bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical Simulations of High CO2 Content Flows in Production Wells, Flowlines and Risers
Authors: Carneiro J. N. E. , Pasqualette M. A. , Reyes J. F. R. , Krogh Espen , Johansen S. T. , Ciambelli J. R. P. , Rodrigues H. T. , Fonseca R. 
Published: October 2015

Abstract
There are several challenges associated to the pre-salt development at the Santos basin, such as long distances from the coast, low temperature reservoirs, high pressures, high water depth, among others. Additional aspects contributing to the complex production scenario are related to fluid characteristics and flow assurance. In particular, the high CO2 content in the dissolved gas is an important characteristic that should be also analyzed, because CO2 is not only a heavy component, when compared to lighter components present in the gas phase, but has also a high Joule-Thomson coefficient. This affects pressure drop and specially the mixture cooling behavior during decompression. The cooling effect is expected to be strong at high production rates. Thus, the objective of the present work is to evaluate these effects under present and future production scenarios, taking into account increasing CO2 contents due to re-injection strategies.
Two different field configurations were investigated and a variety of operating conditions was used, along with real and model fluids ranging from 5% to 50% CO2 content (molar basis). PVT data for the model fluids with high CO2 content were generated by a simulated swelling test with CO2 of an existing mixture with lower CO2 content. A parametric study was carried out aiming at investigating primarily the total pressure and temperature drop in the pipeline when the total CO2 content of the mixture is increased. Furthermore, variation of the fluid properties along the well, flowline and riser was evaluated. Results are also discussed in view of the impact of increasing CO2 contents and the challenges experienced during simulation of such flows.
Anti-Slug Advanced Control for Offshore Production Platforms
Authors: Campos M. , Meien O. , Neto S. , Stender A. , Takahashi T. , Ashikawa F. 
Published: October 2015

The application of advanced control techniques in offshore oil production plants is a challenge. There are many changes in operational points in time, for example, the process is affected by the natural oil well's behavior dynamics. Besides that, limited instrumentation available has to be considered when thinking in oil optimization and control. In order to improve the scenario, taylor-made advanced control modules have been developed for those units. The present article will present development, implementation and results of anti-slug control for four platforms located at Campos and Santos basins. Severe slugging flow regimes are one of the major disturbances for the operation of offshore production platforms. Slugs can occur, for example, in pipeline-riser systems that transport oil and gas mixture from the seabed to the surface and they are characterized by severe flow and pressure oscillations, with moments of high instantaneous liquid or gas flow, which is then followed by moments of almost no flow. This cyclical phenomenon can cause many problems like reduction in process efficiency, and production losses due to many unplanned shutdowns.
One of the ways to minimize issues associated with slugs is to use advanced control techniques in wells. These techniques utilize the available measurements, as downhole pressure (PDG) and top side pressures, to define a choke valve position that minimize or even eliminate slug instability. The objective is to have a stable flow together with the maximum possible production rate. One great challenge for this anti-slug control is how to deal with plant nonlinearity, because the process gain of the system changes drastically at different operating conditions. So, we will discuss in this paper different control algorithms to deal with this problem.
This paper will present an anti-slug advanced control, which has three subsystems: one responsible to diagnose and identify slugs, considering some pressures patterns; other to control or minimize slugs; and finally one to protect the process plant in case of severe disturbances. Finally, this paper will show and discuss some economic and safety results of the implementations of these anti-slugs advanced control systems in offshore platforms, emphasizing the benefits obtained, which are related with stability, energy efficiency, and profitability due to a important decreasing in unscheduled compressor shutdown events, as well as increasing in operational efficiency. It will be shown that operators have well accepted this system and are maintaining this controller in automatic mode in more than 80% of the operating time.
Offshore Waste Water Management System Reduces Operating Costs
Authors: Usher M. , Herrington D. , Kozikowski M. , Scott E. 
Published: October 2015

