bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental Investigations on the Flow Dynamics and Abandonment Pressure for CO2 Sequestration and Oil Recovery in Artificially Fractured Cores
Authors: Trivedi J.J. , Babadagli T. 
Published: March 2010

Abstract
CO2 flooding in naturally fractured reservoirs is becoming increasingly more popular. The Midale Field is a good example of this phenomenon and has gained a great deal of interest, not only from enhanced oil recovery, but also from a CO2 sequestration point of view. To consider future opportunities for greenhouse sequestration in these types of reservoirs while improving oil recovery specifically in the Midale field, a series of experiments were performed.
The goal of this work was to study the effect of miscibility (miscible, immiscible and near-miscible regions) and injection rate on incremental oil recovery and sequestration during continuous injection in fractured porous media. Another important aspect considered was to analyze the effect of pressure drawdown or depletion on additional recovery with sequestration optimization. First, artificially fractured Berea sandstone samples were used. CO2 was injected at constant, slow rates into the fracture, while maintaining the high-pressure into the core and the system. At the end of the production life, the pressure into the system was released to different pressure steps and kept for a longer period of time at each of the reduced steps of pressure. In between two pressure steps, the system was shut down for enough time to observe the effect of CO2 and oil diffusion/back diffusion. After a series of Berea sandstone experiments, a few tests were conducted on the Midale cores, which were obtained from a good quality matrix part of the field. Injection and production data were collected using a continuous data logging system, an analysis of the produced liquids and measuring the gas production using a continuous flowmeter, which led to the understanding of the mechanism. The results showed that the pressure blowdown, followed by shut in after continuous injection, can increase oil recovery significantly until a certain critical pressure. Storage capacity of the rock with change in pressure and amount of oil recovered during blowdown period will lead to the critical understanding of abandonment pressure during the project life to achieve the goal of sequestration and recovery optimization.
Experimental Study of Solvent Flooding to Heavy Oil in Fractured Five-Spot Micro-Models: The Role of Fracture Geometrical Characteristics
Authors: Farzaneh S.A. , Kharrat R. , Ghazanfari M.H. 
Published: March 2010

Abstract
The solvent-based process appears to be an increasingly feasible technology for the extraction of heavy oil reserves. However, there is a lack of fundamental understanding of how fracture geometrical characteristics control the oil recovery efficiency in this type of enhanced oil recovery (EOR) technique. In this work, a series of experiments were performed whereby the pure and mixed hydrocarbon solvents (HCS) displaced heavy oil in fractured five-spot glass micro-models. Successive images of the solvent injection process were recorded. The oil recovery factor, as a function of injected pore volume of solvents, was measured using image analysis of the provided pictures. It has been observed that the oil recovery decreased when the fractures' spacing, discontinuity, overlap, and distribution increased. In contrast, the oil recovery increased when the orientation angle, discontinuity-distribution and the number of fractures increased. Also, it has been found that there is an optimum solvent composition, which maximizes the oil recovery. Finally, some pore-level visualization representing the role of asphaltene precipitation during miscible injection was illustrated using these experiments. This study demonstrates the applicability of the micro-models for the fundamental studying of the solvent-based process in fractured five-spot systems, which are used to investigate the effect of fracture geometrical characteristics and their effect on oil recovery.
Introduction
Heavy oil and bitumen reserves represent a considerable portion of worldwide energy resources. It is estimated that these reservoirs contain six trillion barrels of oil originally in place (OOIP), which is much more than the total conventional oil reservoirs. Great consumption of light oil reserves and their resulting dramatic decline encourages more interest in exploitation of highly viscous oil and bitumen for future energy demands. For optimum conditions, the primary recovery of these reservoirs would not exceed 10% of the OOIP(1). A variety of thermal methods, including cyclic steam stimulation, in-situ combustion and steam assisted gravity drainage are currently being applied for extraction of these crudes. As far as the reservoir's oil is heated, the main fraction of thermal energy is used up in heating the formation itself. For the reservoirs with a thin pay zone, bottom water zone and/or overlying gas zone, excessive depths, low thermal conductivity of rock matrix, high water saturation, etc., the economical applicability of thermal methods is doubtful. With respect to current available recovery technologies, these reservoirs are categorized as problematic reservoirs(2,3).
Laboratory Studies of Producing Hydrogen and Incremental Oil From Light Oil Reservoirs Using Downhole Gasification
Authors: Greaves M. , Xia T.X. 
Published: March 2010

