bluuebunny/crossref_metadata_2025 huggingface dataset:
Basophil activation test for allergic and febrile non‐haemolytic transfusion reactions among paediatric patients with haematological or oncological disease
Authors: Usami Yoko , Yanagisawa Ryu , Kanai Ryo , Ide Yuichiro , Konno Saori , Iwama Maria , Futatsugi Akiko , Takeshita Tomoko , Furui Yu , Komori Kazutoshi , Kurata Takashi , Saito Shoji , Tanaka Miyuki , Nakazawa Yozo , Sakashita Kazuo , Tozuka Minoru
Published: October 2022

Background and Objectives

Allergic transfusion reactions (ATRs) and febrile non‐haemolytic transfusion reactions (FNHTRs) are common, although their mechanisms remain unclear. Immunoglobulin E (IgE)‐mediated type I hypersensitivity may be involved in the pathogenesis of ATR. A basophil activation test (BAT) may help elucidate this process.

Materials and Methods

The BAT was based on peripheral blood samples from paediatric patients with a haematological or oncological disease and on samples of residual blood products transfused in each case. Dasatinib was used to evaluate whether basophil activation was mediated by an IgE‐dependent pathway.

Results

Twenty‐seven patients with and 19 patients without ATR/FNHTR were included in this study, respectively. The median BAT values associated with ATR‐ (n = 41) and FNHTR‐causing (n = 5) blood products were 22.1% (range = 6.1%–77.0%) and 27.8% (range = 15.2%–47.8%), respectively, which were higher than the median value of 8.5% (range = 1.1%–40.9%) observed in blood products without a transfusion reaction. Dasatinib suppressed basophil activity. BAT values were comparable in patients with ATR regardless of severity. Meanwhile, BAT values analysed with blood products non‐causal for ATR/FNHTR were higher in patients with ATR/FNHTR than in those without.

Conclusion

The IgE‐mediated type I hypersensitivity may be involved in the pathogenesis of ATR and FNHTR. BAT analyses may help elucidate the underlying mechanisms and identify patients at risk.
Re‐emergence of rabies in Mazowieckie Voivodeship, Poland, 2021
Authors: Smreczak Marcin , Orłowska Anna , Trębas Paweł , Stolarek Agnieszka , Freuling Conrad , Müller Thomas
Published: October 2022

Due to the oral vaccination of foxes against rabies most of the territory of Poland was freed from rabies of non‐flying mammals. In January 2021, rabies was diagnosed in fox in the central part of Mazowieckie Voivodeship where rabies has not been detected since last 17 years. Subsequently, in the following months the rabies virus infection spread southward reaching the voivodeship of Świętokrzyskie in November 2021. Emergency actions were implemented aiming at rapid rabies elimination.
Study of The Effect of Model Geometry and Body Mass Index on The Elastohydrodynamic Lubrication Performance of Metal-on-Metal Hip Joints
Authors: Basri Hasan Basri , Doni Tri Satya Ramadhoni , Prakoso Akbar Teguh Prakoso , Imam Muhammad Imam Ammarullah , Jamari J Jamari
Published: October 2022

This study aims to provide benefits on the manufacturing side in considering design parameters for optimization of total hip arthroplasty based on body mass index (BMI) categories. The femoral and cup geometries in Total Hip Arthoplasty (THA) are modeled in a simple ball-on-plane form to analyze the pressure and thickness of the lubricant film in the elastohydrodynamic lubrication of artificial hip joints with vertical loads and parameters based on body mass index using the finite element method. The factor of being overweight is one of the causes of increasing the maximum load during activities. This study applies a maximum load based on BMI which is divided into two categories, namely normal and high BMI to obtain the distribution of contact pressure and fluid pressure on the bearing surfaces that are in contact with each other so that the thickness of the lubricating film formed can be determined. Validation of contact pressure and film thickness was carried out. The femoral head sizes applied were 24mm and 28mm with a radial clearance of 15μm, 30μm and 100μm using CoCrMo metal material. From the simulation the load at high BMI shows an increase by a large enough difference reaching 16.89MPa at contact pressure, 19.88MPa at fluid pressure and 0.004μm at the thickness of the lubricant film compared to normal BMI. This simple modeling provides the benefit of analyzing the effect of body mass index on tribological THA performance and can help reduce the growth rate of THA implantation failure revision surgery.
3D Bioprinting: Introduction and Recent Advancement
Authors: Khalida Fakhruddin  , Belal Yahya Hussein Al-Tam  , Abdallah Nasser Sayed  , Zarin Mesbah  , Angelique Maryann Pereira Anthony Jerald Pereira  , Al Ameerah Elza Toto Syaputri  , Mohamad Ikhwan Jamaludin
Published: October 2022

