Análise paramétrica da simulação composicional do processo de Drenagem Gravitacional Assistida por Gás (GAGD)

In Brazil and around the world, oil companies are looking for, and expected development of new technologies and processes that can increase the oil recovery factor in mature reservoirs, in a simple and inexpensive way. So, the latest research has developed a new process called Gas Assisted Gravity Drainage (GAGD) which was classified as a gas injection IOR. The process, which is undergoing pilot testing in the field, is being extensively studied through physical scale models and core-floods laboratory, due to high oil recoveries in relation to other gas injection IOR. This process consists of injecting gas at the top of a reservoir through horizontal or vertical injector wells and displacing the oil, taking advantage of natural gravity segregation of fluids, to a horizontal producer well placed at the bottom of the reservoir. To study this process it was modeled a homogeneous reservoir and a model of multi-component fluid with characteristics similar to light oil Brazilian fields through a compositional simulator, to optimize the operational parameters. The model of the process was simulated in GEM (CMG, 2009.10). The operational parameters studied were the gas injection rate, the type of gas injection, the location of the injector and production well. We also studied the presence of water drive in the process. The results showed that the maximum vertical spacing between the two wells, caused the maximum recovery of oil in GAGD. Also, it was found that the largest flow injection, it obtained the largest recovery factors. This parameter controls the speed of the front of the gas injected and determined if the gravitational force dominates or not the process in the recovery of oil. Natural gas had better performance than CO2 and that the presence of aquifer in the reservoir was less influential in the process. In economic analysis found that by injecting natural gas is obtained more economically beneficial than CO2

Modelagem e simulação de um sistema de bombeio mecânico em poços direcionais utilizando parâmetros concentrados

This work aims presenting the development of a model and computer simulation of a sucker rod pumping system. This system take into account the well geometry, the flow through the tubing, the dynamic behavior of the rod string and the use of a induction motor model. The rod string were modeled using concentrated parameters, allowing the use of ordinary differential equations systems to simulate it s behavior

Simulação computacional como ferramenta de auxílio ao projeto: aplicação em edifícios naturalmente ventilados no clima de Natal/RN

Natural air ventilation is the most import passive strategy to provide thermal comfort in hot and humid climates and a significant low energy strategy. However, the natural ventilated building requires more attention with the architectural design than a conventional building with air conditioning systems, and the results are less reliable. Therefore, this thesis focuses on softwares and methods to predict the natural ventilation performance from the point of view of the architect, with limited resource and knowledge of fluid mechanics. A typical prefabricated building was modelled due to its simplified geometry, low cost and occurrence at the local campus. Firstly, the study emphasized the use of computational fluid dynamics (CFD) software, to simulate the air flow outside and inside the building. A series of approaches were developed to make the simulations possible, compromising the results fidelity. Secondly, the results of CFD simulations were used as the input of an energy tool, to simulate the thermal performance under different rates of air renew. Thirdly, the results of temperature were assessed in terms of thermal comfort. Complementary simulations were carried out to detail the analyses. The results show the potentialities of these tools. However the discussions concerning the simplifications of the approaches, the limitations of the tools and the level of knowledge of the average architect are the major contribution of this study

Produção animal no Brasil: caracterização, simulação de cenários para pastagens e alternativas de adaptação às mudanças climáticas.

2015

Simulação do escoamento monofásico em um estágio de uma bomba centrífuga utilizando técnicas de fluidodinâmica computacional

Oil production and exploration techniques have evolved in the last decades in order to increase fluid flows and optimize how the required equipment are used. The base functioning of Electric Submersible Pumping (ESP) lift method is the use of an electric downhole motor to move a centrifugal pump and transport the fluids to the surface. The Electric Submersible Pumping is an option that has been gaining ground among the methods of Artificial Lift due to the ability to handle a large flow of liquid in onshore and offshore environments. The performance of a well equipped with ESP systems is intrinsically related to the centrifugal pump operation. It is the pump that has the function to turn the motor power into Head. In this present work, a computer model to analyze the three-dimensional flow in a centrifugal pump used in Electric Submersible Pumping has been developed. Through the commercial program, ANSYS® CFX®, initially using water as fluid flow, the geometry and simulation parameters have been defined in order to obtain an approximation of what occurs inside the channels of the impeller and diffuser pump in terms of flow. Three different geometry conditions were initially tested to determine which is most suitable to solving the problem. After choosing the most appropriate geometry, three mesh conditions were analyzed and the obtained values were compared to the experimental characteristic curve of Head provided by the manufacturer. The results have approached the experimental curve, the simulation time and the model convergence were satisfactory if it is considered that the studied problem involves numerical analysis. After the tests with water, oil was used in the simulations. The results were compared to a methodology used in the petroleum industry to correct viscosity. In general, for models with water and oil, the results with single-phase fluids were coherent with the experimental curves and, through three-dimensional computer models, they are a preliminary evaluation for the analysis of the two-phase flow inside the channels of centrifugal pump used in ESP systems