Regulatory constraints governing the discharge of contaminated waste water in offshore operations are increasing across the world. In most regions, contaminant (oil) levels above 30 mg per liter are strictly monitored and regulated to protect our environment. These regulations prohibit disposal of contaminated material offshore, forcing this "slop" water to be transported from the rig to shore for proper treatment and/or disposal. The costs associated with transport, handling, and disposal are incremental to the drilling operations and drive up the cost of the well. These additional rig and logistical operations further expose rig personnel to potential health and safety risks by burdening the crew with additional activity and movement of materials. The intent of this paper is to show the performance capabilities of an innovative waste management system that has been proven capable of reducing the slop water volumes in offshore operations by as much as 80%.
A novel waste management system has been developed and designed specifically to reduce the costs associated with offshore waste water management. The technology has been performance tested to prove that it can efficiently remove the contaminants required to allow clean permeate to be discharged to sea. Testing conducted to confirm system capabilities utilized genuine offshore slop water at various levels of contamination. Waste contents tested ranged between 1% and 10% and were comprised of both oil and solids.
Performance testing has been successful for over one year with no visible suspended solids detected in the resulting permeate. All concentrations tested showed the quality of permeate produced to be below the 30 mg/liter oil in water threshold, qualifying it for discharge to sea. Additionally, the reliability and maintenance needs of the system were benchmarked to confirm operational efficiency and cost requirements.
The system's performance has shown the ability to significantly reduce the volume of waste/slop water that would otherwise have to be transported to shore and treated/disposed of as prescribed by regulatory agencies. The system's ability to remove these contaminants directly results in reductions as high as 80% in the volumes being shipped to shore for treatment and disposal and consequently a significant reduction in disposal and handling costs.
Considerations of Adjusted Brine Chemistry for Waterflooding in Offshore Environments
Authors: Alvarado V. , Garcia-Olvera G. , Manrique E. J. 
Published: October 2015

AbstractThe work addresses technical issues of waterflooding operations in offshore environments from the standpoint of fluid-fluid and rock-fluid interactions. Seawater is the preferred source of injection fluid for waterflooding in offshore reservoirs. Given the elevated CAPital EXpenditure (CAPEX), seawater treatment is generally driven by the need to mitigate injectivity loss or water compatibility issues such as the formation of hard scales. The emergence of engineered water as an enhanced-oil recovery (EOR) process has prompted the need to adjust seawater chemistry. Water chemistry modification, however, is a reservoir specific process in our view. Here, we analyze fluid-fluid as well as rock-fluid interactions for two heavy-oil carbonate reservoirs in the Gulf of Mexico to show that geochemical interactions upon adjustment of brine chemistry can lead to undesirable results depending upon lithological characteristics.Crude oils from two offshore carbonate reservoirs in the Gulf of Mexico were used in experiments. Synthetic reservoir brine was prepared based on produced water analysis. Shear and dilatational rheology were employed to estimate interfacial moduli of crude oil-brine systems, for several water chemistries. These dynamic interface properties have been found to contribute to EOR mechanisms in low-salinity waterflooding. Three different carbonate outcrop samples were used to characterize single-phase rock-fluid interactions in coreflooding experiments. Effluent samples were collected to determine cations and anions concentrations and thereby calibrate geochemical models. We contrasted the needs of seawater modification with availability of viable technologies for offshore operations, such as reverse osmosis, to envision feasible optimization of brine chemistry.Results show that geochemical interactions upon modification of equilibrium conditions in reservoirs resulting from injection of adjusted brine chemistry can lead to in situ alteration of water chemistry in a way that it impairs EOR benefits of adjusted brine chemistry injection. This is particularly severe when low-ionic strength is selected for injection in anhydrite-containing carbonate reservoirs. On the other hand, current sulfate-reducing strategies to avoid scaling in sandy reservoirs run contrary to proposed sulfate-enrichment in several oil-producing provinces. Current technologies appear to enable a broad spectrum of water chemistry modification, but implementation in offshore environments might be prohibitive for some designs.The combination of experimentally calibrated geochemical modeling with interface rheological characterization, in light of current seawater treatment technologies, offers a novel strategy to guide optimum water design for adjusted brine chemistry waterflooding operations.
CFD Simulations of Multiphase Flows Containing Large Scale Interfaces and Dispersed Phases with Selected Production Technology Applications
Authors: Johansen S. T. , Mo S. , Meese E. , Oliveira J. E. S. , Reyes J. F. R. , Carneiro J. N. E. 
Published: October 2015

