1000 resultados para Modelos análogos de reservatório


Relevância:

30.00% 30.00%

Publicador:

Resumo:

The aim of this paper was to evaluate the effect of retention and detention reservoirs along with the regulation in channel flow upgrade on flood for an urban watershed located at Rio Claro, SP. For this purpose, modeling and simulation techniques were applied for runoff determination and its propagation in channel. The Soil Conservation Service – SCS hydrologic model as well as Pulz and non-linear Muskingum-Cunge model were used. The software IPHS1 was applied on simulations. The results pointed out that the combination of retention increasing and detention reservoir implementation (120,000 m3, corresponding to 1.5% of the watershed area) with the streamflow upgrade (n decreasing from 0,04 to 0,02) can minimize the flood on the investigated Servidão watershed. Further, after the proposed intervention, the flood was eliminated for the investigated times of recurrence: 5, 20, 50 and 100 years. The prognostic indicated that the available area occupation had a minor effect on flow increasing due to the observed high urbanization.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Pós-graduação em Física - IFT

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Esta tesis doctoral presenta el desarrollo, verificación y aplicación de un método original de regionalización estadística para generar escenarios locales de clima futuro de temperatura y precipitación diarias, que combina dos pasos. El primer paso es un método de análogos: los "n" días cuya configuración atmosférica de baja resolución es más parecida a la del día problema, se seleccionan de un banco de datos de referencia del pasado. En el segundo paso, se realiza un análisis de regresión múltiple sobre los "n" días más análogos para la temperatura, mientras que para la precipitación se utiliza la distribución de probabilidad de esos "n" días análogos para obtener la estima de precipitación. La verificación de este método se ha llevado a cabo para la España peninsular y las Islas Baleares. Los resultados muestran unas buenas prestaciones para temperatura (BIAS cerca de 0.1ºC y media de errores absolutos alrededor de 1.9ºC); y unas prestaciones aceptables para la precipitación (BIAS razonablemente bajo con una media de -18%; error medio absoluto menor que para una simulación de referencia (la persistencia); y una distribución de probabilidad simulada similar a la observada según dos test no-paramétricos de similitud). Para mostrar la aplicabilidad de la metodología desarrollada, se ha aplicado en detalle en un caso de estudio. El método se aplicó a cuatro modelos climáticos bajo diferentes escenarios futuros de emisiones de gases de efecto invernadero, para la región de Aragón, produciendo así proyecciones futuras de precipitación y temperaturas máximas y mínimas diarias. La fiabilidad de la técnica de regionalización fue evaluada de nuevo para el caso de estudio mediante un proceso de verificación. Para determinar la capacidad de los modelos climáticos para simular el clima real, sus simulaciones del pasado (la denominada salida 20C3M) se regionalizaron y luego se compararon con el clima observado (los resultados son bastante robustos para la temperatura y menos concluyentes para la precipitación). Las proyecciones futuras a escala local presentan un aumento significativo durante todo el siglo XXI de las temperaturas máximas y mínimas para todos los futuros escenarios de emisiones considerados. Las simulaciones de precipitación presentan mayores incertidumbres. Además, la aplicabilidad práctica del método se demostró también mediante su utilización para producir escenarios climáticos futuros para otros casos de estudio en los distintos sectores y regiones del mundo. Se ha prestado especial atención a una aplicación en Centroamérica, una región que ya está sufriendo importantes impactos del cambio climático y que tiene un clima muy diferente. ABSTRACT This doctoral thesis presents the development, verification and application of an original downscaling method for daily temperature and precipitation, which combines two statistical approaches. The first step is an analogue approach: the “n” days most similar to the day to be downscaled are selected. In the second step, a multiple regression analysis using the “n” most analogous days is performed for temperature, whereas for precipitation the probability distribution of the “n” analogous days is used to obtain the amount of precipitation. Verification of this method has been carried out for the Spanish Iberian Peninsula and the Balearic Islands. Results show good performance for temperature (BIAS close to 0.1ºC and Mean Absolute Errors around 1.9ºC); and an acceptable skill for precipitation (reasonably low BIAS with a mean of - 18%, Mean Absolute Error lower than for a reference simulation, i.e. persistence, and a well-simulated probability distribution according to two non-parametric tests of similarity). To show the applicability of the method, a study case has been analyzed. The method was applied to four climate models under different future emission scenarios for the region of Aragón, thus producing future projections of daily precipitation and maximum and minimum temperatures. The reliability of the downscaling technique was re-assessed for the study case by a verification process. To determine the ability of the climate models to simulate the real climate, their simulations of the past (the 20C3M output) were downscaled and then compared with the observed climate – the results are quite robust for temperature and less conclusive for the precipitation. The downscaled future projections exhibit a significant increase during the entire 21st century of the maximum and minimum temperatures for all the considered future emission scenarios. Precipitation simulations exhibit greater uncertainties. Furthermore, the practical applicability of the method was demonstrated also by using it to produce future climate scenarios for some other study cases in different sectors and regions of the world. Special attention was paid to an application of the method in Central America, a region that is already suffering from significant climate change impacts and that has a very different climate from others where the method was previously applied.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Currently a resource more and more used by the petroleum industry to increase the efficiency of steam flood mechanism is the addition of solvents. The process can be understood as a combination of a thermal method (steam injection) with a miscible method (solvent injection), promoting, thus, the reduction of interfacial tensions and oil viscosity. The use of solvent alone tends to be limited because of its high cost. When co-injected with steam, the vaporized solvent condenses in the cooler regions of the reservoir and mixes with the oil, creating a zone of low viscosity between the steam and the heavy oil. The mobility of the displaced fluid is then improved, resulting in an increase of oil recovery. To better understand this improved oil recovery method, a numerical study of the process was done contemplating the effects of some operational parameters (distance between wells, injection steam rate, kind of solvent and injected solvent volume)on the accumulated production of oil, recovery factor and oil-steam rate. Semisynthetic models were used in this study but reservoir data can be extrapolated for practical applications situations on Potiguar Basin. Simulations were performed in STARS (CMG, 2007.11). It was found that injected solvent volumes increased oil recovery and oil rates. Further the majority of the injected solvent was produced and can be recycled