Simulação de fluxo de fluidos em meios porosos desordenados uma análise de efeito de escala na estimativa da permeabilidade e do coeficiente de arrasto

The present study provides a methodology that gives a predictive character the computer simulations based on detailed models of the geometry of a porous medium. We using the software FLUENT to investigate the flow of a viscous Newtonian fluid through a random fractal medium which simplifies a two-dimensional disordered porous medium representing a petroleum reservoir. This fractal model is formed by obstacles of various sizes, whose size distribution function follows a power law where exponent is defined as the fractal dimension of fractionation Dff of the model characterizing the process of fragmentation these obstacles. They are randomly disposed in a rectangular channel. The modeling process incorporates modern concepts, scaling laws, to analyze the influence of heterogeneity found in the fields of the porosity and of the permeability in such a way as to characterize the medium in terms of their fractal properties. This procedure allows numerically analyze the measurements of permeability k and the drag coefficient Cd proposed relationships, like power law, for these properties on various modeling schemes. The purpose of this research is to study the variability provided by these heterogeneities where the velocity field and other details of viscous fluid dynamics are obtained by solving numerically the continuity and Navier-Stokes equations at pore level and observe how the fractal dimension of fractionation of the model can affect their hydrodynamic properties. This study were considered two classes of models, models with constant porosity, MPC, and models with varying porosity, MPV. The results have allowed us to find numerical relationship between the permeability, drag coefficient and the fractal dimension of fractionation of the medium. Based on these numerical results we have proposed scaling relations and algebraic expressions involving the relevant parameters of the phenomenon. In this study analytical equations were determined for Dff depending on the geometrical parameters of the models. We also found a relation between the permeability and the drag coefficient which is inversely proportional to one another. As for the difference in behavior it is most striking in the classes of models MPV. That is, the fact that the porosity vary in these models is an additional factor that plays a significant role in flow analysis. Finally, the results proved satisfactory and consistent, which demonstrates the effectiveness of the referred methodology for all applications analyzed in this study.

Avaliação do petróleo por termogravimetria para simulação de curva PEV, fator de caracterização e resíduo de carbono

Petroleum evaluation is analyze it using different methodologies, following international standards to know their chemical and physicochemical properties, contaminant levels, composition and especially their ability to generate derivatives. Many of these analyzes consuming a lot of time, large amount of samples , supplies and need an organized transportation logistics, schedule and professionals involved. Looking for alternatives that optimize the evaluation and enable the use of new technologies, seven samples of different centrifuged Brazilian oils previously characterized by Petrobras were analyzed by thermogravimetry in 25-900° C range using heating rates of 05, 10 and 20ºC per minute. With experimental data obtained, characterizations correlations were performed and provided: generation of true boiling point curves (TBP) simulated; comparing fractions generated with appropriate cut standard in temperature ranges; an approach to obtain Watson characterization factor; and compare micro carbon residue formed. The results showed a good chance of reproducing simulated TBP curve from thermogravimetry taking into account the composition, density and other oil properties. Proposed correlations for experimental characterization factor and carbon residue followed Petrobras characterizations, showing that thermogravimetry can be used as a tool on oil evaluation, because your quick analysis, accuracy, and requires a minimum number of samples and consumables

Percusión corporal, estimulación cognitiva y socioemocional a través del método BAPNE

