Controlador preditivo não linear aplicado ao controle de golfadas em processos de produção de petróleo

Slugging is a well-known slugging phenomenon in multiphase flow, which may cause problems such as vibration in pipeline and high liquid level in the separator. It can be classified according to the place of its occurrence. The most severe, known as slugging in the riser, occurs in the vertical pipe which feeds the platform. Also known as severe slugging, it is capable of causing severe pressure fluctuations in the flow of the process, excessive vibration, flooding in separator tanks, limited production, nonscheduled stop of production, among other negative aspects that motivated the production of this work . A feasible solution to deal with this problem would be to design an effective method for the removal or reduction of the system, a controller. According to the literature, a conventional PID controller did not produce good results due to the high degree of nonlinearity of the process, fueling the development of advanced control techniques. Among these, the model predictive controller (MPC), where the control action results from the solution of an optimization problem, it is robust, can incorporate physical and /or security constraints. The objective of this work is to apply a non-conventional non-linear model predictive control technique to severe slugging, where the amount of liquid mass in the riser is controlled by the production valve and, indirectly, the oscillation of flow and pressure is suppressed, while looking for environmental and economic benefits. The proposed strategy is based on the use of the model linear approximations and repeatedly solving of a quadratic optimization problem, providing solutions that improve at each iteration. In the event where the convergence of this algorithm is satisfied, the predicted values of the process variables are the same as to those obtained by the original nonlinear model, ensuring that the constraints are satisfied for them along the prediction horizon. A mathematical model recently published in the literature, capable of representing characteristics of severe slugging in a real oil well, is used both for simulation and for the project of the proposed controller, whose performance is compared to a linear MPC

Avaliação do controle da diagênese na qualidade de reservatório siliciclástico do cenomaniano superior da formação Açu, sudoeste da bacia potiguar

The distribution of diagenetic alterations in Late Cenomanian siliciclastic reservoirs from Potiguar Basin was influenced by the stratigraphic framework and the depositional system. Seismic sections and geophysical logs of two wells drilled in the SW portion of the mentioned basin above register regional stratigraphic surfaces representing maximum floods related to a transgressive event. The sequential analysis of 80 m of drill core (~450 m deep) recognized nine depositional facies with an upwards granodecrescent standard piling that limits cycles with an erosional conglomeratic base (lag) overlain by intercalations of medium to very fine sandstones showing cross bedding (channel, planar and low angled) and horizontal bedding (plane-parallel , wave and flaser). The top of the cycles is marked by the deposition of pelites and the development of paleosoils and lagoons. The correlation of genetically related facies reveals associations of channel fillings, crevasse, and flood plains deposited in a transgressive system. Detailed descriptions of seventy nine thin sections aided by MEV-EBSD/EDS, DRX and stable isotope analyses in sandstones revealed an arcosian composition and complex textural arrays with abundant smectite fringes continuously covering primary components, mechanically infiltrated cuticles and moldic and intragrain pores. K-feldspar epitaxial overgrowth covers microcline and orthoclase grains before any other phase. Abundant pseudomatrix due to the compactation of mud intraclasts concentrate along the stratification planes, locally replaced by macrocristalline calcite and microcrystalline and framboidal pyrite. Kaolinite (booklets and vermicular), microcrystalline smectite, microcrystalline titanium minerals and pyrite replace the primary components. The intergrain porosity prevails over the moldic, intragrain and contraction porosities. The pores are poorly connected due to the presence of intergranular smectite, k-feldspar overgrowth, infiltrated mud and pseudomatrix. The sandstones were subjected to eodiagenetic conditions next to the surface and shallow burial mesodiagenetic conditions. The diagenetic alterations reduced the porosity and the permeability mainly due to the precipitation of smectite fringes, compactation of mud intraclasts onto the pseudomatrix and cementing by poikilotopic calcite characterizing different reservoir petrofacies. These diagenetic products acted as barriers and detours to the flow of fluids thus reducing the quality of the reservoir.