Abstract
Multiphase flows in oil- and gas pipelines involve a variety of different flow regimes. The different flow regimes are determined by the geometric arrangement of oil, gas and water inside the pipe, and evolve in a dynamic manner along a flowline, from bottom hole to receiving facilities. Along the path of the flow, the geometric fluid arrangements (or flow patterns), which develop dynamically, are often outside what is properly accounted for in existing 1D flow models. In such cases, more detailed multidimensional models are needed. As the industry is facing tighter operating margins and stricter regulatory frameworks, more accurate and predictive tools are needed. It is realized that CFD (Computational Fluid Dynamics) type models cannot replace 1D models in most cases, but will be an extremely valuable addition to the toolbox in cases where the 1D models may be insufficient.
In the present paper a CFD method will be presented which enables such generic simulations. In this model, the physics of coexisting large scale interfaces and dispersed fields (droplets and bubbles) has been handled. Results obtained by a "Quasi-3D" implementation of the model will be shown for a number of important industrial applications. It will also be shown how such tools can also be applied to improve existing 1D frameworks, or directly to tackle multiphase production technology challenges.
Field Results of the First Brazilian Pre-Salt Multi-Fractured Sub-Horizontal Well
Authors: Azevedo C. T. , Neumann L. F. , Denadai N. J. , Chagas C. M. 
Published: October 2015

Petrobras pre-salt discovery is a huge hydrocarbon reserve located below an extensive layer of salt at about 5000 m depth. So far, the wells drilled at this scenario found light oil in highly heterogeneous carbonates reservoirs. The formation permeability varies more than four orders of magnitude. Some fields have most of the permeable zone with values ranging from 1 to 10 mD and this scenario requires stimulation in order to maximize productivity. This article will present the first multi-fractured sub-horizontal well constructed in the pre-salt reservoir.
In this stimulation operation 8 acid fractures were created in a sub-horizontal open hole well. This article will show the completion selected that permitted to register the bottomhole data above and below the zone where the fracture was being created. This record allowed the interpretation if the fractures were really created in the zones selected or if there were communication between zones. The article will present the calibration tests results, the fracturing data of all intervals and some insights regarding fracture orientation due to temperature behavior.
The reservoir depth and the proximity of the salt layer bring many challenges regarding hydraulic fracturing operations. This operation and other field results have shown minimum in situ stresses in the magnitude of 0.7 psi/ft and fracture propagation pressure that exceeds the estimated overburden. The records of the bottomhole pressure during this operation showed that there were some communication between zones. After the stimulation operation, a formation test was done measuring the well productivity and collecting samples of the reservoir fluid. The samples collected were analyzed and the tracers used during the stimulation were identified, indicating which fracture was contributing to production. The data registered during this operation is a huge lesson learned about doing multi-acid fractures in a carbonate reservoir for all the industry.
Overview of CFD Multiphase Flow Simulation Tools for Subsea Oil and Gas System Design, Optimization and Operation
Authors: Gharaibah E. , Read A. , Scheuerer G. 
Published: October 2015

