisweswar , Alkuwaiti Hamda 
Published: October 2022

Abstract
A model for single-phase fluid flow in tight UCRs was previously produced by modifying the flow Forchheimer’s equation. The new modification addresses the fluid transport phenomena into three scales incorporating a diffusion term, a desorption term and an advection term. In this study, a new model has been numerically validated and verified using synthetic data. Ideally, the new model suits fluid flow in tight UCRs. The modified Forchheimer’s model presented, produced very simple profiles and flow dynamics of the main flow parameters have been established and a thorough parametric analysis and verifications were performed. It has been observed that a system containing the aforementioned forces becomes more prominent in regulating flow velocity with low permeability of the formation rock and low viscosity of the flowing fluid. The findings indicate a behavioral alignment with a previous hypothesis that matches actual reservoir behavior.
Jet Cleaning Processes in the Plug and Abandonment of Oil and Gas Wells: An Experimental Study on Horizontal Miscible Jets
Authors: Hassanzadeh Hossein , Cournoyer Elliott , Taghavi Seyed Mohammad 
Published: October 2022

Abstract
The plug and abandonment (P&A) operation is considered as one of the essential stages during life cycle of oil and gas wells. During the P&A operation, each well needs to go through the specific steps; these may include accessing behind the casing (i.e. annulus), cleaning the target area (i.e. inside and outside the casing), and installing the cement plug barriers in the target area. The jetting process is one of the efficient approaches in the cleaning step of P&A operation, where an injection fluid pushes and removes unwanted fluids/materials. To achieve an efficient jet cleaning process, studies on the effects of different parameters (e.g. operational parameters, fluid properties, and geometrical parameters) seem crucial.
In this paper, we experimentally study the characteristics of horizontal miscible jets, to develop an understanding about fundamental aspects of the jet cleaning process in P&A operation. We analyze the effects of the injection velocity, the perforation diameter, and the rheological parameters on jet characteristics, such as the laminar length and the mixing index. Based on our results, increasing the injection velocity leads to a decrease in the laminar length. Also, the mixing index before the perforated wall increases by decreasing the perforation diameter. In addition, using a non-Newtonian ambient fluid results in decreasing the mixing index.
Finding Dangerous Waves – Towards an Efficient Method to Obtain Wave Impact Design Loads for Marine Structures
Authors: van Essen Sanne , Seyffert Harleigh 
Published: October 2022

Abstract
Green water and slamming wave impacts can lead to severe damage or operability issues for marine structures. It is therefore essential to consider their probability and loads in design. This is difficult, as impacts are both hydrodynamically complex and relatively rare. The complexity requires high-fidelity modelling (experiments or CFD), whereas a statistically sound analysis of rare events requires long durations. High-fidelity tools are too demanding to run a Monte-Carlo simulation; low-fidelity tools do not include sufficient physical details. The use of extreme value theory and / or multi-fidelity modelling is therefore required. The present paper reviews the state-of-the-art methods to find wave impact design loads, which include response-conditioning methods, screening methods and adaptive sampling methods. Their benefits and shortcomings are discussed, as well as challenges for the wave impact problem. One challenge is the role of wave non-linearity. Another is the validation of the different methods; it is hard to obtain long-duration high-fidelity wave impact data. A planned case study is introduced, where different techniques will be put to the test and these challenges will be addressed.
A Validated Computation Fluid Dynamics Model Investigating Cuttings Transport With Herschel Bulkley Drilling Fluids
Authors: Khaled Mohamed Shafik , Khan Muhammad Saad , Rahman Mohammad Azizur , Hasan A. Rashid 
Published: October 2022

Abstract
A fundamental understanding of the impact of different hydrodynamic, scaling, and geometric conditions on cuttings transport are essential for successful wellbore drilling. This study presents a validated computational fluid dynamics (CFD) model for investigating cuttings transport phenomena in deviated wells with Herschel Bulkley drilling fluids at different drilling conditions.
A CFD model was developed and validated with our experiments conducted in the TAMUQ flow loop (5-meter horizontal length, 4.5in. × 2in.) and open literature. The Eulerian-Eulerian approach simulated solid-liquid laminar and turbulent flow in annular geometry utilizing hexahedral mesh under transient conditions.
It was observed that the optimum range for efficient hole cleaning is from 0–200 RPM, and increasing RPM above 200 will have a marginal impact on improving hole cleaning. Cuttings size of 0.004 m was determined to be the critical size for solid particle removal. Hole enlargement has a hugely adverse effect on the fluid-carrying capacity due to the reduction of fluid velocity in the enlarged section and cuttings concentrate. Poor hole cleaning signs were observed with increasing cuttings density and wellbore inclination between 45–60 degrees.
Mooring Line Failure Detection in the Absence of Load Monitoring
Authors: Naciri M. , Viola M. , Wang Z. , Yam R. 
Published: October 2022