In the additive manufacturing method known as 3D bioprinting, living cells and nutrients are joined with organic and biological components to produce synthetic structures that resemble natural human tissues. To put it another way, bioprinting is a type of 3D printing that can create anything from bone tissue and blood vessels to living tissues for a range of medical purposes, including tissue engineering and drug testing and discovery. During the bioprinting process, a solution of a biomaterial or a mixture of several biomaterials in the hydrogel form, usually encapsulating the desired cell types, which are termed as bioink, is used for creating tissue constructs. This bioink can be cross-linked or stabilised during or immediately after bioprinting to generate the designed construct's final shape, structure, and architecture. This report thus offers a comprehensive review of the 3D bioprinting technology along with associated 3D bioprinting methods including ink-jet printing, extrusion printing, stereolithography, laser-assisted bioprinting and microfluidic techniques. We also focus on the types of materials, cell source, maturing, the implant of various representative tissue and organs, including blood vessels, bone and cartilage as well as recent advancements related to 3D bioprinting technology.
Auto Segmentation of Lymph Node Microscopy Images
Authors: Sahalan Mariaulpa , Aidil Munir Mazlee  , Farah Nabila Mustafa Amirrudin  , Nurafiqah Syazwani Mohd Jamil  , Rahwani Nasir  , Nusrah Athirah Suhaimi  , Jareer Murtaza Amin  , Ahmad Naqib Mohd Qari
Published: October 2022

The manual histology assessment on the biopsy tissue sample still remains the gold standard procedure for cancer  and its progression in human body. Auto nuclei segmentation is an important method to measure cellularity but often suffered an issue due to the  present of overlapping nuclei. The implementation of auto segmentation of cells could speed up the process of histology assessment for cancer cases. The first step to implement, a wide data profile of normal and cancerous need to be compile and analyze further as a reference guide. Tissue data profile can be collected based on cellularity property of the tissue which can be automatically segmented using MATLAB software. The objective of the study is to develop an auto nuclei segmentation using MATLAB software to measure cellularity between normal and cancerous cells of lymph node tissue. Histological images of the tissue were analyzed using MATLAB software by using thresholding method and the result was compared with ImageJ. The pre-processing part of the image processing incudes converting the image into 8-bit grayscale image. The segmentation parts include adaptive filtering to remove the noise using Wiener filter and the thresholding Otsu method. Results from the ImajeJ and manual counting on the cellularity shows a comparable results to the automated cellularity measured using MATLAB. The cellularity of the cancerous lymph nodes was found lower than normal lymph nodes.
Evaluation on the Antibacterial Activity and Biocompatibility Natural Soap Formulated with Edible Bird Nest
Authors: Jumat Mohamad Amin , Hamzah Mohd Syahir Anwar , Mohd Daud Nurrizati , Saidin Syafiqah
Published: October 2022

Edible bird’s nest (EBN) derived from saliva of swiftlet is often consumed for its nutritional benefit. In this study, EBN natural soap was studied based on their morphology, antibacterial activity and cytotoxicity. The surface morphology and the presence of heavy metal in the soaps were investigated through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The antibacterial activity of EBN natural soap against Escherichia coli ATCC 25922 was investigated using disc diffusion and bacterial colony count method while the biocompatibility property was determined with human skin fibroblast cells through MTT assay and morphology observation under an inverted microscope. A consistent surface morphology pattern and no heavy metal were recorded on the soaps. The results of antibacterial activity indicated that the EBN natural soap did not have any antibacterial property but able to retain high cell viability percentage of 91.88±3.04% with normal cell morphology. Therefore, the EBN natural soap is biocompatible and appropriate to be incorporated in skin products.
The Influence of Hand Tracking and Haptic Feedback for Virtual Prototype Evaluation in the Product Design Process
Authors: Palacios-Ibáñez Almudena , Alonso-García María , Contero Manuel , Camba Jorge D.
Published: October 2022

Product evaluation throughout the design process is a fundamental task for product success, which also helps to reduce design-related costs. Physical prototyping is a common method to assess design alternatives, but often requires significant amounts of time and money. Extended reality (XR) technologies are changing how products are presented to the user, making virtual prototyping an effective tool for product evaluation. However, it is generally assumed that our perceptual and emotional responses to a product viewed in an XR modality are comparable to those elicited by the physical product. This paper reports the results of a study where a group of participants evaluated three designs of a product (i.e., umbrella stands) when viewed in a real setting, virtual reality (VR), and VR with passive haptics. Our goal was to observe the influence of visual media in product perception, and how the use of a complementary item (i.e., a physical umbrella) for interaction as well as user design expertise influence product assessment. Results show that the Jordan’s psycho-pleasure category of assessment was the most affected by the presentation medium, whereas the ideo-pleasure category was the only category not influenced by the medium. We also highlight that the use of VR with passive haptics could be an effective tool for product evaluation, as illustrated by the study of umbrella stands and young consumers. Our study also shows that the user’s background does not influence the level of confidence in their responses, but it can influence the assessment of certain product features. Finally, the use of a complementary item for interaction may have a significant effect on product perception.
Deterioration and Instability of Heat Transfer to H2O/CO2 Mixtures in Near-Critical Region for Horizontal Flow
Authors: Zhang Hanlin , Liu Dong , Li Qiang
Published: October 2022