Abstract
The idea of gasifying (reforming) a fraction of a light crude oil in the reservoir, was conceived originally by Davidson and Yule(1). This involved "stringing?? a series of downhole gasification (DHG) units along either a horizontal producer well or vertical producer well, or along some other suitable well arrangement.
Although catalytic steam reforming of naphtha practiced on a large scale has been extensively researched, such understanding is largely restricted to much lower pressures than those investigated in the present study. We present results obtained using a small, "pilot-scale?? DHG unit, or reforming reactor, operated at up to 100 bar pressure. The feed to this unit was a light naphtha fraction cut from Statfjord crude oil. The effect of pressure, catalyst loading, steam to hydrocarbon ratio and gasifier temperature were investigated.
Essentially, the conversion to inert gases, principally hydrogen and carbon dioxide, at high pressure was sufficiently high to make the process technically feasible in depleted light oil reservoirs. Furthermore, the economics of this novel enhanced oil recovery process, which also produces (and stores) hydrogen, appear to be very favourable. However, the experiments, which were conducted under pilot-scale conditions using a single-tube reactor unit, were not of sufficient duration time to test the long-term effects on catalyst activity owing to carbon fouling and sulphur poisoning. These factors (at least carbon deposition) can be controlled as demonstrated in the experiments by adjusting the steam-to-hydrocarbon ratio and the depth of naphtha-cut taken from the crude oil. These aspects of the process are to be further investigated in a Phase 2 project.
Introduction
Davidson and Yule(1) originally conceived the idea of a self-contained, downhole gasification (DHG) unit as a safer, "greener?? method for transporting oil out of environmentally sensitive areas, such as the Everglades, as gas. Subsequently, the focus was directed towards applying DHG in depleted light oil reservoirs. The inert gases generated by a downhole DHG unit(s) are directed into a gas cap, or used to create a gas cap (Figure 1). This would then allow gravity stabilized displacement (GSGI), WAG, or another assisted gas injection technique, to be implemented for the purpose of improved oil recovery. This is still a high priority, especially in such areas as the North Sea, and the many hundreds of depleted light oil fields in the US, where output continues to fall. The main IOR problem is the availability of a suitable gas to inject into the reservoir, especially offshore. Although the displacement dynamics are likely to be complex because of the hydrogen in the generated gas, it is estimated that valuable incremental oil can be gained using the DHG process.
Efficient Detection of Productive Intervals in Oil and Gas Reservoirs
Authors: Bouffin Nicolas , Jensen Jerry L. 
Published: March 2010

