Cinemática de partículas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo: avaliação durante paradas operacionais

The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well

Estudo dos parâmetros operacionais do processo de combustão in situ em reservatório de petróleo pesado

The occurrence of heavy oil reservoirs have increased substantially and, due to the high viscosity characteristic of this type of oil, conventional recovery methods can not be applied. Thermal methods have been studied for the recovery of this type of oil, with a main objective to reduce its viscosity, by increasing the reservoir temperature, favoring the mobility of the oil and allowing an increasing in the productivity rate of the fields. In situ combustion (ISC) is a thermal recovery method in which heat is produced inside the reservoir by the combustion of part of the oil with injected oxygen, contrasting with the injection of fluid that is heated in the surface for subsequent injection, which leads to loss heat during the trajectory to the reservoir. The ISC is a favorable method for recovery of heavy oil, but it is still difficult to be field implemented. This work had as an objective the parametric analysis of ISC process applied to a semi-synthetic reservoir with characteristics of the Brazilian Northeast reservoirs using vertical production and vertical injection wells, as the air flow injection and the wells completions. For the analysis, was used a commercial program for simulation of oil reservoirs using thermal processes, called Steam, Thermal and Advanced Processes Reservoir Simulator (STARS) from Computer Modelling Group (CMG). From the results it was possible to analyze the efficiency of the ISC process in heavy oil reservoirs by increasing the reservoir temperature, providing a large decrease in oil viscosity, increasing its mobility inside the reservoir, as well as the improvement in the quality of this oil and therefore increasing significantly its recovered fraction. Among the analyzed parameters, the flow rate of air injection was the one which had greater influence in ISC, obtaining higher recovery factor the higher is the flow rate of injection, due to the greater amount of oxygen while ensuring the maintenance of the combustion front

Identificação remota de sistemas operacionais utilizando análise de processos aleatórios e redes neurais artificiais

A new method to perform TCP/IP fingerprinting is proposed. TCP/IP fingerprinting is the process of identify a remote machine through a TCP/IP based computer network. This method has many applications related to network security. Both intrusion and defence procedures may use this process to achieve their objectives. There are many known methods that perform this process in favorable conditions. However, nowadays there are many adversities that reduce the identification performance. This work aims the creation of a new OS fingerprinting tool that bypass these actual problems. The proposed method is based on the use of attractors reconstruction and neural networks to characterize and classify pseudo-random numbers generators

Avaliação dos efeitos agudos de diferentes niveis de PEP sobre o padrão respiratório e volumes operacionais de pacientes com Parkinson

Objetivo: Determinar os efeitos agudos de diferentes intensidades de pressão expiratória positiva sobre o padrão respiratório e volumes operacionais de pacientes com doença de Parkinson. Métodos: Foram eleitos para o estudo 23 pacientes em estágios II ou III da doença, estando na condição ON , sendo 8 excluídos, e 15 controles saudáveis. Os indivíduos foram submetidos a uma avaliação inicial, constando de dados gerais, avaliação antropométrica, função pulmonar e força muscular respiratória. Após esta etapa inicial, realizou-se a avaliação dos volumes pulmonares com pletismografia optoeletrônica associado a utilização de pressão expiratória positiva (PEP) em três intensidades de pressão positiva, 10 cmH2O, 15 cmH2O e 20 cmH2O em ordem aleatória. Resultados: O grupo Parkinson apresentou valores espirométricos e de força muscular respiratória significativamente menores que o grupo controle (p<0.01). Houve diferença nos valores de volume corrente (Vt) do grupo Parkinson em relação ao grupo controle na respiração tranqüila (p<0.001) e aumento no Vt do grupo Parkinson com uso das três intensidades de PEP (p<0.001), sem diferenças estatisticamente significativas entre as intensidades e com diferença na distribuição compartimental do Vt entre os grupos (p<0.001). O fluxo inspiratório médio e o volume minuto do grupo Parkinson foram menores em relação ao grupo controle na respiração tranqüila (p<0.001) e aumentaram com o uso das três intensidades de PEP (p<0.001), sem diferenças estatisticamente significativas entre as intensidades. Houve diferença na variação dos volumes operacionais entre os grupos em todas as intensidades de PEP (p < 0.001). O volume pulmonar expiratório final não aumentou no grupo Parkinson com uso de PEP. O volume pulmonar inspiratório final aumentou no grupo Parkinson em todas intensidades de PEP (p < 0.001), não havendo diferenças entre as intensidades. Conclusão: Os pacientes com doença de Parkinson apresentam alterações em diferentes componentes do padrão respiratório e a terapia com PEP determina modificações clinicamente importantes nos volumes pulmonares, considerando a intensidade de 10 cmH2O suficientes para este objetivo terapêutico