In this work, we experimentally investigated the deterioration and instability of heat transfer to H2O/CO2 mixtures in the near-critical region, following our series of works on their normal and enhanced heat transfer, hydraulic resistance, and thermophysical properties. The experimental pressure is 24 MPa, temperatures are 330–400 °C, CO2 mass fractions are 9.8 and 15.0%, mass fluxes are above 940 kg/m2/s, heat fluxes are below 211 kW/m2, and flow is horizontal. Experiments show that the heat transfer deterioration for the supercritical H2O/CO2 mixture occurs when the fluid temperature is lower than the pseudo-critical temperature (Tpc) and the wall temperature is higher than Tpc, similar to the condition for supercritical pure fluids, but the onset heat flux is much lower. Results also show that the heat transfer instability for the supercritical H2O/CO2 mixture occurs not only moderately near Tpc (similar to supercritical pure fluids) but also more significantly near the critical miscible temperature. All of these distinct phenomena were attributed to the mixture feature.
Forced Response Induced by Low Engine Order Under Circumferential Inlet Distortions With Different Extents
Authors: Pan Tianyu , Yan Zhaoqi , Lu Hanan , Li Qiushi , Kielb Robert E.
Published: October 2022

Boundary-layer ingestion systems have the potential to improve propulsion efficiency using fluid with lower momentum near the airframe. However, they also bring variations in the velocity and total pressure, leading to a complex distortion of the flow at the inlet stage in the form of a circumferential step variation with significant strength. Previous simulation of NASA Rotor 67 under a 120-deg sector distortion revealed the occurrence of first-order bending mode excited by the second engine order (2EO) under circumferentially distorted inflow. To explore if the variation of distortion extent could affect the excited mode, five cases are simulated for different sector angles of distortion extent: 60, 90, 120, 150, and 180 deg. The result of modal-force analysis demonstrates that the modal force increases from the 60-deg case to the 90-deg case and then decreases from the 90-deg case to the 180-deg case, and the lowest value is reached in the 180-deg case. To further investigate the excitation sources leading to such variations of modal force, the harmonic force caused by periodic flow is analyzed based on the Fourier decomposition. The results indicate two main sources for the excitation of 2EO: (1) the harmonic force induced by the distorted inflow, and (2) the dynamic response of the fan blade caused by a sudden drop of inlet total pressure and controlled by the time constant.
Impacts of the Additive Manufacturing Process on the Roughness of Engine Scale Vanes and Cooling Channels
Authors: Wildgoose Alexander J. , A. Thole Karen , Subramanian Ramesh , Kersting Lisa , Kulkarni Anand
Published: October 2022

By leveraging the additive manufacturing (AM) platform, development time and costs for turbine component testing can be reduced relative to traditional investment casting. Surface roughness is a key characteristic of the additive manufacturing process that can impact flow, heat transfer, and mechanical integrity of printed components. There are multiple design and build considerations that result in variability in surface roughness, especially when additively fabricating complicated three-dimensional vanes and internal cooling passages. This study characterizes the surface roughness of internal cooling passages, vanes, and flat external surface samples made using additive manufacturing, specifically the direct metal laser sintering process. The samples were manufactured with various wall thicknesses, layer thicknesses, build locations, build directions, and on different AM machines. A combination of computed tomography scanning and optical profilometry was used to evaluate surface roughness levels. The data indicate that the dominant factors in roughness for a given layer thickness are a function of wall thickness, build location, and build direction.
Investigating the Increase in Energy Storage Density of Subsea Hydro-Pneumatic Accumulators Using a Compressible Fluid Undergoing Phase Change
Authors: Cutajar Charise , Sant Tonio , Briffa Luke J. , Buhagiar Daniel
Published: October 2022

The integration of energy storage systems (ESS) on a large-scale is becoming essential to mitigate intermittency issues in power supply from offshore wind farms. This paper deals with an offshore Hydro-Pneumatic Energy Storage (HPES) system comprising of a subsea accumulator pre-charged with a compressed gas. The paper applies a simplified thermodynamic model to investigate the potential increase in the energy storage density of the proposed HPES system by replacing air with carbon dioxide (CO2) that is able to undergo a phase change (gas-liquid-gas) during the storage cycle when limiting the peak operating pressure below the critical point. The study is based on a numerical model for simulating the thermodynamics of the entire storage cycle. A sensitivity study is conducted to examine the influence of main operational parameters, primarily the seawater temperature, peak working pressure and sea depth, on the storage density of the HPES system operating with a dual phase fluid. It is shown that the storage density of HPES accumulators can be increased substantially by using CO2 in lieu of air. The increase in density is found to depend considerably on the seawater temperature and sea depth.
Transient Cuttings Transport for Real-Time Systems
Authors: Aragall Roger , Starostin Alexander , May Roland , Dahl Thomas
Published: October 2022

Control of cuttings in well drilling results in higher operation performance and mitigation of critical pipe stuck events. Nowadays, digital twins for rig operations drive drilling automation services, where hole cleaning is a continuous and essential process. For efficient automation, models should enable real-time evaluation of cuttings transport.