Abstract
The utility and evaluation of cutoff values for net pay or net-to-gross determination have been hotly debated topics since the 1950s. There are numerous subtleties to cutoffs, but exactly how the values are calculated has largely been overlooked. Most cutoff users have been content to use a regression line to calculate the cutoff value.
We show that cutoffs obtained using a regression line are likely to be inferior to estimates produced by other methods. When four methods were applied to two field datasets and compared, regression-based porosity cutoffs were between 1 and 2 pu different than the values that give the smallest number of errors. Monte Carlo simulations broadly support the results obtained from the datasets. One method, the "trial-and-error?? method, performed well through most of the tests, reducing errors by 40% from those obtained using the regression line-based cutoff.
All cutoff estimation methods have errors, caused by the imperfect relationships we have between variables, such as porosity and permeability. This study shows we have a choice of methods. Because the better method can be easily applied in spreadsheet software, this should be a valuable addition to the petrophysicist's toolbox.
Introduction
Net pay (NP) may be defined as any interval containing economically producible hydrocarbon using a specific production method. This represents the portion of the reservoir that contains sufficient porosity, permeability and hydrocarbons for economic exploitation. NP can be interpreted as an effective thickness that is pertinent to identification of flow units and target intervals for well completions and stimulation programs [Worthington and Cosen­tino(1)]. The associated net-to-gross ratio (NGR) corresponds to the proportion of the total or gross thickness, which is composed of net pay.
Numerous papers have reviewed and proposed methods for NP and NGR determination. Snyder(2) covers many of the methods in use up to the early 1970s, which used the self-potential (SP) or gamma ray (GR) logs and core analysis. More recent proposals include using capillary pressure [Vavra et al.(3)], probe permeameter measurements [Flølo et al.(4)] and percolation modelling [Li et al.(5)]. Of the large variety of possible methods, one approach is much more commonly discussed than any other. This method involves defining threshold values (or cutoffs) for the characteristics of interest and their surrogates. These limiting values are designed to define those rock intervals that show potential to contribute significantly to economic hydrocarbon production.
Durability of Oilwell Cement Formulations Aged in H2S-Containing Fluids
Authors: Lécolier E.. , Rivereau A.. , Ferrer N.. , Audibert A.. , Longaygue X.. 
Published: March 2010

Summary
In the next few decades, the production of oil fields with high contents of associated sour gases will increase. For instance, it is estimated that 40% of the world's remaining gas reserves contain more than 2% of carbon dioxide (CO2) and/or more than 100 ppm of hydrogen sulphide (H2S). Therefore, investigations on technologies to produce such fields are of utmost importance. Because of the presence of corrosive gas, special attention has to be paid to the design and the selection of materials (steel and cement) used for well construction. Corrosion of steel caused by acid-gas- containing brines is well documented in the literature, and to a lesser extent, data about the degradation by wet CO2 or wet H2S can be found. For cement-based materials, one can find abundant literature dealing with deterioration of cement pastes because of the CO2 environment. Published data on degradation mechanisms of cement-based materials exposed to H2S environments are more scarce. This paper addresses the problem of durability of oilwell cement in different H2S environments.
Different periods of time can be identified in the lifetime of the wells—the production period (typically between 20 and 40 years), the post-abandonment period (some tens of years following the permanent well abandonment), and the abandonment period (several centuries). For each period of time, cementing materials (primary cementing, plugs) are in contact with different types of fluids. Therefore, to correctly assess the behavior of oilwell cement, aging tests have to be carried out in fluids representative of these different periods of time. In this paper, we present both the methodology implemented under high-pressure/high-temperature conditions for testing materials in H2S-containing fluids and the results obtained on cement-based materials. Main physicochemical degradation mechanisms of cement-based materials caused by H2S are identified using various characterization techniques. Depending on the nature of the fluid in contact with cement materials, severe degradation can occur with a strong impairment of macroscopic properties.
The Value of Layoffs and Labor Market Conditions as Signals of Worker Quality
Authors: Kosovich Stephen M 
Published: March 2010

Abstract
Empirical studies in the job displacement literature have found that workers face significant earnings losses on average when they are permanently displaced from jobs. Previous work also finds that the costliness of job loss varies widely and that some of this variation may result from the differences between layoffs and plant closings. Layoffs provide hiring firms worker specific information about productivity but plant closings do not. This paper extends the understanding of the costs of job loss by presenting a theoretical motivation that indicates that labor market conditions can influence the information contained in a layoff. The empirical results from the Displaced Worker Supplement support this model and suggest that when the local unemployment rate is high, less information is transmitted by a layoff concerning worker quality, for the sample of white-collar workers.
Spectroscopic characterization of halogen- and cyano-substituted pyridinevinylenes synthesized without catalyst or solvent
Authors: Percino M. , Chapela Víctor , Montiel Ling-Fa , Pérez-Gutiérrez Enrique , Maldonado José 
Published: March 2010