kit educacional para controle e supervisão aplicado a nível

PEREIRA, J. P. ; CASTRO, B. P. S. ; VALENTIM, R. A. M. . Kit Educacional para Controle e Supervisão Aplicado a Nível. Holos, Natal, v. 2, p. 68-72, 2009

Rede de controle em ambiente hospitalar: um protocolo multiciclos para automação hospitalar sobre IEEE 802.3 com IGMP Snooping

VALENTIM, R. A. M. ; MORAIS, A. H. F. ; SOUZA, V. S. V ; ARAUJO JUNIOR, H. B. ; BRANDAO, G. B. ; GUERREIRO, A. M. G. . Rede de Controle em Ambiente Hospitalar: um protocolo multiciclos para automação hospitalar sobre IEEE 802.3 com IGMP Snooping. Revista Ciência e Tecnologia, v. 11, p. 19, 2009

Utilizando a porta paralela para controle remoto de um dispositivo

VALENTIM, R. A. M.; NOGUEIRA, I. A.;ROCHA NETO, A. F. Utilizando a porta paralela para controle remoto de um dispositivo. Revista da FARN, Natal, v. 2, p. 103-114, 2002.

Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo

BRITTO, Ricardo S.; MEDEIROS, Adelardo A. D.; ALSINA, Pablo J. Uma arquitetura distribuída de hardware e software para controle de um robô móvel autônomo. In: SIMPÓSIO BRASILEIRO DE AUTOMAÇÃO INTELIGENTE,8., 2007, Florianópolis. Anais... Florianópolis: SBAI, 2007.

Controle social do espaço público: uma análise do conselho turístico pólo costa das dunas

The managing Conselho of public politics constitute one of the main experiences of democracy in Brazil contemporary representing a conquest for construction of a democratic institutionalism. The historical newness consists of the intensification and the institutionalization of the dialogue between government and society - in public and plural canals - as condition for an allocation more efficient joust and of the public resources. In this context the present study it objectified to understand from readings of the performance of represented group of bencheses the dynamics of functioning of the Tourist Conselho Pólo Costa das Dunas while space of participation and social control. The bibliographical research contemplated diverse sources in order to compile knowledge of credential authors in the quarrel of inherent subjects to the civil society and the public sphere to the construction of the citizenship to the conception formation and dynamics of the social control through Conselho of public politics. A qualitative perspective the case study was adopted as research method and for attainment of the data interviews with the members of the Conselho had been carried through beyond consultation the referring documents the dynamics of functioning of the Conselho. The profiles capacities and limitations of the members of the Conselho had been identified constitution social and dynamic organization of functioning of the Conselho and the readings of the members of the Conselho concerning the power to decide instances and participation. The results had shown that the allotment of being able in the Conselho does not occur of equal form. The functions of coordination of the activities of the Conselho are assumed by the representatives of the public agencies. Level of qualification of council members also if presents as difficulty to development of activities of Conselho since the majority of the interviewed ones disclosed unreliability and unfamiliarity when thematic specific that runs away from its organizacional reality they are boarded in the assemblies. Of this form the Conselho if presents more as half of institutional legitimation of what half of characterization of the creation of a public sphere properly said. Finally he could himself be concluded that a democratic culture inexists that inside crosses practical the institutional ones of the Conselho thus limiting the possibility to reach the effective social control of the public politics of tourism in the Rio Grande do Norte

A ouvidoria pública como instrumento de controle das ações da Secretaria de Saúde do Pará

