bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nanotechnology-Based Solution for Offshore Zinc Removal Water Treatment Technology
Authors: Ventura Darryl , Murugesan Sankaran , Kuznetsov Oleksandr , Mazyar Oleg , Khabashesku Valery , Darugar Qusai 
Published: April 2017

Abstract
This paper discusses the synthesis of hybrid carbon nanotube (CNT) and carbon nitride (CNx) membranes for applications in flowback water filtration processes. Due to their intriguing properties, these nanocomposites may be a suitable replacement for conventional membranes found in spiral-wound filter cartridges. The membranes presented here offer a dual-filtration mechanism because nano-sized particulates are filtered out by the porous, high-surface area CNT membrane while charged ions are removed via the CNx particles. This membrane has also demonstrated a unique ability to bind to, and subsequently filter out, divalent ions such as zinc—a common component of completion fluid. In addition, the inherent physical properties of CNTs, such nanocomposites, offer enhanced chemical corrosion resistance and anti-fouling properties.
Shallow Gas and Shallow Water Flow Induced by Natural Gas Hydrate Dissociation in Deep Water Sediments
Authors: Gong Zhiwu , Ren Shaoran , Zhang Liang , Cui Guodong , Liu Yanmin , Wang Yanyong 
Published: April 2017

Abstract
A heat transfer model in NGH sediments during drilling fluid deep-circulation and a dynamics model of NGH decomposition, in which the temperature-difference driving process is mainly considered, are established to evaluate NGH dissociation and gas and water production during deep-sediment penetration. A local overpressure generation model from NGH dissociation is constructed to calculate the induced overpressure and shallow gas (SG) and shallow water flow (SWF) formation under various conditions. Investigated are the effects of drilling fluid circulating temperature and NGH saturation on NGH dissociation and overpressure (SG and SWF) formation processes. The results indicate that the heat conduction from circulating drilling mud to NGH formation is so slow that local overpressure will only be developed within about 1.5m around the wellbore for 9 days of drilling fluids deep-circulation under typical operation conditions. For the typical NGH bearing sediment, an overpressure as high as 2.4MPa will be induced within the formation about 1.5m around the wellbore after about 9 days of drilling fluid deep-sediment circulation. This will exert great threat on the safety of cement sheaths and NGH sediment caps. During deep-sediment penetration and drilling mud circulation, the NGH saturation has more significant effects on NGH decomposition and local overpressure development than mud circulating temperature. 100% increase of drilling mud circulating temperature will result in only 10% increment of the local overpressure around the wellbore, while 100% increase of NGH saturation will result in 130% augment of in-situ overpressure.
Smart Bentonite Drilling Muds Modified with Iron Oxide Nanoparticles and Characterized Based on the Electrical Resistivity and Rheological Properties with Varying Magnetic Field Strengths and Temperatures
Authors: Vipulanandan C. , Mohammed A. , Samuel R. G. 
Published: April 2017

AbstractIn this study, the effects of magnetic field strength and temperatures on the electrical resistivity and rheological properties of a sensing smart bentonite drilling mud modified with iron oxide nanoparticles (nanoFe2O3) were investigated. The bentonite contents in the smart drilling muds were varied up to 6% by the weight of water, and the temperature was varied from 25°C to 85°C. The magnetic field strength was varied up to 0.6 T. The nanoFe2O3 contents (particle size of 30 nm and surface area of 38 m2/gm) in the drilling muds were varied up to 1% by the weight of drilling mud to enhance the sensing electrical resistivity and the rheological properties of the drilling mud. The initial resistivity of the 2% and 6% bentonite drilling mud were 9 Ωm and 5.5 Ωm, a 39% reduction in resistivity, a good sensing property.The electrical resistivity of the drilling mud modified with of nanoFe2O3 decreased by 15% to 50% based on the nanoFe2O3 content, temperature and magnetic field strength. The rheological properties of the drilling muds were characterized by high strain rate to determine the nonlinear behavior of the shear thinning drilling mud. Based on the new Vipulanandan rheological model, the yield stress (o2) of the modified drilling mud increased by 6% to 100% depending on the bentonite content, nanoFe2O3 content, temperature and magnetic field strength. Based on the Bingham plastic model the plastic viscosity of the modified drilling mud were increased by 50% to 90% based on the bentonite content, nanoFe2O3 content, temperature and magnetic field strength. The shear thinning behavior of the drilling mud with and without nanoFe2O3 has been quantified using the Vipulanandan rheological model and compared with the Herschel-Bulkley model. Based on the Vipulanandan rheological model the maximum shear stress produced (maximum shear stress tolerance) by the 2% bentonite drilling mud modified with zero and 1% of nanoFe2O3 at the temperature of 25°C with no magnetic field strength were 26 Pa and 64 Pa respectively. Increasing the magnetic field strength to 0.6 T increased the maximum shear stress produced by the 2% bentonite drilling mud modified with 1% of nanoFe2O3 at the temperature of 25°C to 80 Pa, a 25% increase. With the 6% bentonite drilling mud the trends were similar but the magnitude of the maximum shear stress produced was almost doubled. The rheological properties of the drilling mud modified with nanoFe2O3 under different magnetic field strength have been correlated to the electrical resistivity of the drilling mud using the three parameter Vipulanandan property correlation relationship.
Recent Advances in Nonlinear Soil Models for Fatigue Evaluation of Steel Catenary Risers SCRs
Authors: Clukey Edward C. , Zakeri Arash 
Published: April 2017