AbstractAn efficient Knoevenagel route using green chemistry conditions was applied for the synthesis of halogen- and cyano- substituted pyridinevinylene compounds. Absorption and fluorescence emission spectra of these conjugated compounds were recorded and compared in order to evaluate the effect of substituents on the electronic properties of pyridinevinylene compounds. The substituents studied were terminal Cl and F, two or three aromatic rings, as well as a cyano group attached to a C=C double bond. The compounds synthesized are: (E)-2-(4-fluorostyryl)pyridine, (E)-2-(4-chlorostyryl)pyridine, (E)-4-(4-chlorostyryl)pyridine, 2,3-diphenylacrylonitrile, 3-phenyl-2-(pyridin-2-yl)acrylonitrile, 3-phenyl-2-(pyridin-3-yl)acrylonitrile, 2-phenyl-3-(pyridin-2-yl)acrylonitrile, 3,3′-(1,4-phenylene)bis(2-phenylacrylonitrile), 3,3′-(1,4-phenylene)bis(2-(pyridin-2-yl)acrylonitrile), and 3,3′-(1,4-phenylene)bis(2-(pyridin-3-yl)acrylonitrile). The solvent-free method used in this work allows obtaining each compound by controlling the reaction temperature. The compounds were characterized by infrared spectroscopy and 1H-NMR spectroscopy.
Deposition and release of chlorhexidine from non-ionic and anionic polymer matrices
Authors: Musial Witold , Kokol Vanja , Voncina Bojana 
Published: March 2010

AbstractTherapeutic activity of locally applied drugs depends on both the thermodynamic activity of the active molecule and the pharmaceutical system which enables the release of the molecule; also the vasoconstrictive activity of vessels plays an important role. In this study, the release of chlorhexidine was assessed considering the use of ionic and non-ionic polymeric carriers at temperatures in the range between 22°C and 42°C, including the temperature of 32°C as the reference surface body temperature. The obtained release rates and concentrations of chlorhexidine, loaded to methylcellulose and poly(acrylic acid) gels, were compared with respective viscositiy, pH, and conductivity of the assessed systems. The deposition patterns of chlorhexidine in the polymeric matrix were studied using energy dispersive X-ray spectrometry to evaluate the possible influence of chlorhexidine distribution in/on the carrier on the respective release rates. This study is significant for patients with various skin temperature conditions, who are required to receive local biocides applied on skin or into the oral cavity. The obtained precipitate of polyacrylic acid-chlorhexidine preparation was extensively studied to evaluate the chlorhexidine release and to develop an application in skin and dental care.
The family and the children’s consumption of television: orientations and proposals
Authors: Aguaded-Gómez María de la Cinta 
Published: March 2010

The purpose of this study is to provide a social and educational description of the influence of TV in children’s lives. The sample included children from the 2nd level of Primary Education (third and fourth courses) from «Andévalo School» (Spain). The practical implications of this study for parents are also discussed.
En este trabajo que se expone a continuación se presentan las conclusiones extraídas de una investigación realizada con alumnos de la zona del Andévalo (Provincia de Huelva –España–) que cursan 2º Ciclo de Educación Primaria (Tercero y Cuarto). En este estudio se pretendía averiguar en qué medida la televisión se hace presente en la vida de estos alumnos, y qué repercusiones tiene para su vida escolar y familiar.
Who sees what? Contributions for an open debate about television in the context of media literacy
Authors: Reia-Baptista Vitor 
Published: March 2010

During some of the most recent years, in Portugal there has been a public debate going on about the different roles of television near some of the youngest sectors of the population, either as a priority medium of entertainment, as a privileged medium of information, as a possible medium of learning experiences, or just as a simple (or rather complex) «baby sitter». This debate that seemed to become a promising one, especially at the time of the implementation of a new regulation entity (Regulation Entity for the Social Communication) faded away and did not contribute for any deeper knowledge of the problem. Let us see why.Nos últimos anos, em Portugal, tem-se desenvolvido algum debate público em torno dos diferentes papéis da televisão junto de alguns dos sectores mais jovens da população, seja enquanto meio prioritário de entretenimento, seja enquanto meio privilegiado de informação, seja enquanto possível meio de aprendizagens, ou mesmo enquanto simples (ou bastante complexa) «baby sitter». Este debate, que a seu tempo foi de certo modo promissor pelo facto de se ir estabelecer no panorama televisivo português uma nova entidade reguladora (Entidade Reguladora para a Comunicação Social) acabou por se esvair e não contribuir grandemente para qualquer conhecimento mais aprofundado do problema. Vejamos porquê.
Intelligent audiences: a possible challenge
Authors: Funes Virginia Silvina 
Published: March 2010