Due to the recent drop in the oil prices, the oil and gas industry is experiencing tremendous pressures to reduce costs. This is especially true for both Subsea Production Systems (SPS) development and operations to ensure profitability while meeting increasing regulatory requirements.
In the last years, the modelling and simulation of multiphase flows has become a powerful engineering tool to conduct virtual experiments during design and development for many industries, such as aerospace, automotive, energy and healthcare. This is mainly due to the significant improvement of the modelling approaches which include more details of multiphase flow physics and phenomena. An additional growth contribution is due to the rapid development of the computational resources and computer power.
The oil and gas industry can benefit from high fidelity multiphase flow modelling and simulation tools to minimize the cost of production system design during the project development phase as well as to support optimized operation and assessment of production performance. Because of the low-risk virtual environment, the use of multiphase flow modelling and simulation tools will also reduce the cost of physical testing, assist development of new technologies, and the evaluation of novel concepts.
The objective of this paper is to provide an overview of the state-of-the-art of multiphase flow simulation tools and their recent evolution and adaptation for subsea applications. The focus is on multiphase flow modelling using Computational Fluid Dynamics (CFD) simulation tools, and in particular on their capabilities and limitations when applied to predict the hydrocarbons behavior throughout their journey from the reservoir to the processing facility. Applications of multiphase CFD tools to support the design, operation and monitoring of SPS and the developments and validations required for replacing costly laboratory tests, component qualification and field tests are also addressed and discussed.
Impact of Notch1 Deletion in Macrophages on Proinflammatory Cytokine Production and the Outcome of Experimental Autoimmune Encephalomyelitis
Authors: Wongchana Wipawee , Lawlor Rebecca G. , Osborne Barbara A. , Palaga Tanapat 
Published: October 2015

Abstract
Notch signaling is involved in regulating TLR-mediated responses in activated macrophages. In this study, we investigated the impact of Notch signaling in macrophages in an experimental autoimmune encephalomyelitis (EAE) model. To examine the impact of deficiency in Notch signaling in activated macrophages in EAE, an adoptive transfer of activated macrophages derived from Notch1fl/fl × Mx1cre+/− (Notch1 knockout [N1KO]) or CSL/Rbp-jκfl/fl × Mx1cre+/− (CSL/RBP-Jκ KO) mice was performed prior to induction of EAE. Mice receiving activated N1KO macrophages showed decreased severity of EAE compared with mice receiving wild-type or CSL/RBP-Jκ KO macrophages. In vitro restimulation of splenocytes by myelin oligodendrocyte glycoprotein 35–55 peptide from these mice revealed that cells from mice receiving N1KO macrophages produced significantly less IL-17 compared with the control mice, whereas IFN-γ production was similar in both groups. We found that activated N1KO, but not CSL/RBP-Jκ KO, macrophages produced less IL-6 and had lower CD80 expression compared with wild-type and did not exhibit any defect in IL-12p40/70 production, whereas activated macrophages from CSL/RBP-Jκ KO mice phenocopied γ-secretase inhibitor treatment for reduced IL-12p40/70 production. Furthermore, the nuclear translocation of the NF-κB subunit c-Rel was compromised in γ-secretase inhibitor–treated and CSL/RBP-Jκ KO but not N1KO macrophages. These results suggest that Notch1 and CSL/RBP-Jκ in macrophages may affect the severity of EAE differently, possibly through modulating IL-6 and CD80 expression, which is involved in the Th17 but not Th1 response.
Métodos de entrenamiento de las habilidades espaciales de los estudiantes de titulaciones técnicas
Authors: Mataix Sanjuán Jesús , León Robles Carlos , Reinoso Gordo Juan Francisco 
Published: October 2015

<p>Las habilidades espaciales son herramientas fundamentales en el desempeño profesional y en la formación académica de ingenieros y arquitectos. Sin embargo los sucesivos planes de estudio, en particular los derivados del Espacio Europeo de Educación Superior, asignan cada vez menos créditos para las asignaturas de Expresión Gráfica, lo que conlleva una insuficiente atención al desarrollo de estas habilidades.</p><p>Ante esta situación, desde el ámbito de la docencia de la Expresión Gráfica se han llevado a cabo en las últimas décadas numerosos estudios que analizan varios métodos entrenamiento de las habilidades espaciales. Este artículo describe algunos de los principales estudios y sus resultados, de los que se desprende que son los ejercicios de bocetado a mano alzada los más eficaces, por encima del modelado con aplicaciones CAD y de herramientas innovadoras y software específicamente diseñado para ello.</p>
Descripción y análisis geométrico del templo parroquial de Santa María la Antigua de Zumárraga (Guipúzcoa)
Authors: Ayerza Elizarain Ramón , Mujika Marte 
Published: October 2015