This work presents a pragmatic transient one-dimensional model of cuttings transport in the annular section. The model is based on a coupling of the drift-flux model with a two-layer approach. The one-dimensional implementation presented here solves the momentum and mass conservation equations of drilling fluid with cuttings, and mass conservation equation for suspended cuttings. The latter is coupled with the mass conservation equation of stationary cuttings through erosion and deposition fluxes. The direction of the fluxes is determined according to the maximal cuttings bed heights evaluated with mechanistic models. Moreover, the rates of the fluxes are functions of operating parameters. We make use of diverse closure relations available in the literature for cuttings bed heights, slip velocities and pressure losses and combine them with new closures derived from CFD simulations of wellbore segments. The CFD-based closure relations consider drill string eccentricity and rotation.

The model can supply equivalent circulating densities (ECD), equivalent static densities (ESD) and cuttings volume returns. We validate the model with field data from the North Sea, where all the necessary data to set up the case was available: (1) wellbore survey points, (2) wellbore and drill string geometry, (3) drilling mud rheological properties, (4) cuttings properties, (5) mud composition, (6) temperature points and (7) operating parameters recorded with a frequency of 1 Hz. We compare simulation and measurement of ECD values and cuttings returns. The combination of the transient cuttings transport model with appropriate preprocessing of the input drilling fluid density and rate of penetration results in ECD predictions with errors below 0.02 specific gravity.
Preliminary Study of Floating Offshore Wind Turbines Motions Using the Smoothed Particle Hydrodynamics Method
Authors: Tagliafierro Bonaventura , Karimirad Madjid , Martínez-Estévez Iván , Domínguez José M. , Crespo Alejandro J. C. , Gómez-Gesteira Moncho , Viccione Giacomo
Published: October 2022

The open-source code DualSPHysics, based on the Smoothed Particle Hydrodynamics (SPH) method for solving fluid mechanics problems, defines a complete numerical environment for simulating the interaction of floating structures with waves and currents, and includes external libraries to simulate kinematic- and dynamic-type restrictions. In this work, we propose a full validation of the presented SPH framework using validation data available for an experimental test campaign on a 1:37th-scale FOWT TLP. The first set of validation cases includes a surge decay test, to assess the quality of the fluid-solid interaction, and regular wave tests, which stimulate the mooring system to a large extent. During this phase, tendons (tension legs) that are simulated by MoorDyn+ are validated. Secondly, the numerical model has proven to predict with a high degree of accuracy the response of the investigated TLP under regular waves. Spectral comparison shows that the model is able to capture the surge and pitch dynamic amplification that occurs around the resonant fundamental mode of vibration.
Wave-Induced Loads Acting on Monopile Configurations Considering Wake Effects
Authors: Thome Michael , el Moctar Ould , Schellin Thomas
Published: October 2022

This comparative study investigated wave-induced impact loads acting on two aligned cylinders placed in a wave canal. Initially, loads acting on a single cylinder in a focused wave were experimentally measured to validate the associated numerical predictions. Subsequently, four scenarios were considered, of which the first scenario dealt with the direct calculation of loads on a single cylinder, albeit with cylinders of three different diameters. The second scenario considered two cylinders of the same diameter, which were implemented in tandem. The loads acting on the upstream and downstream cylinders were calculated directly considering the wake effects on the downstream cylinder. For the third scenario, both cylinders were removed, and the loads on the downstream cylinder were determined using the Morison equation. In the fourth scenario, only the downstream cylinder was removed to examine whether loads on the downstream cylinder can be approximated using the Morison equation. Employing an unsteady Reynolds-averaged Navier-Stokes (URANS) equations solver coupled with the volume of fluid (VoF) method, flow velocities were computed at different height positions corresponding to the location of the missing downstream cylinder in scenarios three and four, and these velocities were used in the Morison equation. Flow accelerations were derived from flow velocities using the central difference scheme. These load predictions enabled finding out how well the Morison equation is able to provide useful load predictions even in the presence of wake effects. Wake effects of the front cylinder on the loads acting on the rear cylinder were computed and analyzed. It turned out that maximum impact loads were favorably predicted using the Morison equation, even for the scenario that considered wake effects. However, the timely evolution of these loads after impact differed from comparable measurements.
Hydrodynamic and Mechanic Response of a Floating Flexible Ice Floe in Regular Waves With the ICFD Method
Authors: Behnen Jonas , von Bock und Polach Rüdiger u. Franz , Klein Marco , Ehlers Sören
Published: October 2022

Climate change provides for a stronger wave climate and the open water area in this region will increase. The increase in open water area allows for an increase in higher energy surface waves than previously. In addition, human activities are much more complex in this zone, called Marginal Ice Zone, compared to the open ocean, so that there is an increased research interest in the physical processes of wave-ice interaction and the resulting statements on the influence on maritime technology. This work deals with the development of an efficient simulation environment for the 2D wave-ice interaction on the finite platform LS-DYNA. The numerical model based on the coupled ICFD and implicit structural solvers of LS-DYNA. The motion behavior and the mechanical behavior of the ice floe due to the interaction with different waves are investigated. The stronger wave climate in the Marginal Ice Zone intensifies, making the waves more energetic and increasing the wave steepness. The results of the simulation clearly show that larger wave steepnesses have a large influence on the mechanical stress in the ice floe and the deflection increases. These mechanical stresses lead in the critical cases to a fracture of the ice floe into several smaller ice floes. Consideration of the ratio of ice floe length to wave length showed that the smaller the ratio, the larger the heave and surge movements of the ice floe induced by the waves.
Off-Bottom Plug Placement: On the Effects of Pulling Out of the Hole
Authors: Ghazal Abdallah , Karimfazli Ida
Published: October 2022

