Predicting well inflow performance relationship accurately is very important for production engineers. From these predictions, future plans for handling and improving well performance can be established. One method of predicting well inflow performance is to use artificial neural networks. Vogel's reference curve, which is produced from a series of simulation runs for a reservoir model proposed by Weller, is typically used to predict inflow performance relationship for solution-gas-drive reservoirs. In this study, I reproduced Vogel's work, but instead of producing one curve by conventional regression, I built three neural network models. Two models predict the IPR efficiently with higher overall accuracy than Vogel's reference curve.

In this work we propose two new Vogel-type Inflow Performance Relations (or IPR) correlations for gas-condensate reservoir systems. One correlation predicts dry gas production the other predicts condensate (liquid) production. These correlations provide a linkage between reservoir rock and fluid properties (dewpoint, temperature, and endpoint relative permeabilities, composition, etc.) to the flowrate-pressure performance for the reservoir system. The proposed IPR relationships for compositional reservoir systems are based on data from over 3000 compositional reservoir simulation cases developed using various fluid properties and relative perme-ability curves. The resulting IPR curves for gas condensate systems are quadratic in behavior - similar to the Vogel IPR trends (the Vogel (quadratic) rate-pressure profile is generally presumed for the case of a solution gas-drive reservoir system). However, in the case of a gas-condensate reservoir system, the coefficients in the quadratic relationship vary significantly depending on the richness of the gas conden-sate fluid (i.e., the composition) as well as the relative permeability-saturation behavior. Using an alter-nating conditional expectation approach (i.e., non-parametric regression), an approximate model was de-veloped to estimate these coefficients. This work also includes a discussion of the Vogel IPR for solution gas-drive systems. The original work proposed by Vogel is based on an empirical correlation of numerical simulations for a solution-gas-drive system. Our work provides a critical validation and extension of the Vogel work by establishing a simple, yet rigorous formulation for flowrate-pressure performance in terms of effective permeabilities and pres-sure-dependent fluid properties. The direct application of this work is to predict the IPR for a given reservoir system directly from rock-fluid properties and fluid properties. This formulation provides a new mechanism that can be used to couple the flowrate and pressure behavior for solution gas-drive systems and we believe that it may be possible to extend the proposed semi-analytical concept to gas-condensate reservoir systems. However, for this work we have only considered a semi-empirical IPR approach (i.e., a data-derived correlation) for the case of gas-condensate reservoir systems. We recognize that further work should be performed in this area, and we encourage future research on the topic of semi-analytical modeling of IPR behavior for gas-condensate reservoir systems.

Planktonic algae are useful as indicators of water quality because their composition and distribution reflects environmental condition in lakes. Therefore, understanding their dynamics can aid certain water quality management goals. Lake Diefenbaker is a large mesotrophic reservoir in the Canadian Prairies. Approximately 98 % of its inflow is from the South Saskatchewan River. The composition and ecology of the phytoplankton community has not been reported comprehensively since the 1980s. This is a potential problem for a reservoir with multiple end users. Therefore, I collected epilimnetic whole water samples along its length from June to October in 2011 and in 2012. I examined the phytoplankton community and related their distribution to environmental factors. A total of 72 phytoplankton genera were observed with the chlorophytes having the highest number of genera (33). The increased nutrient load and non-algal turbidity associated with high inflow from the South Saskatchewan River may be related to the dominance of the cryptophytes and bacillariophytes (together constituting ~89 % of the total phytoplankton biomass). The cryptophytes were abundant during periods of high flow rates and thermal stratification whereas the bacillariophytes were abundant during cool, isothermal conditions. Lake Diefenbaker is characterized by numerous embayments. Some of these embayments are exposed to human activities including development (housing, golf courses, marinas) and livestock operations (e.g., cattle watering). These localized activities could increase the frequency or size of algal blooms that will adversely affect the water quality. Therefore, I compared the phytoplankton community composition from eight exposed embayments, four unexposed embayments and six main channel sites. Phytoplankton community compositions were not significantly different in exposed, unexposed embayments and main channel sites (P > 0.05). High flows may have overridden localized influence from embayments. Hence, similar environmental conditions were present in the embayments and main channel. Blooms of cyanobacteria are of concern because of the potential of some genera to produce cyanotoxins. I examined cyanobacteria in Lake Diefenbaker. Cyanobacterial biomass was low in Lake Diefenbaker (< 5 %). However, I observed some potential toxin and bloom-forming genera that may threaten the water quality under different environmental conditions in the future.

No description available.