Benchmarking e regulação do setor de distribuição de energia elétrica nacional: proposta para avaliação dos custos operacionais eficientes

In Brazil, the National Agency of Electric Energy (ANEEL) represents the energy regulator. The rates review have been one of its main tasks, which establish a pricing practice at a level to cover the efficient operating costs and also the appropriate return of the distributors investments. The changes in the procedures to redefine the efficient costs and the several studies on the methodologies employed to regulate this segment denote the challenge faced by regulators about the best methodological strategy to be employed. In this context, this research aims to propose a benchmarking evaluation applied to the national regulation system in the establishment of efficient operating costs of electricity distribution utilities. The model is formulated to promote the electricity market development, partnering with government policies ant to society benefit. To conduct this research, an integration of Data Envelopment Analysis (DEA) with the Stochastic Frontier Analysis (SFA) is adopted in a three stages procedure to correct the efficiency in terms of environmental effects: (i) evaluation by means of DEA to measure operating costs slacks of the utilities, in which environmental variables are omitted; (ii) The slacks calculated in the first stage are regressed on a set of environmental variables by means of SFA and operating costs are adjusted to account the environmental impact and statistical noise effects; and, (iii) reassess the performance of the electric power distribution utilities by means of DEA. Based on this methodology it is possible to obtain a performance evaluation exclusively expressed in terms of management efficiency, in which the operating environment and statistical noise effects are controlled.

Implementação das diretrizes operacionais para a educação básica nas escolas do campo: embates e limitações do trabalho docente no Rio Grande do Norte

Considering the situation of neglect existing in Brazilian public education and, specially, in the process of rural schooling, this dissertation aims to analyze the process of implementation of the Operational Guidelines for Basic Education in Rural Schools (DOEBEC), regulatory framework of the national policy of rural education. On it, we analyze the conditions of teaching work in rural schools of Rio Grande do Norte (RN), in 2010. The sample of the survey has as reference the representativeness of the chosen universe in relation to the totality of rural schools belonging to the state of RN. To answer the goals of the research, we opted to present a critical analysis of the following points: 1) Implementation of the DOEBEC; 2) Conditions of teaching work and teaching training. The points or categories of research were chosen based in the determinations of the DOEBEC (Resolution CNE/CEB n. 01/2002). For the data collection in the referred schools, we opted for the realization of interviews with the teachers and managers of these teaching establishments, in 2010. It was also utilized, for the characterization of school attendance in rural schools of RN, in 2010, official statistical data available by the State Secretary of Education and Culture (SEEC/RN). The analysis of the statistical data and of the primary data collected in field research indicated that the conditions of teaching work are still an obstacle to the development of the educative work of the teacher in rural areas. According to interviews with the participants of the research, we realized that the DOEBEC, despite being sanctioned in 2002, were still dimly known and discussed by the interviewees of the referred schools in 2010. Thus, we propose that the implementation of the policy of rural education in RN, instituted by DOEBEC’s legal landmark, and reaffirmed by the Rio Grande do Norte’s Charter to Rural Education (Brazil, 2005), is rethought and reconsidered, in the sense of ensuring that the changes proposed in this legal text, inherent to the school functioning, to the conditions of teaching work, to the rural schools’ management, to the remuneration and valorization of teaching work, to the teaching training, to the conditions of school transport, among others, be turned into concrete actions to improve the quality of education offered in the rural schools of RN state.