The State and Public Administration have gone through several reforms in search of a quick operation and the provision of services with quality. With the democratization of the country and the issue of the Constitution in 1988, further reform of the State and Public Administration, joined the government agenda in 1995 and included among its objectives, the principles of participation and social control. In view of this, it raises the Public Ombudsman in order to be a channel for the participation of users in the management of public affairs, social control, transparency of administrative actions, improving the quality of service and meeting the needs of the community. The aim of this study is to assess whether the Ombudsman of the State Department of Public Health to contribute to the period 2006-2008, for the improvement of specialized consulting services. The research is characterized as descriptive, qualitative approach. The collection technique used was the interview, conducted with 37 service users and two servants of the Ombudsman. The analysis was developed based on the perception of users and servers in the opinion of the Ombudsman. The most relevant results of the research showed that 41% of users search the Ombudsman because they believed that solve the problem presented. However, even with this level of public acceptance, the Ombudsman reached average index of resolvability of 53% in the period. In his role has not developed mechanisms for quality control of services, which is mentioned by 67% of users. It turned out the same fact in relation to popular participation, which is confirmed by 84% of users. For 24% of users, the problems raised were resolved, and of these, 56% believe that the Ombudsman has contributed to the positive outcome. As a result of the search results, it appears that the Ombudsman's SESPA / PA, is not fulfilling its role to ensuring the democratization of articipation in management, social control and has limited contribution to solving the problems of users and to improve the quality of services

Vigilância eletrônica no trabalho bancário: do controle consentido ao totalitarismo corporativo

This dissertation addresses the electronic surveillance theme in the banking context. The research that originated it, which was held in an organization called for the fiction name Banco Total, started from the following driving question: How do workers at a bank perceive electronic surveillance at their process of work? The research s main objective was to comprehend how workers perceive electronic surveillance at their process of work. The study adopted an interdisciplinary perspective, having Management as the original field, establishing a dialogue with others disciplines, like Philosophy and Sociology. About its methodology, it s a qualitative research that addressed its object in oral (interviews with live history elements) way. . Ten individuals were interviewed. The analytical process utilized the hermeneutical-dialectics technique.. From the analyses (hermeneutics) of the data, the following themes have emerged: (i) Acquiescence ; (ii) Monitoring; (iii) Time and Motion; (iv) Fear; (v) Interdiction; and (vi) Resistance . From the discussion (dialectic) of the results, this work presents three synthetic propositions that culminate in the following dimensions (i) control; (ii) acquiescence; (iii) corporative totalitarianism. It can be concluded that electronic surveillance is one mechanism of control emerged from the apply of technology at Total Bank; that information technology has been improving the control mechanisms of management theories; and that the imbrications between management and material technology control mechanisms at a context where there is acquiescence by workers contribute for the emergency of corporative totalitarianism components

Relações entre mecanismos de coordenação e controle com desempenho organizacional: um estudo nas instituições públicas de ensino médio de Natal

This research aimed at relating coordination and control forms to organizational performance. The multicase study was applied in two public high schools: Centro Federal de Educação Tecnológica do Rio Grande do Norte and Floriano Cavalcanti. In order to accomplish these objectives, it was developed a qualitative analysis and considered coordination and control forms of several authors. Also was considered Sander´s (1984) model of organizational performance. The mentioned model considers two criteria to analyze organizational performance: one instrumental (efficiency and efficacy) and other substantive (effectiveness e relevance). The research attempts to show the importance of balancing these criteria in a way that effectiveness and relevance becomes more important at schools. It was proven that the use of bureaucratic coordination forms has the power to influence the evaluation on the instrumental technique. At the same time, it was observed that the use of mechanisms based on the autonomy of the school is related to efficiency and efficacy. The object of this research can be considered successful

Avaliação de produtos naturais no controle de biofilmes formados em sistema dinâmico