El método Bapne es un método de estimulación cognitiva que integra música y movimiento a través de la Percusión corporal. El trabajo socioemocional en el método BAPNE viene trabajado en una de sus líneas en la gestión de grupos, liderazgo y mediación a través del Team Building, con la finalidad de explorar todo su potencial como herramienta en la construcción de equipos. El team building es una filosofía del diseño del trabajo, que desde hace más de dos décadas, plantea que para conseguir un mayor rendimiento y eficacia organizacional es más útil percibir a los empleados como miembros interdependientes de equipos, que como trabajadores individuales. A través de la dimensión social, corporal y afectiva el método Bapne es capaz de desarrollar una visión compartida y un propósito único, estimular una identidad de equipo y una atmósfera de confianza y finalmente mejorar los niveles de comunicación y satisfacción individuales en las tareas grupales. Nuestro lema en BAPNE es: tu actitud, no tu aptitud, es la que determinará tu altitud.

Ferramentas interativas na reabilitação cognitiva pós-AVC: RehabCity

O acidente vascular cerebral (AVC) é uma das doenças com mais mortalidade e morbilidade em todo o mundo, provocando danos neurológicos, que podem influenciar a capacidade motora e cognitiva, tendo grandes repercussões na qualidade de vida do individuo bem como para os seus familiares e cuidadores. É importante não descurar da reabilitação cognitiva, pois esta é tão importante quanto a reabilitação motora. A reabilitação irá potenciar toda e qualquer oportunidade de recuperar a sua independência quer a nível social quer nas suas atividades de vida diária (AVD), ou seja tem por objetivo recuperar ou estimular as capacidades funcionais do indivíduo. Este estudo tem por objetivo avaliar a eficácia da realidade virtual (RV) na reabilitação cognitiva de vítimas de AVC. Neste sentido e recorrendo às potencialidades da RV, criou-se um ambiente virtual ecologicamente válido, que simula AVD´s: a RehabCity. Para avaliar a eficácia deste ambiente virtual efetuou-se uma avaliação neuropsicológica pré e pós-intervenção recorrendo a instrumentos que permitem uma avaliação da capacidade cognitiva. Recorreu-se a uma amostra de dezoito participantes, dividida em dois grupos, o grupo experimental e o grupo de controlo, sendo o grupo de experimental alvo de uma intervenção com a RV enquanto o grupo de controlo com uma intervenção tradicional. Os resultados obtidos na avaliação cognitiva entre a pré e pós-intervenção permite-nos afirmar que de facto a RehabCity teve um impacto positivo no grupo experimental, pois observou-se ganhos significativos ao contrário do grupo de controlo que não apresentou melhorias significativas entre a pré e pós-intervenção. Estes resultados, confirma-se que os ambientes virtuais têm um impacto no processo de reabilitação cognitiva. Neste sentido, é importante se instaurar novos métodos de reabilitação cognitiva nos centros de reabilitação, de modo a potencializar e recuperar as funções cognitivas afetadas e consequentemente melhorar a qualidade de vida dos indivíduos vítimas de AVC.

O Impacto de um Programa de Estimulação Cognitiva em Pessoas Idosas a Residir na Comunidade vs. Institucionalizadas

Este estudo procura examinar os benefícios de um programa de estimulação cognitiva na redução do isolamento, comportamentos de afastamento e irritabilidade e na melhoria da capacidade cognitiva e estado emocional. O programa constituído por 14 sessões foi aplicado num grupo de pessoas a residir na comunidade (n=6) e num grupo de idosos a viver em estrutura residencial (n=6). Ambos os grupos foram avaliados antes e após a intervenção com recurso ao instrumento Multidimensional Observation Scale for Elderly Subjects (MOSES). Complementarmente, foi desenvolvido um focus-group com os dinamizadores do programa, que incluiu questões acerca das suas experiências e opiniões sobre as sessões. Resultados estatisticamente significativos apontam para benefícios nos domínios das relações interpessoais e estado emocional, ambos no grupo que recebeu a intervenção no domicílio. Assim, a implementação de programas de estimulação cognitiva deve ser alargada a serviços de apoio domiciliário e projetos mais direcionados para as pessoas que vivem sozinhas.