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In the present study we elaborated algorithms by using concepts from percolation theory which analyze the connectivity conditions in geological models of petroleum reservoirs. From the petrophysical parameters such as permeability, porosity, transmittivity and others, which may be generated by any statistical process, it is possible to determine the portion of the model with more connected cells, what the interconnected wells are, and the critical path between injector and source wells. This allows to classify the reservoir according to the modeled petrophysical parameters. This also make it possible to determine the percentage of the reservoir to which each well is connected. Generally, the connected regions and the respective minima and/or maxima in the occurrence of the petrophysical parameters studied constitute a good manner to characterize a reservoir volumetrically. Therefore, the algorithms allow to optimize the positioning of wells, offering a preview of the general conditions of the given model s connectivity. The intent is not to evaluate geological models, but to show how to interpret the deposits, how their petrophysical characteristics are spatially distributed, and how the connections between the several parts of the system are resolved, showing their critical paths and backbones. The execution of these algorithms allows us to know the properties of the model s connectivity before the work on reservoir flux simulation is started

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Water injection is the most widely used method for supplementary recovery in many oil fields due to various reasons, like the fact that water is an effective displacing agent of low viscosity oils, the water injection projects are relatively simple to establish and the water availability at a relatively low cost. For design of water injection projects is necessary to do reservoir studies in order to define the various parameters needed to increase the effectiveness of the method. For this kind of study can be used several mathematical models classified into two general categories: analytical or numerical. The present work aims to do a comparative analysis between the results presented by flow lines simulator and conventional finite differences simulator; both types of simulators are based on numerical methods designed to model light oil reservoirs subjected to water injection. Therefore, it was defined two reservoir models: the first one was a heterogeneous model whose petrophysical properties vary along the reservoir and the other one was created using average petrophysical properties obtained from the first model. Comparisons were done considering that the results of these two models were always in the same operational conditions. Then some rock and fluid parameters have been changed in both models and again the results were compared. From the factorial design, that was done to study the sensitivity analysis of reservoir parameters, a few cases were chosen to study the role of water injection rate and the vertical position of wells perforations in production forecast. It was observed that the results from the two simulators are quite similar in most of the cases; differences were found only in those cases where there was an increase in gas solubility ratio of the model. Thus, it was concluded that in flow simulation of reservoirs analogous of those now studied, mainly when the gas solubility ratio is low, the conventional finite differences simulator may be replaced by flow lines simulator the production forecast is compatible but the computational processing time is lower.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The objective of the thermal recovery is to heat the resevoir and the oil in it to increase its recovery. In the Potiguar river basin there are located several heavy oil reservoirs whose primary recovery energy provides us with a little oil flow, which makes these reservoirs great candidates for application of a method of recovery advanced of the oil, especially the thermal. The steam injection can occur on a cyclical or continuous manner. The continuous steam injection occurs through injection wells, which in its vicinity form a zone of steam that expands itself, having as a consequence the displace of the oil with viscosity and mobility improved towards the producing wells. Another possible mechanism of displacement of oil in reservoirs subjected to continuous injection of steam is the distillation of oil by steam, which at high temperatures; their lighter fractions can be vaporized by changing the composition of the oil produced, of the oil residual or to shatter in the amount of oil produced. In this context, this paper aims to study the influence of compositional models in the continuous injection of steam through in the analysis of some parameters such as flow injection steam and temperature of injection. Were made various leading comparative analysis taking the various models of fluid, varying from a good elementary, with 03 pseudocomponents to a modeling of fluids with increasing numbers of pseudocomponents. A commercial numerical simulator was used for the study from a homogeneous reservoir model with similar features to those found in northeastern Brazil. Some conclusions as the increasing of the simulation time with increasing number of pseudocomponents, the significant influence of flow injection on cumulative production of oil and little influence of the number of pseudocomponents in the flows and cumulative production of oil were found