La población guipuzcoana de Zumárraga conserva, por felices coincidencias, su primitivo templo parroquial tardogótico de madera. Su análisis geométrico ha puesto de manifiesto el alto nivel de especulativo de su diseño arquitectónico y la extraordinaria coherencia de su sistema de proporciones.
Art Teachers’ Beliefs about Creativity
Authors: Stone Denise L. 
Published: October 2015

AbstractArt teachers hold beliefs about creativity, including the process, ways to enhance it, and what personality traits are typically associated with it. These notions influence daily decision making, shape instruction, and affect student mentoring. Even seemingly simple decisions, such as selecting student products for display on a bulletin board, to more significant deliberations about juried art competitions are affected by creativity beliefs. The present study investigates art teachers’ implicit theories about the topic, that is, how they define it, support it in the classroom, and view creative traits of their students. A questionnaire consisting of 14 items was sent to 319, K-12 art specialists teaching in urban, suburban, and rural districts in a midwestern state. The survey was electronically administered to a sample of 319 teachers; a total of 93 replied, yielding a response rate of 32%. The results suggest that teachers’ beliefs aligned with the perspectives of both idealistic and action theorists of the field of psychology. Their ideas were somewhat contradictory and unproductive, in light of the needs of contemporary art education. It is suggested that educators in the study did not receive pre-service training that included general information and procedural knowledge for promoting creativity in the art room.
Quantifying Residues from Postharvest Propylene Oxide Fumigation of Almonds and Walnuts
Authors: Jimenez Leonel R , Hall IV Wiley A , Rodriquez Matthew S , Cooper William J , Muhareb Jeanette , Jones Tom , Walse Spencer S 
Published: October 2015

Abstract
A novel analytical approach involving solvent extraction with methyl tert-butyl ether (MTBE) followed by GC was developed to quantify residues that result from the postharvest fumigation of almonds and walnuts with propylene oxide (PPO). Verification and quantification of PPO, propylene chlorohydrin (PCH) [1-chloropropan-2-ol (PCH-1) and 2-chloropropan-1-ol (PCH-2)], and propylene bromohydrin (PBH) [1-bromopropan-2-ol (PBH-1) and 2-bromopropan-1-ol (PBH-2)] was accomplished with a combination of electron impact ionization MS (EIMS), negative ion chemical ionization MS (NCIMS), and electron capture detection (ECD). Respective GC/EIMS LOQs for PPO, PCH-1, PCH-2, PBH-1, and PBH-2 in MTBE extracts were [ppm (μg/g nut)] 0.9, 2.1, 2.5, 30.3, and 50.0 for almonds and 0.8, 2.2, 2.02, 41.6, and 45.7 for walnuts. Relative to GC/EIMS, GC-ECD analyses resulted in no detection of PPO, similar detector responses for PCH isomers, and &gt;100-fold more sensitive detection of PBH isomers. NCIMS did not enhance detection of PBH isomers relative to EIMS and was, respectively, approximately 20-, 5-, and 10-fold less sensitive to PPO, PCH-1, and PCH-2. MTBE extraction efficiencies were &gt;90% for all analytes. The 10-fold concentration of MTBE extracts yielded recoveries of 85–105% for the PBH isomers and a concomitant decrease in LODs and LOQs across detector types. The recoveries of PCH isomers and PPO in the MTBE concentrate were relatively low (approximately 50 to 75%), which confound improvements in LODs and LOQs regardless of detector type.