O Impacto de um Programa de Estimulação Cognitiva em Pessoas Idosas a Residir na Comunidade vs. Institucionalizadas

This study aims to examine the benefits of a cognitive stimulation program in reducing social isolation and irritability and improving cognitive capacity and emotional status of elderly people. A program of 14 sessions was conducted with individuals living in the community (n=6) and with group of individuals living in nursing home (n=6). Both groups were evaluated before and after the intervention with the Multidimensional Observation Scale for Elderly Subjects (MOSES). Also a focus group with the program monitors ́ allowed to collect information about the experience in conducting the sessions and their opinion about the whole program. Results have demonstrated benefits statistically significant in the domains of relationships and emotional status for the group who received the intervention at home. This experience allowed to conclude that the implementation of cognitive stimulation programs should be extended to home-based services, especially for older persons living alone.

Ferramentas interativas na reabilitação cognitiva pós-AVC: RehabCity

O acidente vascular cerebral (AVC) é uma das doenças com mais mortalidade e morbilidade em todo o mundo, provocando danos neurológicos, que podem influenciar a capacidade motora e cognitiva, tendo grandes repercussões na qualidade de vida do individuo bem como para os seus familiares e cuidadores. É importante não descurar da reabilitação cognitiva, pois esta é tão importante quanto a reabilitação motora. A reabilitação irá potenciar toda e qualquer oportunidade de recuperar a sua independência quer a nível social quer nas suas atividades de vida diária (AVD), ou seja tem por objetivo recuperar ou estimular as capacidades funcionais do indivíduo. Este estudo tem por objetivo avaliar a eficácia da realidade virtual (RV) na reabilitação cognitiva de vítimas de AVC. Neste sentido e recorrendo às potencialidades da RV, criou-se um ambiente virtual ecologicamente válido, que simula AVD´s: a RehabCity. Para avaliar a eficácia deste ambiente virtual efetuou-se uma avaliação neuropsicológica pré e pós-intervenção recorrendo a instrumentos que permitem uma avaliação da capacidade cognitiva. Recorreu-se a uma amostra de dezoito participantes, dividida em dois grupos, o grupo experimental e o grupo de controlo, sendo o grupo de experimental alvo de uma intervenção com a RV enquanto o grupo de controlo com uma intervenção tradicional. Os resultados obtidos na avaliação cognitiva entre a pré e pós-intervenção permite-nos afirmar que de facto a RehabCity teve um impacto positivo no grupo experimental, pois observou-se ganhos significativos ao contrário do grupo de controlo que não apresentou melhorias significativas entre a pré e pós-intervenção. Estes resultados, confirma-se que os ambientes virtuais têm um impacto no processo de reabilitação cognitiva. Neste sentido, é importante se instaurar novos métodos de reabilitação cognitiva nos centros de reabilitação, de modo a potencializar e recuperar as funções cognitivas afetadas e consequentemente melhorar a qualidade de vida dos indivíduos vítimas de AVC.

Caracterización de la función cognitiva de niños con síndrome de down de 5 a 12 años en la ciudad de Bogotá

Los niños que padecen trisomía 21 poseen una serie de características físicas, neurológicas y neuropsicológicas específicas, las cuales han sido investigadas a profundidad en diferentes países, de lo cual se han desarrollado protocolos de evaluación para estos niños acorde a su nacionalidad (García, 2010). A pesar de que Colombia es uno de los países en los cuales el síndrome de Down se presenta con mayor frecuencia, hasta la fecha, no se encuentran estudios que enfaticen en las habilidades neuropsicológicas de esta población específica, por lo cual no se han desarrollado protocolos de evaluación adecuados para los niños con síndrome este síndrome. Esta investigación se llevó acabo con una población de 88 niños a los cuales se les aplicó el inventario de desarrollo BATTELLE, y se identificó que los niños con síndrome Down de 5 a 12 años obtienen un puntaje que se encuentra en 4 desviaciones estándar por debajo de la media típica. Lo anterior demuestra una característica específica de esta población en cuanto a patrones de desarrollo en las cuales, se evidencia dificultad más importante en las área cognición y de la comunicación expresiva. Con respecto a los intervalos de edad se identificó que a lo largo de estos el desempeño en las áreas evaluadas decrece. esto puede estar relacionado con la mayor complejidad de los hitos del desarrollo para una edad esperada. Debido a que los hitos del desarrollo esperados varían a lo largo de los periodos del ciclo vital del ser humano, estos tienden a aumentar su complejidad en etapas del desarrollo más avanzados; como estos niños poseen una serie de dificultades en las funciones ejecutivas y cognición, no lograrán alcanzar dichos hitos del desarrollo.