Abstract
The role of soil response on fatigue life of Steel Catenary Risers (SCRs) has been investigated through a scaled sectional SCR (cut-out section) in a geotechnical centrifuge. The SCR model simulated a section of the SCR starting at 16 ft (4.9 m) above the seafloor and extending approximately 360 ft (~110 m) through the touchdown region to the anchor point. The centrifuge tests were successfully performed using soils from the Gulf of Mexico (GoM) and offshore Angola. Past studies have demonstrated that fatigue damage in a full-scale SCR at touchdown zone can accurately be modeled using a scaled sectional SCR in a geotechnical centrifuge. The centrifuge results were compared to finite element simulations with the seabed response modeled using nonlinear springs derived based on unload-reload stiffness (secant stiffness) of degraded soil at steady-state conditions. This resulted in development of a simplified approach involving the nonlinear soil springs. Fatigue analyses indicated that this simplified approach can predict fatigue damage as measured in the SCR centrifuge tests. Centrifuge tests were also performed to determine the impact of trench depth on SCR fatigue. The tests involved a flat seabed and seabed with an initial prescribed trench. SCR fatigue damage in the test with an initial prescribed trench was similar to that of the flat seabed; however, the critical fatigue point had significantly shifted.
Hazard Quantification of Seismically Induced Tsunamigenic Subaerial/Submarine Mass Movements
Authors: Sancio Rodolfo , Rao Pramod , Hunt Christopher , Umberg David , Greene Alexander , Misra Shubhra 
Published: April 2017

Abstract
This study presents a simplified framework for the quantification of the probability of seismically induced subaerial and submarine mass movements, an essential input for assessment of tsunami risk. The study incorporates the probability of seismically-induced ground motions developed from a Probabilistic Seismic Hazard Analysis (PSHA) and the probability of landslide triggering given an input ground motion, to calculate the joint probability of seismically-induced mass movement.
Potential subaerial and submarine sliding masses of sufficient size to trigger a tsunami were identified through a geomorphological analysis of seafloor bathymetry and topographic relief coupled with available regional geological studies of the area. Typical slide volumes were in the range of 107 and 108 m3, consistent with the volumes noted during historical events.
In this study, the probability of triggering a mass movement was defined as the probability of exceeding a threshold seismically-induced displacement value along a defined sliding surface beyond which uncontrolled movement of the slide mass was assumed to occur, leading to the potential development of a tsunami wave. The probability of exceeding the threshold displacement was calculated using the Bray and Travasarou (2007) method for estimating earthquake-induced slope displacements.
The study treated uncertainty in the input parameters through the use of probability density functions developed using slope stability back analyses and engineering judgement. Material strength parameters were subsequently updated using Bayes theorem.
The results of the study indicated that seismically-induced mass movements with potential for triggering a tsunami wave would have an annual probability lower than 1·10−3. Some of the slide scenarios selected in the study were used by others as input into hydrodynamic analyses for tsunami wave generation and propagation, and subsequently to define design inundation levels and design wave events for marine facilities.
Cross Sectional Flow Modelling of a Drilling Riser System for Hydrodynamic Drag Consideration
Authors: Lai Lawrence S. H. 
Published: April 2017

Abstract
This study aims to characterize the hydrodynamic behavior of top-tensioned drilling riser joints with complex cross-sectional profiles when exposed to offshore current environments, such as slick joints and conventional buoyant joints. Computational Fluid Dynamics (CFD) has been employed to analyze these component cross-sectional profiles and define the component drag coefficients (Cd) and lift coefficients (Cl). These coefficients determine the riser external loading, which in turn affects the riser internal stresses. The Strouhal number St is also calculated which characterizes vortex shedding.
Validation of the CFD model is performed based on 2-dimensional flow past a cylinder. Following this, 2-dimensional representations of the detailed drilling riser components are created. The flow speed range considered corresponds to prevalent offshore environments, with Reynolds number (Re) = 105 – 106. The average forces are determined by subjecting the riser to various flow angles of attack across the 360 degrees range, giving the Re-dependent Cd and Cl. Variations in vortex-shedding is also analyzed by calculating St to demonstrate the effects of different flow attack angles.
Validation of Cd and St for flow past a circular cylinder show good agreement with literature. Variation of the riser component outer profile and flow attack angle show variation in the drag and lift force experienced as well as the vortex shedding behavior. More accurate Re-dependent Cd was produced for the various cross-sections analyzed that could be used in subsequent global riser analysis to simulate the full connected system from vessel, riser system, wellhead, and conductor and casing (interacting with the seabed).
Application of these more accurate drag coefficients result in more representative riser motions and loads in the global riser analysis. The benefit is potentially increasing vessel and operational uptime, and accurately calculating the drilling riser system fatigue life. Ultimately, this enables drilling operators and their stakeholders to make better-informed decisions on their offshore operations.
Design Methodology for Converting a MODU into a FPU
Authors: Moe Anders Martin , Laranjinha Manuel 
Published: April 2017