Television produces a homogeneization effect which in turn makes everything seem and worth the same. It creates a passive and bored viewer, in short, a consumer. This discourse does not encourage him to be involved in any decoding operation; therefore, it does not embrace him as a subject. However, it would be healthy to think of the teen audience and their relationship with mass culture, not as a lost generation because of their global non-stop consumerism, but rather as young viewers of complex audiovisual texts which also imply the use of complex codes and languages, thus creating a system that makes them active viewers.El discurso televisivo produce un efecto homogeneizador que hace que todo parezca lo mismo y valga lo mismo. Produce, así, un espectador pasivo y aburrido. El discurso no le propone ninguna operación de interpretación que lo implique subjetivamente. Sin embargo, es saludable que pensemos en los adolescentes/televidentes y su relación con sus consumos culturales masivos, no ya como una generación perdida por el consumismo global irremediable, sino como jóvenes espectadores de textos audiovisuales complejos que implican el uso de lenguajes o códigos también complejos, que los interpelan como espectadores/interpretadores activos.
TV and reality: a proposal for teachers´ training
Authors: Martínez-González Alejandro 
Published: March 2010

This paper describes an educational process which enables the participants to a critical analysis of television and its contents. This educational method has been developed at «La Salle» University centre, in a social educators and teachers training course, in the frame of the subject called «Techniques of Social Communication and Advertisement». It is based on a methodology that aims the development and promotion of complex thinking and critical consciousness. Reference to some techniques for the analysis of television in class may also be found.En la presente comunicación se describe el proceso de educación en la capacidad de análisis crítico y cuestionamiento de la televisión y sus contenidos que se viene desarrollando desde el centro universitario «La Salle» en la formación de educadores sociales y maestros dentro de la asignatura titulada «Técnicas de comunicación social y publicidad», a partir de una metodología centrada en la promoción y el desarrollo del pensamiento complejo y la conciencia crítica. Se hace mención, también, de algunas técnicas para el análisis del medio televisivo en el aula.
The consumption of television: a big show
Authors: Rodríguez-Mateos Dolores 
Published: March 2010

The author of this paper defends that the mass media in which she works, stimulates for the show. The influence of television in society has reopened the discussion about educational theories and strategies. Watching TV makes people adopt a passive and alienated posture, without implication or participation. Television channels should be responsible of giving a better service. The author considers all the television media they work should be richer and stimulating for students. The important thing is getting and maintaining the viewer’s attention in the audiovisual context.El nivel instructivo de la TV no puede elevarse si en los espectadores no aumentan la cultura televisiva, que no es otra cosa que «saber leer íntegramente un programa, conociendo y sabiendo valorar los símbolos que se han empleado para contarnos lo que estamos viendo». A la mayoría de las personas que actualmente ven TV, les trae sin cuidado el lenguaje televisivo, no pasan de lo que llamaríamos un primer nivel: el espectáculo. Sólo ven las incidencias y la acción que narra determinado programa. No se comparte ninguna experiencia, lo único que se comparte es el espectáculo, un juego que nadie juega pero que todo el mundo puede contemplar. En la sociedad del espectáculo «lo que aparece es bueno y lo que es bueno aparece». Lo importante es administrar el tiempo libre a través de los medios de comunicación. Debemos dar un paso en la educación audiovisual y afrontar uno de los grandes retos de nuestra era: el estar con la TV. Hay que dejar de ser analfabetos televisivos y convertirnos en personas críticas, activas, creativas e imaginativas... para enriquecer la realidad cultural y social.