Implementação das diretrizes operacionais para a educação básica nas escolas do campo: embates e limitações do trabalho docente no Rio Grande do Norte

Considering the situation of neglect existing in Brazilian public education and, specially, in the process of rural schooling, this dissertation aims to analyze the process of implementation of the Operational Guidelines for Basic Education in Rural Schools (DOEBEC), regulatory framework of the national policy of rural education. On it, we analyze the conditions of teaching work in rural schools of Rio Grande do Norte (RN), in 2010. The sample of the survey has as reference the representativeness of the chosen universe in relation to the totality of rural schools belonging to the state of RN. To answer the goals of the research, we opted to present a critical analysis of the following points: 1) Implementation of the DOEBEC; 2) Conditions of teaching work and teaching training. The points or categories of research were chosen based in the determinations of the DOEBEC (Resolution CNE/CEB n. 01/2002). For the data collection in the referred schools, we opted for the realization of interviews with the teachers and managers of these teaching establishments, in 2010. It was also utilized, for the characterization of school attendance in rural schools of RN, in 2010, official statistical data available by the State Secretary of Education and Culture (SEEC/RN). The analysis of the statistical data and of the primary data collected in field research indicated that the conditions of teaching work are still an obstacle to the development of the educative work of the teacher in rural areas. According to interviews with the participants of the research, we realized that the DOEBEC, despite being sanctioned in 2002, were still dimly known and discussed by the interviewees of the referred schools in 2010. Thus, we propose that the implementation of the policy of rural education in RN, instituted by DOEBEC’s legal landmark, and reaffirmed by the Rio Grande do Norte’s Charter to Rural Education (Brazil, 2005), is rethought and reconsidered, in the sense of ensuring that the changes proposed in this legal text, inherent to the school functioning, to the conditions of teaching work, to the rural schools’ management, to the remuneration and valorization of teaching work, to the teaching training, to the conditions of school transport, among others, be turned into concrete actions to improve the quality of education offered in the rural schools of RN state.

Cinemática de partículas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo: avaliação durante paradas operacionais

The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well

Estudo dos parâmetros operacionais do processo de combustão in situ em reservatório de petróleo pesado

The occurrence of heavy oil reservoirs have increased substantially and, due to the high viscosity characteristic of this type of oil, conventional recovery methods can not be applied. Thermal methods have been studied for the recovery of this type of oil, with a main objective to reduce its viscosity, by increasing the reservoir temperature, favoring the mobility of the oil and allowing an increasing in the productivity rate of the fields. In situ combustion (ISC) is a thermal recovery method in which heat is produced inside the reservoir by the combustion of part of the oil with injected oxygen, contrasting with the injection of fluid that is heated in the surface for subsequent injection, which leads to loss heat during the trajectory to the reservoir. The ISC is a favorable method for recovery of heavy oil, but it is still difficult to be field implemented. This work had as an objective the parametric analysis of ISC process applied to a semi-synthetic reservoir with characteristics of the Brazilian Northeast reservoirs using vertical production and vertical injection wells, as the air flow injection and the wells completions. For the analysis, was used a commercial program for simulation of oil reservoirs using thermal processes, called Steam, Thermal and Advanced Processes Reservoir Simulator (STARS) from Computer Modelling Group (CMG). From the results it was possible to analyze the efficiency of the ISC process in heavy oil reservoirs by increasing the reservoir temperature, providing a large decrease in oil viscosity, increasing its mobility inside the reservoir, as well as the improvement in the quality of this oil and therefore increasing significantly its recovered fraction. Among the analyzed parameters, the flow rate of air injection was the one which had greater influence in ISC, obtaining higher recovery factor the higher is the flow rate of injection, due to the greater amount of oxygen while ensuring the maintenance of the combustion front