Abstract
Mooring Integrity Management (MIM) is a key operational aspect for FPSO operators, mooring system designers and Recognized Classification Societies (RCS). MIM programs should include the capability to detect a mooring line failure. When direct or indirect measurement of line tension is available continuously and reliably over time, this requirement can be readily fulfilled. Current industry-wide experience shows it has been challenging to develop robust cost-effective real-time anchor line load monitoring systems for the offshore environment. To remedy this situation, Artificial Intelligence (AI) techniques are used to extract an intact or damage diagnosis for a spread moored unit offshore Brazil based on data readily available in situ. The Intelligent Agent (IA) developed has been reviewed by the Classification Society against Ref. [1] and [2]. Following this review a statement of maturity has been issued Ref. [3] qualifying the new technology.
Pore-Scale Investigation on Dynamic Permeability Characterization of Hydrate-Bearing Sediments
Authors: Chen Mingqiang , Li Qingping , Lyu Xin , Fan Qi , Ge Yang , Lyu Chaohui 
Published: October 2022

Abstract
Natural gas hydrates widely distributed in marine sediments and permafrost have attracted global attention as great potential energy resources. As an important parameter that critically affects the efficiency of gas hydrate production, reported permeability values are observed to be widely scattered due to multiple factors such as hydrate saturation, hydrate pore habit and so on, bringing a great challenge for accurate prediction. In this study, an unstructured hydrate-bearing network model with anisotropy is firstly constructed. Afterwards, a pore-scale flow network model considering hydrate pore shrinking habits is developed. Dynamic permeability evolution is then investigated under different hydrate saturations, pore connectivity, and pore throat size distribution conditions. Results show that the existence of hydrate changes the structure of the hydrate-bearing pore network, which reduces the pore and throat radius distribution as well as the distribution law. Since hydrate preferentially nucleates in large elements of the pore network, the deviation degree of the pore body radius is more significant than that of the throat radius. Dynamic permeability evolution with increased hydrate saturation shows a nonlinear decline trend due to the nonlinearity between pore structures and hydrate saturation variations. Owing to the two competing factors of pore structure variation and coordination number effects on pore-scale flow, dimensionless dynamic permeability under different pore connectivity shows a minor discrepancy. Pore throat size distribution possesses a significant impact on dynamic permeability evolution. Under the premise of fixed size distribution, number, and connectivity of the pore bodies, the smaller the initial throat radius, the more influence hydrate formation and dissociation on the network structure variation, resulting in smaller dimensionless permeability.
Real-Time Ship Motion Prediction Using Artificial Neural Network
Authors: Taskar Bhushan , Chua Kie Hian , Akamatsu Tatsuya , Kakuta Ryo , Yeow Song Wen , Niki Ryosuke , Nishizawa Keita , Magee Allan 
Published: October 2022

Abstract
Models based on Artificial Neural Networks (ANN) have been developed for predicting ship motions using the information about the wave field around the ship and historical time-series of motions. The ANN models developed in this study were able to predict all six degrees of freedom ship motions in irregular wave conditions with different significant waveheight, peak period and wave directions along with directional spreading. Preparation of training, validation and test datasets has been described along with the development and training of ANNs. The models were tested using the observed wave conditions recorded by a wave radar installed onboard the ship.
A physics-based approach has been applied when selecting the length of input and output data. The effect of input and output window length on the accuracy of results was further studied by developing two sets of ANNs with different length of input and output window. Performance of both sets of ANNs on training, validation and test datasets has been presented along with detailed investigation on test dataset. Reducing the length of input window and increasing the length of output window was seen to reduce the accuracy of prediction.
Hydrodynamic Motion Behavior of Air-Cushion-Supported Hexagonal Floating Platform for Offshore Wind Turbine
Authors: He Yining , Hirabayashi Shinichiro , Tabeta Shigeru , Nakajima Toshio , Yamashita Yoshihiko , Yamashita Yuuki , Imai Motoko 
Published: October 2022