The aim of this thesis is to study the effects of turbulent flow on a fixed pitch tidal current turbine from the perspective of turbine design and operation. A prototype turbine, Deltastream as it is known, is being developed by Tidal Energy Ltd for deployment in Ramsey Sound, Wales. It is well known that turbulence plays an important role in the fatigue life of marine turbines. Field measurements of tidal flow at the turbine site were analysed to establish the velocity spectra and turbulence intensity. This revealed a wide range of anisotropic turbulence which is dependent upon the tidal direction with intensities ranging from 5-20%. A numerical turbine model based on momentum theory was constructed in a time marching formulation that accounts for the effects of dynamic inflow and rotationally augmented airfoil stall delay properties. The turbine rotor design allows for load alleviation by regulation of the turbine tip speed ratio. At flow velocities above the rated velocity the tip speed ratio can be increased to reduce turbine loads. The model has been combined with a novel rotor speed control algorithm that estimates unsteady turbine inflow velocity from turbine loading without the requirement for external sensing of flow speed. When the turbine is subjected to three dimensional turbulent inflow the rotor speed controller has been shown to significantly reduce the fatigue effect of unsteady, turbulent flow. The turbine blade design has been developed using the model established. Experimental validation studies were carried out at 1/16th scale in turbulent conditions. Studies using the model have; identified the relationship between turbulence intensity and turbine fatigue load, established a controller schedule to significantly reduce fatigue loading and determined the blading fatigue life in realistic turbulent flows.

In this study the dynamic induced velocity field of a model helicopter rotor - excited in collective and cyclic pitch at frequencies extending to 1.5 times the nominal shaft speed - is investigated using mainly hot-wire and laser Doppler anemometry. The dynamic induced velocities are found to vary significantly with radial station and frequency. For cyclic excitations, azimuthal variations are also observed. The results point to the dynamic induced flow being influenced by the distribution of shed vorticity in the wake and cannot be explained using simple momentum theory. Vertical variations of the measured inflow response are also observed, with phase changes possibly partly due to transmission type delays. At frequencies above shaft speed a change in character of the induced flow is seen and around shaft speed an increase in the general level of turbulence is found. The available data on the dynamic induced velocity field of a rotor under controlled excitation, are substantially extended. The measured induced flow response was compared to that predicted using the Pitt and Peters dynamic inflow model. In the 'collective' case good agreement was found, suggesting that the primary inflow model parameters such as the inflow gain and apparent mass are correct with some evidence that a higher order inflow representation might be desirable. A novel method is used to infer the aerodynamic hub loading, which could not be directly measured, from the blade flapping data. This is used to isolate the inflow response using the Pitt and Peters dynamic inflow model and the results are compared with experimental measurements. The method shows the Pitt and Peters dynamic inflow representation to be adequate in the 'collective' case. In the 'cyclic' case, the inferred hub loads were very sensitive to the blade model and hence conclusions for this case are limited. A literature survey and review of the Pitt and Peters dynamic inflow model are also given

A técnica de \"Inflow Occlusion\" pode ser utilizada em cirurgias cardíacas quando se pretende manter o coração aberto apenas por alguns minutos, para realização de pequenos reparos. No entanto, a parada circulatória total, evento decorrente da técnica em questão, pode acarretar severas alterações metabólicas e neurológicas, sendo necessária monitorização trans e pósoperatória do paciente. Neste estudo foram utilizados 12 cães sem raça definida, os quais foram divididos em dois grupos, A e B, submetidos a 7 e 8 minutos de parada circulatória total, respectivamente, utilizando-se da técnica de \"Inflow Occlusion\". Tentou-se estabelecer normotermia dos animais durante os procedimentos cirúrgicos. Foram realizados exames hemogasométricos, e avaliações clínica e neurológica nos momentos preconizados. Alterações neurológicas transitórias foram observadas em ambos os grupos. Ocorreram dois óbitos transoperatórios no grupo B, e um animal do mesmo grupo apresentou cegueira permanente no período pós-operatório. Apesar da acidose metabólica observada durante os procedimentos, o pH, pressão parcial de dióxido de carbono no sangue arterial, e bicarbonato plasmático arterial de ambos os grupos, retornaram aos valores normais após trinta minutos da parada circulatória. Apesar das alterações observadas, é lícito afirmar que o \"Inflow Occlusion\" é seguro por até 7 minutos. Após este período, no entanto, é contra-indicado, segundo resultados obtidos e óbitos transoperatórios relatados. / \"Inflow Occlusion\" technique can be used in heart surgeries when heart is required to be opened just for few minutes, to allow quick repairs. However, circulatory arrest, event occasioned by this technique, can produce serious metabolic and neurologic consequences to the patient, and monitorization on trans, and postoperatory moments is well recommended. In this study, 12 mongrel dogs were used, and were divided into two groups, A and B, submmited to 7 and 8 minutes of total circulatory arrest, respectively, using \"Inflow Occlusion\" technique. Normothermia was tried during surgical procedures. Hemogasometric analysis, and clinical and neurological exams were made, each of them, on the moments established for the experiment. There were some transitory neurological problems related to both groups. There were two transoperatory deaths in group B and one case of permanent blindness in the same group, on postoperatory period. Despite metabolic acidosis occurred during procedures, pH values, arterial dioxide carbon parcial pressure, and arterial plasmatic bicarbonate related to both groups, returned to basal levels thirty minutes after surgery. Even occuring some hemogasometric and neurologic alterations, we can say that \"Inflow Occlusion\" is safe for periods up to 7 minutes. After this period of time, however, it is contraindicated, as seen after these results and because transoperatory deaths.