Several cement plugs are often placed along cased oil and gas wells, commonly using the balanced-plug technique, to ensure proper abandonment. The placement process starts with the injection of cement slurry into wells that are otherwise filled with lighter wellbore fluids. The injector is pulled out of the hole when the cement slurry is levelled in the injection tube and the annular space between the injector and casing walls (from hereon referred to as POOH). Successful placement is achieved if the plug remains in place after the POOH. In our previous works, we investigated the hydrodynamics of the early stages of the balanced-plug method and provided a mechanistic description of the events that would lead to the accumulation of the injected fluid. In this work, we focus on the hydrodynamics of the final stage of the balanced-plug method. We study the impact of POOH on the lower interface of the injected cement layer. We develop a two-dimensional (2D) model that is representative of the process and conduct numerical simulations, using OpenFOAM, to explore the deformation of the lower interface of the cement plug at different POOH velocities and for different distances between the injector tip and the lower interface of the cement plug.

We show that the injector pullout creates vortices at the injector tip, leaving a trail of vortices within the viscoplastic layer as the injector is pulled away from the interface. Our preliminary results suggest that the interface evolves approximately independently of the injector pullout when the initial distance between the injector and the bottom interface of the cement plug is sufficiently large. Here, the development of instabilities at the interface is reminiscent of the Rayleigh-Taylor instability (RTI) irrespective of the pullout velocity. We show, however, that the injector pullout promotes the mixing of fluids when the interface is close to the injector initially. Reduced POOH velocity appears to enhance the mixing close to the interface.
A Fast and Transparent Method for Setting Powering Margins in Ship Design
Authors: Liu Shukui , Shang Baoguo , Chen Haoliang , Papanikolaou Apostolos
Published: October 2022

The selection of powering margins is a paramount subject in ship design to assure the satisfactory speed performance in ship operation. In this work, the influence of wind and wave on ship resistance is calculated using the methods recommended by ITTC [16]. The influence of fouling on resistance is predicted by the method of Granville [18,19], while the influence of fouling on propeller performance is predicted by the method discussed at ITTC [20]. The seaway conditions are derived by onboard monitored data while the hull and propeller are assumed to be in line with practical observations. All the implemented methods have strong background in theoretical and experimental studies, and are easy-to-use and fast in execution. A case study is presented to demonstrate the methodology. This work is expected to support ship owners, operators, and designers in determining the powering margins in the frame of preliminary ship design.
Numerical Modelling of Wave-Induced Liquefaction Around Pipelines and Offshore Cables
Authors: Kirca V. S. Ozgur , Yilmaz S. Utku , Sumer B. Mutlu , Shanmugasundaram Ranjith Khumar , Rusche Henrik , Windt Christian , Goseberg Nils
Published: October 2022

Submarine pipelines and offshore cables are critical infrastructures for the offshore energy industry. Marine structures like pipelines and offshore cables buried in loose finegrained seabed soil, such as silt or fine sand, maybe under the threat of wave-induced liquefaction. Such failures (flotation or sinking of structures due to liquefaction) have been reported widely in the literature. Observations show that the presence of pipelines/cables can enhance the wave-induced liquefaction susceptibility. This paper presents early results of a numerical modeling study in which the liquefaction potential around a pipeline/cable buried in seabed soil is investigated. A numerical model being developed in the OpenFOAM CFD toolbox under the NuLIMAS (Numerical Modelling of Liquefaction Around Marine Structures) Project is utilized. The results show that the model is capable of simulating the pore pressure buildup around pipelines (or cables), both in near or far field. Additionally, it is shown that different wall boundary conditions of pipelines/cables (i.e. smooth or rough) can be modeled in the numerical model, which is a convenient feature of the model for utilization in practical applications.
Evaluation and Understanding the Potential of Enhanced Oil Recovery for a Candidate Offshore Sandstone Field
Authors: Qi Chuangchuang , Rabbani Aneesa Ijaz , Suboyin Abhijith , Ponnambathayil Jassim Abubacker , Rahman Md Motiur , Haroun Mohamed , Ma Qisheng , Gibrata Muhammad A. , Rouis Lamia , Djanuar Yanfidra
Published: October 2022

The aim of this investigation is to develop a comprehensive understanding of an enhanced oil recovery (EOR) candidate reservoir based in an unconventional sandstone dominated environment. The unique geology, owing to its proximity to an inland, endorheic basin, alongside its complex stratigraphic geometry incorporating extensive folding and faulting as well as a laterally extensive unconformity. The study leans heavily on the forefront of reservoir characterizations.