Abstract
There are many idle mobile offshore drilling units (MODU) that present potential opportunities to reduce the cost of field development. This paper summarizes the background and proposes a design methodology that can be applied when companies look into the potential of modifying semisubmersible MODUs to floating production units (FPU).
The focus will be on the relevant commercial aspects that need to be taken into account, followed by the engineering efforts required for modification of the hull and main marine systems and the replacement of drilling systems by process topsides. There are some key differences in the design drivers for semisubmersible MODUs and FPUs that need to be taken into account when considering a conversion. This further governs the requirements for modifications and upgrades of a semisubmersible MODU in order to operate as a FPU. Based on the above, a case study has been executed.
Expected required modifications and upgrades are outlined in the paper. Further, some options for improving payload capacity are presented and discussed in terms of cost, payload increase and overall impact on the FPU design. There are several technical and commercial aspects that affect the viability of converting semisubmersible MODUs to FPUs, including but not limited to: production capacity/profile, environmental conditions, existing infrastructure, mooring and riser system requirements, contractual model, CAPEX for MODU and conversion scope. On the basis of the above, and an overall assessment of the current market and availability of MODUs, a qualitative feasibility evaluation has been performed and is presented in the paper.
The need to reduce the cost of deepwater projects is vital if projects are to be sanctioned and move forward. We must find innovative ways to drive out cost if the industry is to survive. Conversion of MODUs to FPUs may prove to provide an opportunity to achieve this.
DeepStar® Study on Effect of Coupled Horizontal and Vertical Interaction of Steel Catenary Risers with the Seabed within the Touchdown Region
Authors: Sancio Rodolfo B. , Clukey Edward C. , Lekkakis Dimitris , Aubeny Charles 
Published: April 2017

Abstract
Steel Catenary Risers (SCR) are typically subjected to vertical and horizontal motions, as well as rotations, causing the SCR to interact with the seabed within an area described as the Touch Down Zone (TDZ). The interaction between the seabed and the riser at the TDZ induces bending stresses on the SCR that can have a significant impact on the fatigue life of the riser.
ROV surveys of installed deepwater SCRs show that, in soft clayey seabeds, SCRs cut deep and wide trenches into the seabed that are up to four or five pipe diameters deep and three to four pipe diameters wide. Despite the observed lateral interaction between the seabed and the SCR, the current standard of practice for fatigue analysis of SCRs, through commonly used design software packages, only considers the vertical interaction of the SCR with the soil in the TDZ, thus neglecting the effect of the lateral interaction between the SCR and the seabed and its potentially detrimental effect on the fatigue life of the riser.
A study was commissioned as part of DeepStar® Phase X to evaluate the effect of horizontal interaction between the seabed and an SCR. Quasi-static analyses were conducted using a finite element method based program by simplifying the interaction of the SCR and the sea bed as that of a beam resting on, and surrounded by, linear and non-linear springs. The von Mises stress range was calculated for conditions in which the SCR was subjected to vertical motions and to vertical and horizontal motions while varying: (1) the amplitude of the motion; (2) the undrained shear strength of the sea bed; (3) the initial embedment of the riser in the seabed; and (4) the boundary conditions applied to the SCR.
The results of our analyses indicate that, for the conditions that were studied, the effect of incorporating horizontal interaction between the SCR and the sidewalls of a trench on the von Mises stress range is typically less than 5%. The analyses also indicate that: (1) the effect of the lateral interaction of the SCR with the seabed increases as the amplitude of the vertical and horizontal motions increase; (2) the contribution of the lateral motion decreases as the soil strength increases and the soil stiffens; (3) the contribution of the lateral motion decreases as the embedment depth increases.
This simple study showed that horizontal seabed-SCR interaction may not have a substantial effect on the fatigue life of the SCR. However, other sea states, soil conditions, and geometries may show substantially different results that should be investigated.
The Dawn of the New Age of the Industrial Internet and How it can Radically Transform the Offshore Oil and Gas Industry
Authors: Sharma Partha , Hamedifar Hamed , Brown Aaron , Green Richard 
Published: April 2017