A técnica de \"Inflow Occlusion\" pode ser utilizada em cirurgias cardíacas quando se pretende manter o coração aberto apenas por alguns minutos, para realização de pequenos reparos. No entanto, a parada circulatória total, evento decorrente da técnica em questão, pode acarretar severas alterações metabólicas e neurológicas, sendo necessária monitorização trans e pósoperatória do paciente. Neste estudo foram utilizados 12 cães sem raça definida, os quais foram divididos em dois grupos, A e B, submetidos a 7 e 8 minutos de parada circulatória total, respectivamente, utilizando-se da técnica de \"Inflow Occlusion\". Tentou-se estabelecer normotermia dos animais durante os procedimentos cirúrgicos. Foram realizados exames hemogasométricos, e avaliações clínica e neurológica nos momentos preconizados. Alterações neurológicas transitórias foram observadas em ambos os grupos. Ocorreram dois óbitos transoperatórios no grupo B, e um animal do mesmo grupo apresentou cegueira permanente no período pós-operatório. Apesar da acidose metabólica observada durante os procedimentos, o pH, pressão parcial de dióxido de carbono no sangue arterial, e bicarbonato plasmático arterial de ambos os grupos, retornaram aos valores normais após trinta minutos da parada circulatória. Apesar das alterações observadas, é lícito afirmar que o \"Inflow Occlusion\" é seguro por até 7 minutos. Após este período, no entanto, é contra-indicado, segundo resultados obtidos e óbitos transoperatórios relatados. / \"Inflow Occlusion\" technique can be used in heart surgeries when heart is required to be opened just for few minutes, to allow quick repairs. However, circulatory arrest, event occasioned by this technique, can produce serious metabolic and neurologic consequences to the patient, and monitorization on trans, and postoperatory moments is well recommended. In this study, 12 mongrel dogs were used, and were divided into two groups, A and B, submmited to 7 and 8 minutes of total circulatory arrest, respectively, using \"Inflow Occlusion\" technique. Normothermia was tried during surgical procedures. Hemogasometric analysis, and clinical and neurological exams were made, each of them, on the moments established for the experiment. There were some transitory neurological problems related to both groups. There were two transoperatory deaths in group B and one case of permanent blindness in the same group, on postoperatory period. Despite metabolic acidosis occurred during procedures, pH values, arterial dioxide carbon parcial pressure, and arterial plasmatic bicarbonate related to both groups, returned to basal levels thirty minutes after surgery. Even occuring some hemogasometric and neurologic alterations, we can say that \"Inflow Occlusion\" is safe for periods up to 7 minutes. After this period of time, however, it is contraindicated, as seen after these results and because transoperatory deaths.

No description available.

A complexidade inerente ao processo de produção de energia apresenta um desafio aos especialistas quando estes se deparam com o dimensionamento e operação de sistemas de recursos hídricos. A produção energética de um sistema hidroelétrico depende fundamentalmente das séries de vazões afluentes às diversas usinas hidrelétricas do sistema. No entanto, a incerteza das vazões futuras e sua aleatoriedade são obstáculos que dificultam todo o planejamento da operação do sistema energético brasileiro. A inexistência de um software específico para análise de séries de vazões ocorridas nas usinas hidrelétricas, associada à importância desse tipo de dado no contexto energético, motivou a concepção de uma ferramenta gráafica para visualização e previsão desses dados. Acredita-se que a visualização desses dados por meio de representações apropriadas e altamente interativas possa promover hipóteses e revelar novas informações dos fenômenos associados a essas quantidades, melhorando a qualidade das decisões de planejamento do sistema energético. Este trabalho de mestrado apresenta em detalhes o sistema desenvolvido, chamado Power Map Explorer, e das técnicas nele implementadas / The complexity inherent to the process of energy production introduces a challenge to the experts when they are faced with dimension and operation of water resources systems. The energy production of a hidroeletric system depends on streamflow time series from hydroelectric plants located on different rivers of the system. However, the uncertainty and randomness of future streamflow series impose difficulties to the planning and operation of the brazilian energy system. The lack of a software suite to support the analysis of inflow series from hydroelectric plants, and the importance of this data in the energy context motivated the conception and implementation of a graphical tool to visualize and forecast this type data. The appropriate level of visualization and interaction with this type of data can spring new hypotheses and reveal new information, leading to performance improvement of the task of energetic planning. This work presents a software for visualization and forecast of inflow data series, the Power Map Explorer, in detail