Reservoir characterization is crucial in providing an outline of the sub-surface and helps visualize the hydrocarbon system in-place. Our study area is the deeper consolidated units. This section was analyzed in detail to understand the petrophysical and fluid properties. The properties of the rock formation(s) of interest were identified from mineralogical content based on XRD analysis and SEM analysis to develop an interlink between the results. A compilation of the results plays a key role in determining reservoir quality and fluid properties which heavily influences important variables such as porosity, permeability, capillary pressure, relative permeability, wettability, interfacial tension, and fluid compositions. The clay mineralogy affects the penetration rate and the diagenetic overprint either enhances or deliberates fluid flow.

The novelty of this integrated study lays the foundation for a thorough and bespoke screening EOR study, which is currently under development for an offshore candidate field. Preliminary screenings were also conducted through core flooding with representative outcrops. An understanding of the integration of the various reservoirs and fluid properties is essential in determining the characteristics of the entirety of the candidate reservoir. Incorporating these complex zones in an integrated reservoir characterization study is fundamental in achieving successful EOR deployment and optimizes oil production.
A Joint-Industry Effort to Develop and Verify CFD Modeling Practice for Predicting Hydrodynamic Coefficients of Risers: Part II – Staggered Buoyancy Module and Straked Riser
Authors: Jang Hyunchul , Agrawal Madhusuden , Huang Zhenjia (Jerry) , Jiang Fengjian , Wu Jie , Lie Halvor , Croonenborghs Eloïse
Published: October 2022

Hydrodynamic force coefficients are important parameters in the design and assessment of marine risers. The hydrodynamic coefficients are widely used for assessing marine riser responses due to floater motion excitation and vortex-induced vibrations (VIV). Traditionally, the hydrodynamic coefficients have been obtained from physical model tests on short rigid riser sections. Recently, the offshore industry has started to use Computational Fluid Dynamics (CFD) analysis for predicting the hydrodynamic coefficients, due to the recent advancement of CFD software and high-performance computing capabilities. However, a reliable CFD modeling practice is required for CFD analysis to be a more widely accepted prediction tool in the industry. A joint industry effort has been initiated for developing and verifying a reliable CFD modeling practice through a working group of the Reproducible Offshore CFD JIP. Within the working group, a CFD modeling practice document was written based on existing practices already validated with model test data and verified by blind validations with three CFD practitioners. The first year work focused on a bare riser with circular cross-section and has been published in OMAE 2021.

This paper presents the working group’s second-year verification activities for a staggered buoyancy module and a straked riser. The verification work covers three numerical test problems: 1) stationary riser in steady current, 2) riser under forced-oscillation in calm water, 3) riser under forced-oscillation in steady current. In the stationary riser simulation, drag coefficient and lift coefficient from verifiers are compared. In the forced-oscillation simulation in calm water, the fully-submerged riser section oscillates with a sinusoidal motion, and damping and added-mass coefficients are compared. In the forced-oscillation simulation in steady current, where the riser oscillates in either inline or perpendicular direction to the steady current, lift coefficient and added mass coefficient are compared. By following the modeling practice, the CFD predictions are consistent with each other and close to the model test data for the majority of the test cases.
Data Assimilation-Based Real-Time Estimation of Downhole Gas Influx Rate and Void Fraction Distribution in a Drilling Riser
Authors: Wei Chen , Chen Yuanhang
Published: October 2022

The ability to perform an accurate estimation of the downhole influx rate and the distribution of the invaded formation gas is of great importance for the modeling of a riser gas event, particularly when the gas kick is to be circulated out through the riser using Managed Pressure Drilling (MPD) systems. Due to the lack of knowledge of the formation pore pressure and the great complexity of wellbore two-phase flow, the influx rate of gas entering the riser is difficult to estimate or direct measure, bringing great uncertainties in the current methods of riser gas modeling. An Extended Kalman Filter (EKF) is used as a Data Assimilation (DA) method for real-time estimation of riser gas influx rate and the enhanced accuracy of the existing physics-based flow models.

Data from a set of full-scale experiments is introduced in this study. A riser gas event in a Water-Based Mud (WBM) system is replicated in the experiments by injecting gas from the bottom of an experimental wellbore. The real-time measurement data, including the surface backpressure, the pressure at the subsea blowout preventer (SSBOP) level, and the liquid outflow rate, are used to estimate the rate of gas entering the riser using the EKF. An online calibrated Drift Flux Model (DFM) implemented with DA is used to estimate the distributed flow parameters, including the profiles of gas void fractions. The gas injection rate measured by a Daniel flowmeter and the downhole Distributed Acoustic Sensing (DAS) data from the full-scale experiments were used to validate the estimation results of the proposed method. Results show satisfying agreement between the estimation and the measurement data.