Abstract
Rapid advancements in big data management, digital connectivity, low-cost sensor technologies and high-performance computing, are ushering in the fourth industrial revolution: the Industrial Internet. This paper provides an overview of the Industrial Internet and the infrastructure implementation challenges for the offshore oil and gas industry.
The application of the Digital Twin for Asset Performance Management and Real-time Facility Risk Management is described in the paper. The Nauticus Twinity use case for performance management of a supply vessel demonstrates the benefits of a digital twin. Finally, the paper elucidates the challenges of implementing machine learning models in operations to improve asset performance.
Standardization Benefits for Megaprojects, Illustrated by Motor and Drive Case Studies
Authors: Ward Stephen , Jackson Eur Ing Steve 
Published: April 2017

Abstract
This paper discusses standardization benefits for megaprojects drawing on first hand experiences from actual executed global projects and the collected opinions of End Users and Engineering Procurement Contractors (EPCs).
Megaprojects are characterized not only by their huge scale but also through the many global parties required to execute and the number of partners involved in funding and finally operating the constructed enterprise. All these relationships mean difficult agreements on preferred vendors and specifications which can lead to multiple competitive bids to satisfy perceived ‘lowest' cost requirements. However, some studies have indicated that an additional 100% man hours is spent on engineering products to meet special project specifications rather than use industry standards. This is compounded when these particular project requirements have to be enforced across a number of different vendors for similar equipment. Consequently there is an industry-wide trend towards simplification and standardization not only to a small number of vendors on a project, but also to use as close to accepted industry and vendor norms wherever possible.
Supplying motors and drives to global oil and gas, megaprojects is a complicated business because the equipment is not purchased directly by the EPC or the End User. Typically motors and drives are packaged by the compressor, pump, fan, hoist, HVAC etc. Original Equipment Manufacturers (OEMs) who may be myriad in number and located in various other different countries. Standardization provides significant CAPEX and OPEX benefits as well as reduce risk and man hours during project execution. In some cases it has been calculated to save as much as 14% of the total motor and drive project spend.
The Main Motor and Drive Contractor (MMDC) methodology has been used successfully to provide simplification, standardization, reduced cost, less effort, fewer interfaces and lower risk on a number of megaprojects.
AC Subsea Power Transmission Architectures, Design And Challenges, The Martin Linge Case
Authors: Skaanoey Thomas , Kerin Uros , Van Luijk Nico , Thibaut Edouard 
Published: April 2017

Abstract
The development in subsea technology relies increasingly on sophisticated and power-intensive equipment, such as pumps, compressors, processing, and flow assurance systems, for which there is a growing need to provide ultra-reliable electrical power transmission, distribution and conversion systems in order to supply subsea processing equipments through long step-outs.
In May 2015, the 163km long Martin Linge submarine cable was successfully energised and tested, setting the world record for the longest High Voltage AC (HV AC) subsea cable. This key achievement has demonstrated the feasibility and maturity of AC subsea power transmission for long stepouts. The next technical challenge would be to develop and mature a concept where the full field development is made subsea, whilst using power from shore through a long AC step out.
This paper provides an overview of potential architectures for long step-out subsea electrical power transmission and distribution systems. The paper describes the design and main technical challenges of the Martin Linge AC transmission step-out. Finally, the paper provides an insight in the point of view of the manufacturer and operator, with lessons learned in a successful development of a power from shore solution.
Cleanup of Organic and Inorganic Wellbore Deposits Using Microemulsion Formulations: Laboratory Development and Field Applications
Authors: Quintero Lirio , Ponnapati Ramakrishna , Felipe Mary Jane 
Published: April 2017

Progressive reduction of the flow path of oil and/or gas in the near-wellbore region could cause a gradual decline in hydrocarbon production. The major parameters that influence the time-frame of this process are related to the properties of the crude oil and to the reservoir pressure and temperature. Failure to achieve expected well production could also occur, suddenly, after a well intervention or after the wellbore construction. In either case, changes in pressure, temperature, fluid composition, incompatibility of fluids and/or poor fluid-rock interaction can generate precipitation and deposits of asphaltenes and paraffins, scale formation, emulsions or sludge and wettability alteration.
In general, traditional treatments do not target all possible causes of crude oil flow-path reduction at the same time, and a sequence of treatment fluids are pumped to clean up the multiple damages (e.g., treatment of organic deposits followed by an acid treatment to remove scale deposits). The long cleanup time and high volume of fluids used in a multi-step treatment could impact the economics of the projects, especially offshore.
The present work discusses multifunctional treatments for production enhancement and flow assurance that can remove organic deposits (e.g., paraffins and asphaltenes), emulsion blockage, scale deposits and increase water-wet condition of the flow path surfaces in one step.