The biofilms microbial forms of association are responsible for generating, accelerating and / or induce the process of corrosion. The damage generated in the petroleum industry for this type of corrosion is significatives, representing major investment for your control. The aim of this study was to evaluate such tests antibiograms the effects of extracts of Jatropha curcas and essential oil of Lippia gracilis Schauer on microrganisms isolated from water samples and, thereafter, select the most effective natural product for further evaluation of biofilms formed in dynamic system. Extracts of J. curcas were not efficient on the complete inhibition of microbial growth in tests type antibiogram, and essential oil of L. gracilis Schauer most effective and determined for the other tests. A standard concentration of essential oil of 20 μL was chosen and established for the evaluation of the biofilms and the rate of corrosion. The biocide effect was determined by microbial counts of five types of microorganisms: aerobic bacteria, precipitating iron, total anaerobic, sulphate reducers (BRS) and fungi. The rate of corrosion was measured by loss of mass. Molecular identification and scanning electron microscopy (SEM) were performed. The data showed reduction to zero of the most probable number (MPN) of bacteria precipitating iron and BRS from 115 and 113 minutes of contact, respectively. There was also inhibited in fungi, reducing to zero the rate of colony-forming units (CFU) from 74 minutes of exposure. However, for aerobic and anaerobic bacteria there was no significant difference in the time of exposure to the essential oil, remaining constant. The rate of corrosion was also influenced by the presence of oil. The essential oil of L. gracilis was shown to be potentially effective

Controle preditivo neural aplicado à processos petroquímicos

A pesquisa tem como objetivo desenvolver uma estrutura de controle preditivo neural, com o intuito de controlar um processo de pH, caracterizado por ser um sistema SISO (Single Input - Single Output). O controle de pH é um processo de grande importância na indústria petroquímica, onde se deseja manter constante o nível de acidez de um produto ou neutralizar o afluente de uma planta de tratamento de fluidos. O processo de controle de pH exige robustez do sistema de controle, pois este processo pode ter ganho estático e dinâmica nãolineares. O controlador preditivo neural envolve duas outras teorias para o seu desenvolvimento, a primeira referente ao controle preditivo e a outra a redes neurais artificiais (RNA s). Este controlador pode ser dividido em dois blocos, um responsável pela identificação e outro pelo o cálculo do sinal de controle. Para realizar a identificação neural é utilizada uma RNA com arquitetura feedforward multicamadas com aprendizagem baseada na metodologia da Propagação Retroativa do Erro (Error Back Propagation). A partir de dados de entrada e saída da planta é iniciado o treinamento offline da rede. Dessa forma, os pesos sinápticos são ajustados e a rede está apta para representar o sistema com a máxima precisão possível. O modelo neural gerado é usado para predizer as saídas futuras do sistema, com isso o otimizador calcula uma série de ações de controle, através da minimização de uma função objetivo quadrática, fazendo com que a saída do processo siga um sinal de referência desejado. Foram desenvolvidos dois aplicativos, ambos na plataforma Builder C++, o primeiro realiza a identificação, via redes neurais e o segundo é responsável pelo controle do processo. As ferramentas aqui implementadas e aplicadas são genéricas, ambas permitem a aplicação da estrutura de controle a qualquer novo processo

Controle aplicado a poços com método de elevação e bombeio centrífugo submerso

The Electrical Submersible Pumping is an artificial lift method for oil wells employed in onshore and offshore areas. The economic revenue of the petroleum production in a well depends on the oil flow and the availability of lifting equipment. The fewer the failures, the lower the revenue shortfall and costs to repair it. The frequency with which failures occur depends on the operating conditions to which the pumps are submitted. In high-productivity offshore wells monitoring is done by operators with engineering support 24h/day, which is not economically viable for the land areas. In this context, the automation of onshore wells has clear economic advantages. This work proposes a system capable of automatically control the operation of electrical submersible pumps, installed in oil wells, by an adjustment at the electric motor rotation based on signals provided by sensors installed on the surface and subsurface, keeping the pump operating within the recommended range, closest to the well s potential. Techniques are developed to estimate unmeasured variables, enabling the automation of wells that do not have all the required sensors. The automatic adjustment, according to an algorithm that runs on a programmable logic controller maintains the flow and submergence within acceptable parameters avoiding undesirable operating conditions, as the gas interference and high engine temperature, without need to resort to stopping the engine, which would reduce the its useful life. The control strategy described, based on modeling of physical phenomena and operational experience reported in literature, is materialized in terms of a fuzzy controller based on rules, and all generated information can be accompanied by a supervisory system