The benefits of this work are seen in the estimation of the parameters that are difficult to directly measure or control and in the maximized usage of measurement data of different types, realizing the more accurate prediction of gas influx behaviors in the riser. The inclusions of the model online calibration with coefficients adaptively tuned help to further improve the performance of the existing two-phase flow models and help the design of riser gas management strategies.
Influence of Pigging Velocity on the Wax Removal Process in Subsea Pipelines
Authors: Zhang Xun , Huang Qiyu , Chen Wei
Published: October 2022

Wax deposition has been a significant concern in flow assurance. Mechanical pigging is the most common technique used to remediate wax deposition in subsea pipelines. Although researchers have revealed the wax removal process of pipe pigs, it is still unclear whether the pipe pig speed affects the pigging process. Due to a lack of understanding of the wax removal process, the field pigging operation is mainly reliant on empirical rules, resulting in frequent blockage accidents. In this work, the effect of pipe pig speed on the pigging process of cup and disk pigs was investigated using the in-house pigging facility. The experimental results show that the pigging process of both pipe pigs at high and low speeds can be divided into four parts. However, the wax breaking force (WBF) is approximately 2–3 times greater at high speed than at low speed. Also, the WBF of the disk pig is higher compared to the cup pig under the same pigging conditions. The mechanism behind this phenomenon is because of the rheological features of wax deposits. Since the wax deposit exhibits rheomalaxis elasto-viscoplasticity, it is exposed to a larger shear rate at high pipe pig speed, which leads to increased dynamic yield stress of the wax deposit. Furthermore, the difference in WBF between cup pigs and disk pigs results from the geometric characteristics of the pipe pigs. This work can serve as a qualitative guide for on-site pigging operations of subsea pipelines.
The Role of Particle Size Distribution for Fluid Loss Materials on Formation of Filter-Cakes and Avoiding Formation Damage
Authors: Klungtvedt Karl Ronny , Saasen Arild
Published: October 2022

Numerous studies have shown that careful particle size selection is the main parameter for reducing fluid loss when drilling permeable or fractured formations. The methods are generally built around either the D50 or D90 values of the particles in the fluid as a relative size to the pore openings of the formation, to minimise fluid loss.

A series of studies were conducted to measure fluid loss, solids invasion and formation damage. Further, numerical models were developed to describe fluid loss and the build-up of internal- and external filter-cakes with corresponding permeabilities.

It was discovered that different particle size methods should be used for optimising a fluid with regards to reducing fluid loss during the drilling of upper sections of a well than when a drilling fluid is optimized for reservoir drilling and preventing formation damage.

It was concluded that conventional particle size methods were found to be adequate for designing a fluid for wellbore stabilisation purposes. This led to higher solids invasion and a more impermeable internal filter-cake. However, for optimisation of reservoir drilling fluids, a different particle size selection method was found to be more useful to prevent reservoir formation damage. This method involves selecting particles that are resistant towards shear-degradation and with a D90 particle size ⪞ 3/2 the pore size of the formation.
On the Erasing of the Cyclic Preloading by Monotonic Deformations in Granular Soils
Authors: Wappler Andreas , Knittel Lukas , Niemunis Andrzej , Stutz Hans Henning
Published: October 2022

For the design and construction of Offshore Wind Energy Turbines (OWT), it is essential to predict deformations in the subsoil. Wind and waves cause a high-cycle loading on these structures. To ensure their servicability, reliable soil models for predicitions of cumulative displacement over the expected OWT lifetime are needed. In this work, the explicit constitutive High-Cycle Accumulation Model (HCA-Model) by Niemunis et al. [1] has been modified to account for the influence of large monotonic strains on the rate of subsequent cyclic accumulation. In this research project, 21 drained cyclic triaxial tests on saturated, cylindrical Karlsruhe fine sand samples were performed. The packages of cycles were applied on the specimens one after another. Between the packages, the average stress state was monotonically changed. To examine the reduction of the so called cyclic preloading, the tests were analysed regarding the accumulated strain throughout the packages of cycles in each test and the monotonic strain resulting from the change of the average stress state between the packages. In addition, finite-element calculations on an exemplary shallow foundation of an OWT were performed. Two packages of cycles with modification of the cyclic preloading were studied. The reduction of the cyclic preloading was evident.
Global Optimization Workflow for Offshore Drilling Rate of Penetration With Dynamic Drilling Log Data
Authors: Cao Jie , Ren Hui , Sui Dan
Published: October 2022

The prediction and optimization of drilling rate of penetration (ROP) are among the most effective approaches in improving drilling efficiency. To achieve that, it calls for a well-established prediction model and a well-defined optimization methodology. With the advancement in large dataset acquisition and computational efficient machine learning methods, data-driven ROP prediction has superiority over classical physical models. Furthermore, when the ROP prediction model is trained and validated, it can be used to optimize the controllable parameters, preferably globally, given objective functions and proper constraints. The global optimization of drilling ROP is desirable in the design phase, such that the controllable parameters can be optimized for the whole planned well depth. This provides an optimum plan pushing the limit of drilling efficiency and provides valuable controlling strategies that guide the drilling operations.