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Face à Directiva 2007/60/CE relativa à avaliação e gestão do risco de inundações, ao Decreto-Lei nº 344/2007 que aprova o Regulamento de Segurança de Barragens, ao aumento de áreas urbanizadas e às projecções dos modelos de clima para o fim do século, que apontam para o aumento da frequência e da intensidade da ocorrência de inundações causadas por eventos de precipitação intensa de curta duração, é crucial a definição de regras de operação nos reservatórios com controlo de cheias. O Reservatório de Magos pertence à bacia hidrográfica do rio Tejo, está situado no Concelho de Salvaterra de Magos e tem como usos principais a rega e o controlo de cheias. Este trabalho tem como objecto de estudo a definição das regras de operação (restrição no caudal descarregado) do Reservatório de Magos para controlo de cheias no troço a jusante. São aplicados o modelo hidrológico HEC-HMS 3.1.0, o modelo hidráulico HEC-RAS 3.1.3 e o modelo de simulação de reservatórios HEC-ResSim 3.O para o cálculo do hidrograma de cheia, da zona inundável e para simulação do balanço de água no reservatório, respectivamente. Como resultado são apresentadas as regras de operação (caudal máximo e mínimo a descarregar) do Reservatório de Magos para controlo da zona inundável a jusante, no caso de um evento de cheia. /ABSTRACT: Based on the Directive 2007/60/CE related to the Assessment and Management of Flood Risks, on the Decree-Law n. o 344/2007 which approves the Regulation for Dam Safety, the increased urban areas and to the projections of climate models by the end of the century which is pointing to an increased frequency and intensity of occurrence of floods caused by intense rainfall events of short duration, establishing rules of operation for flood control in reservoirs becomes crucial. The Magos Reservoir belongs to the river Tagus basin, located in the county of Salvaterra de Magos and has as its main uses the irrigation and flood control. This study aims to establish the rules of operation (flow discharged restriction) of the Reservoir of Magos for flood control in the downstream reach. The methodology used in the present work includes the application of the Hydrological model HEC-HMS 3.1.0, the Hydraulic model HEC-RAS 3.1.3 and a reservoir simulation model HEC-ResSim 3.0 to calculate the hydrograph of peak discharge, floodplain zone and simulate reservoir operations, respectively. As a result, the rules of operation (maximum flow and minimum discharge) of Magos Reservoir for flood control in a downstream reach in case of flood event are presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Restorative proctocolectomy is the procedure of choice to treat familial adenomatous polyposis, however it can be associated to short-term and long-term postoperative complications. AIM: To evaluate the occurrence of complications related to the surgical treatment of familial adenomatous polyposis with ileal pouch technique. METHODS: Retrospective study of 69 patients with familial adenomatous polyposis after rectocolectomy with ileal reservoir between 1984 and 2006, operated on Coloproctology Group, Medical Sciences Faculty, State University of Campinas, Campinas, SP, Brazil. The median follow-up period was 82 (2-280) months. Data obtained were surgical techniques and postoperative complications. RESULTS: The morbidity and mortality were 63.8% and 2.9%, respectively. The most frequent complications were small-bowel obstruction (17.4%), anastomotic stricture (15.9%) and pelvic sepsis (10.1%). Acute ischemia of the ileal pouch (4.3%), pouchitis (2.9%) and ileal pouch-related fistula (2.9%) had poorer frequency than others. CONCLUSIONS: The morbid-mortality was similar to the literature?s data and it is acceptable for a complex surgery in two terms like the ileal reservoir-anal anastomosis. The small-bowel obstruction was the most frequent complication. However, ischemia of the reservoir, pouchitis and pelvic sepsis were important complications and was related to the failure of the ileal reservoir.