Potencial larvicida de extratos de plantas regionais no controle de larvas de Aedes aegypti

Dengue, amongst the virus illnesses one can get by vectorial transmission, is the one that causes more impact in the morbidity and mortality of world s population. The resistance to the insecticides has caused difficulties to control of vector insect (Aedes aegypti) and has stimulated a search for vegetables with larvicidal activity. The biodiversity of Caatinga is barely known and it is potential of use even less. Some plants of this biome are commercialized in free fairs northeast of Brazil, because of its phytotherapics properties. The vegetables in this study had been selected by means of a questionnaire applied between grass salesmen and natives of the Serido region from Rio Grande do Norte state; culicids eggs had been acquired with traps and placed in container with water for the larva birth. Thirty larvae had been used in each group (a group control and five experimental groups), with four repetitions four times. The vegetables had been submitted to the processes of decoction, infusion and maceration in the standard concentration of 100g of the vegetable of study in 1l of H2O and analyzed after ½, 1, 2, 4, 8, 12, 24 and 48 hours for verification of the average lethal dose (LD50) from the groups with thirty larva. The LD50 was analyzed in different concentrations (50g/l, 100g/l, 150g/l, 200g/l e 300g/l) of Aspidosperma pyrifolium Mart. 48 extracts of rind, leaf and stem of the seven vegetal species: Aspidosperma pyrifolium Mart., Mimosa verrucosa Benth, Mimosa hostilis (Mart.) Benth., Myracrodruon urundeuva Allemão, Ximenia americana L, Bumelia sartorum Mart Zizyphus joazeiro Mart, had been analyzed. The extracts proceeding from the three methods were submitted to the freezedrying, to evaluate and to quantify substances extracted in each process. The results had shown that Aspidosperma pyrifolium Mart. and Myracrodruon urundeuva Allemão are the species that are more distinguished as larvicidal after 24 hours of experiment, in all used processes of extraction in the assays. The Zizyphus joazeiro Mart species has not shown larvicidal activity in none of the assays. In relation to the extraction method, the decoction was the most efficient method in the mortality tax of the A. aegypti larvae

Abordagem psicossociologica das implicações legais da infecção hospitalar e de seu controle

Pesquisas acerca das Infecções Hospitalares mostram a gravidade do problema na saúde e a existência de poucos profissionais das áreas do Direito e da Saúde especializados nas implicações jurídicas relacionadas com o controle das Infecções Hospitalares. Assim, este estudo multidisciplinar tem como objetivos: apreender as Representações Sociais das Implicações Jurídicas das Infecções Hospitalares e de seu Controle, elaboradas pelos profissionais do direito e da saúde e analisar o impacto destas representações sobre Infecções Hospitalares e seu controle no âmbito do Hospital Getúlio Vargas, em Teresina, no Estado do Piauí. Trata-se de um estudo de caráter exploratório, desenvolvido em hospital público com profissionais do Direito e da Saúde, subsidiado na Teoria das Representações Sociais, de Serge Moscovici. Os dados foram coletados através de entrevista em profundidade e da observação. As informações apreendidas foram processadas no software Alceste 4.8, possibilitando a análise lexical e estatística pela Classificação Hierárquica Descendente, que permitiu identificar no discurso classes representativas de palavras de interesse da investigação. Os resultados indicaram que os sujeitos do estudo, através das suas representações sociais, defendem os direitos dos usuários da saúde e conhecem a prática das políticas de saúde, prevenção das Infecções Hospitalares e de seu Controle. Porém, demonstraram pouca preocupação com as implicações jurídicas inerentes às sua práticas mesmo estando sujeitos a responder civil e penalmente pelas ocorrências geradas por iatrogenia no exercício da profissão