The main object of this research is to investigate the global optimization workflow for ROP using prediction models based on machine learning methods. We first present an automated data processing method, dealing with and taking advantage of the variety and a vast amount of the drilling dataset. Then, the deep neural network (DNN) model for ROP predictions is validated and tested. In the trained predictive model, there are three controllable parameters, weight on bit (WOB), drilling string revolution speed (RPM), and drilling fluid flow rates (Q). Next, we choose the genetic algorithm (GA) to search the global optimal parameter combination in the control parameters space. The optimization workflow can be applied for the whole well depth, various segments of depth intervals, and different formation layers, resulting in a combination of controllable parameters for the entire well, for every section of given depth intervals, and for each formation layer, respectively. In summary, the global optimization workflow incorporates end-to-end data processing and promotes improved drilling efficiency. The global optimized results push the limit of drilling efficiency and provide valuable post-drilling analysis and offset drilling design recommendations. However, the extreme optimum results may not be reached in field practice, as more constraints such as formation information need to be applied to make the operation realistic.
A Journey From Daily Engineering to Machine Learning, Application to Rigid Pipeline Reel-Laying
Authors: Capelle François-Guillaume , Durand-Gasselin Jonas , Giry Eric , Laye Amandine
Published: October 2022

Digitalisation of engineering analyses has seen a change from limited and time-consuming individual tasks into an organised exercise of automated calculations, sensitivity studies and standardised reporting of results. However, the digitalisation process is not a mere automatisation of the computational activities reducing Engineers to simple “button pushers” but it enables an innovative approach of the design activities that contributes to rise their level of expertise.

An example of implementation of the digitalisation process for the design of subsea pipelines is presented here. The objective is to reduce time spent by Engineers on low value activities and to support comparison, interpolation and presentation of the results to get optimised solutions more efficiently.
Phase Behavior Modeling for Carbon Dioxide/Brine Mixtures Using PR EOS and Huron-Vidal Mixing Rule
Authors: Sun Ziting , Li Huazhou
Published: October 2022

Accurately predicting CO2 solubility in saline aquifers is very important for CO2 capture and storage. A reliable and accurate thermodynamic model is needed to predict the phase equilibrium of the CO2+brine systems over a wide range of temperature, pressure, and molality. In this study, a cubic-EOS-based thermodynamic model is presented to predict the phase equilibrium of CO2+brine mixtures. Peng-Robinson equation of state and Huron-Vidal mixing rule are applied to predict the phase behavior of CO2+brine systems containing salt species including NaCl, KCl, CaCl2, and MgCl2. Binary interaction parameters for specific CO2+single-salt+H2O systems are established as functions of temperature and salt molality. To investigate the impact of multiple salts mixtures on CO2 solubility in brine solutions, the model is extended to CO2+mixed-salt+H2O systems under the practical geological conditions (273–550K, 0–800 bar, 0–6 mol/kg). PR EOS with a modified BIP model in the HV mixing rule is implemented to capture the phase compositions in vapor-liquid equilibria (VLE). The collected experimental data are used to determine the optimal BIP model. Comparison of the experimental data and the computed data indicates that the average absolute deviation (AAD) in reproducing the CO2 concentration in the mixed-salt brine is 0.0015. Compared to other state-of-the-art models in the literature, the new model can more accurately predict the VLE of CO2+brine systems over a large temperature, pressure, and molality range.
Relevance of VPMM: A Survey, Conundrum and Conclusions
Authors: Miller Lakshmi Madhavan , Njaka Taylor , Brizzolara Stefano
Published: October 2022

This study concerns CFD-informed methods to obtain the derivatives of lumped parameters maneuvering models for underwater vehicles. The uncertainty in maneuvering predictions due to the method of obtaining hydrodynamic derivatives is discussed and assessed. Hydrodynamic derivatives are typically obtained from planar motion mechanism tests in both planes. Unsteady RANSE solvers offer the possibility to simulate the same captive steady and unsteady maneuvers to obtain these derivatives by identification procedures. Upon comparing some general representations of such identification procedures, it is found that the values of the estimated coefficient vary due to the method used. The uncertainty affecting the derivatives is propagated onto standard maneuvering predictions. This article discusses the level of uncertainty related to each method and offers insight based on the type of derivatives that vary as well as the type of maneuvers that are affected through the application on two different underwater vehicles. It is observed that there is a recognizable difference in the accuracy and applicability of these methods and a possible way forward is proposed.
Numerical Investigation of Ship Anchor Penetration in Cohesive Baltic Sea Soil
Authors: Dao Duy A. , Grabe Jürgen
Published: October 2022

One of the main reasons for damage to embedded offshore infrastructure is anchor penetration. Sea cables, for example, are harmed either by direct anchor contact or by additional pressure caused by anchor dragging above the cable. A sufficient permanent burial depth is required to minimize the risk of failure due to anchor penetration. This work presents the numerical simulation of the penetration process of two ship anchors (HHP AC-14 and Spek) in cohesive soil of the Baltic Sea. The simulations are carried out using the Coupled Euler-Lagrange (CEL) method in Abaqus/Explicit. Baltic Sea silt, under undrained conditions, is modeled. For the creep, relaxation behavior, and velocity dependence of the soil, the visco-hypoplastic constitutive model, according to [1], is used. Soil parameters have been obtained by laboratory tests. A parametric study is conducted varying anchor type, mass, and velocity, which significantly influence penetration depth and penetration behavior.