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work outlines the historic development of the concept and main theories of energy transfer, as well as the principal experiments carried out to confirm or refute the proposed theories. Energy transfer in coordination compounds is also discussed with a focus on rare earth systems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The research approaches recycling of urban waste compost (UWC) as an alternative fertilizer for sugarcane crop and as a social and environmental solution to the solids residuals growth in urban centers. A mathematical model was used in order to know the metal dynamics as decision support tool, aiming to establish of criteria and procedures for UWC's safe use, limited by the amount of heavy metal. A compartmental model was developed from experimental data in controlled conditions and partially checked with field data. This model described the heavy metal transference in the system soil-root-aerial portion of sugarcane plants and concluded that nickel was metal to be concern, since it takes approximately three years to be attenuated in the soil, reaching the aerial portions of the plant at high concentrations. Regarding factors such as clay content, oxide level and soil pH, it was observed that for soil with higher buffering capacity, the transfer of the majority of the metals was slower. This model may become an important tool for the attainment of laws regarding the UWC use, aiming to reduce environment contamination the waste accumulation and production costs.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The study of female broiler breeders is of great importance for the country as poultry production is one of the largest export items, and Brazil is the second largest broiler meat exporter. Animal behavior is known as a response to the effect of several interaction factors among them the environment. In this way the internal housing environment is an element that gives hints regarding to the bird s thermal comfort. Female broiler breeder behavior, expresses in form of specific pattern the bird s health and welfare. This research had the objective of applying predictive statistical models through the use of simulation, presenting animal comfort scenarios facing distinct environmental conditions. The research was developed with data collected in a controlled environment using Hybro - PG® breeding submitted to distinct levels of temperature, three distinct types of standard ration and age. Descriptive and exploratory analysis were proceeded, and afterwards the modeling process using the Generalized Estimation Equation (GEE). The research allowed the development of the thermal comfort indicators by statistical model equations of predicting female broiler breeder behavior under distinct studied scenarios.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The main objective of this work was to evaluate the linear regression between spectral response and soybean yield in regional scale. In this study were monitored 36 municipalities from the west region of the states of Parana using five images of Landsat 5/TM during 2004/05 season. The spectral response was converted in physical values, apparent and surface reflectances, by radiometric transformation and atmospheric corrections and both used to calculate NDVI and GVI vegetation indices. Those ones were compared by multiple and simple regression with government official yield values (IBGE). Diagnostic processing method to identify influents values or collinearity was applied to the data too. The results showed that the mean surface reflectance value from all images was more correlated with yield than individual dates. Further, the multiple regressions using all dates and both vegetation indices gave better results than simple regression.