Abstract
This paper presents an experimental study of a new floating platform, being supported by air-cushion modules. The platform consists of six hexahedron air cushion units in which their bottom is open to the water surface. A moonpool is placed in the middle of the platform. A 1:47 scale model was used for the measurement of heave, pitch and surge motions in regular wave conditions. To evaluate the effect of a hexahedron air cushion unit, that of barge-type model was tested. The results show that the motion behaviors of the hexagonal air-cushion-type platform are better than those of the barge-type platform in short wave conditions, while behaviors in long wavelength are almost the same.
To evaluate the stability of the hexagonal air-cushion-type platform in windy conditions, a wind turbine of a circular disc-shape was installed on the platform. The thrust acting on the wind turbine and the wind velocity were measured simultaneously. Further, the inclination test of a three-blade wind turbine model was carried out. The results show that the tested hexagonal air-cushion-type platform is sufficiently stable for the practical use of wind turbines of a 20MW capacity. Similarly, platforms of larger size could be used for wind turbines larger than 20MW.
Quadrature Schemes for the Integration of the Free-Surface Green’s Function Within the Open-Source Boundary Element Method Library BEMUse
Authors: Saverin Joseph R. , Grüter Laura 
Published: October 2022

Abstract
The direct boundary element method has a computational expense which scales quadratically with the number of panel elements. This is a significant bottleneck in the application of the method to large systems. As a preliminary step towards the implementation of a solver with linear computational expense, a detailed study is carried out to investigate quadrature schemes for the integration of the free-surface Green’s function over hydrodynamic panels in the frequency domain. Important parameters are investigated including quadrature order, quadrature rule and panel refinement. Integration errors are quantified by comparison to analytical expressions and higher-order quadrature schemes. Important observations relevant to the removal of irregular frequencies are observed for practical implementation into a boundary element method solver. The order of the method is demonstrated and the influence of the quadrature order on this scaling is quantified. The schemes have been implemented within the open-source boundary element code BEMUse. The ability of the quadrature schemes to correctly calculate the surface hydrodynamic potential is validated by comparing to analytical results for a submerged, oscillating hemisphere. The schemes are verified for realistic offshore wind energy floating platforms geometries by comparison to validated software. It is seen that the quadrature methods allow for accurate calculation of added mass, damping coefficients and excitation forces.
Analytical Model for Non-Bonded Flexible Pipe Under High Temperature and Axisymmetric Load and its Application in Upheaval Buckling
Authors: Chen Kunpeng , Zhang Mengmeng , Zhao Bing , Luo Chunmiao , Fu Shixiao 
Published: October 2022

Abstract
In order to prevent pipe blockage and reduce transportation costs, submarine pipes usually use the method of heating and pressurizing the pipe when transporting liquids. The high temperature and high pressure will cause the axial deformation of the submarine pipe, but due to the existence of the boundary between the two ends of the pipe, the axial deformation cannot be released and a certain axial force is generated. When axial force accumulates to a certain extent, buckling failure may occur, that is, thermal buckling of submarine pipes. In the process of buckling prediction, the axial force is an important input parameter. In the current engineering application, the non-bonded flexible pipe is often regarded as a steel pipe for fast calculation of the axial force value. However, since the geometry of the non-bonded pipe is very complex, the radial mutual extrusion and interlayer interaction will affect the axial deformation of the pipe. Therefore, it is not appropriate to simply use the deformation of the steel pipe to obtain the equivalent of the deformation of the non-bonded pipe to obtain the value of the axial force. In this paper, an analytical model for calculating the structural response of non-bonded pipes under high temperature loads and axisymmetric loads is proposed, and the structural responses of non-bonded pipes under high temperature loads and internal and external pressures are analyzed. The axial force is compared with the results obtained by the calculation methods commonly used in the current engineering. Further, the impact of these differences on the soft soil seabed upheaval buckling forecast is analyzed.
Mitigation of Barite Sagging for Proper Well Control: Lab Investigation and Field Application
Authors: Wagle Vikrant , AlYami Abdullah 
Published: October 2022

Abstract
For high-density fluids, achieving the right fluid formula with the right fluid rheology is difficult since excessive heat, dehydration, and solid loading can deteriorate mud properties. Addition of weighting materials such as barite is needed to achieve the desired density to overbalance the well and avoid any possible flow from the formation. However, maintaining a high volume of solid content for barite particles in suspension might be challenging, especially for extended period. The separation of barite from the mud can lead to undesirable density fluctuation as drilling fluid is being circulated throughout the hole. This phenomenon may lead to potential well control incidents and stuck pipes.
The objective of this study is to design new high-density water-based drilling fluids with lower solid content and mitigate the issues arising due to drilling with high-density drilling fluids. The experimental work in this paper involved rheological properties, thermal stability, HT/HP filtration, and static sagging (vertical and deviated) of 120 pcf and 150 pcf high density water-based drilling fluids. The paper will highlight field cases of proper maintenance program on fluid properties to mitigate any potential well control incidents and will recommend fluids formulation properties when using high solid content water-based fluids.