66 resultados para Formações ferríferas

em Universidade Federal do Rio Grande do Norte(UFRN)


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The central research question was to search for data to ratify the theory and discourse of the so-called practitioners of economic solidarity, by defending the substantive rationality should guide the principles of economic solidary, designing the space economy incidental and not the primacy of relations in determining social as well, reflecting the predominance of dimensions of social management in administrative practices of ESS's. For both analyzed the theoretical dimensions of social management - sociopolitical, economic, organizational and environmental - manifested in organizational practices supportive of economic organization Potiguar West. For the success of the research realized the triangulation involving a combination of quantitative and qualitative methodological approaches. At first the research will use a quantitative approach, from the cluster analysis, to verify the behavior of the sample chosen for this study. In the second stage of the qualitative study was carried out focus group technique (FLICK, 2002) for further analysis of the dimensions of social management on organizational practices supportive of economic organization, related to the principles of Solidary Economy, established in a quantitative approach. In quantitative analysis, the socio-political dimension, it was clear that the more equity instruments of internal and external, from the purposeful living in public spaces, the best monetary results. Another point worth stressing concerns the economic dimension, with the practice reciprocity prevailing in market. Thus, the qualitative approach was possible to understand the processes of exchange of product or service. Rural enterprises surveyed in the allocation of the agro-ecological products have the following scale of priority, sequentially: self-consumption (domestic), market and exchange. The research leads to the fact that training and practices that enhance the socio-political dimension (knowledge, empowerment, sense of belonging) become the guiding principle for the strengthening of the social management in the context of other dimensions, leading to gains sociopolitical, economic, organizational and environmental. Despite the weaknesses found in the organizational dimension and environment, both in a quantitative as in qualitative, we determined that the practices of ESS's Potiguar West incorporate predominantly elements of social management and economic solidarity, with a preponderance of substantive rationality in the primacy of the instrumental. Finally, research has brought information that the participants of the ESS's do not give the money economy primacy in determining social relations, which in turn leads to the confirmation that, in practice the solidarity economy, prevailing the dominance of substantive rationality, as a guide for organizational practices

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The Women s experiences in the private sphere under the work s field changes the family relationship allowing them more freedom, autonomy and independence. The inequalities, socially built, homemade women s obligations results in discrimination, difficult to insert and recovery on female s job in a job s market, including low salary if compared with men s and difficult to services access in addiction a difficult daily life and in domestic sphere. The women s organisation in productive groups or economically solidary enterprises (ESE) torn possible the social economically organisations and politicians to promote deep changes in a domestically e socially relationship, positioning, for example, women s in publics areas and in the rout of emancipation. The objective of this search are understand men and women relationship in the family agriculture s field starts insert women in economically solidary enterprises (ESE) on Mulunguzinho s settlement (Mossoró/RN). The theoretical framework is inspirited Economical Solidary concept kind division s job and women s empowerment. This search had a qualitative character and exploration through case s study on Mulheres decididas a vencer s group. The secondary information was create through theoretical framework and information collected through semi-structured interviews based in interviews applied for women and yours respective husbands by criterion for women participation on productive activities of beekeeping culture of goat and sheep. This study turns possible conclude that the women s participations in productive groups in solidary economical change significantly their life and their family life. The group s organisations process, the training was received, the collective production, the marketing and the mobilized participation to move it all was fundamental for women share with their families partners some homemade and take care with the children. This finding confirm a different aspect not economical in solidary economy overcoming the monetary value in associative relationship observing principally individuals well-being and the concern with the form of reproduction this way of life in the associated

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Oil well cementing materials consist of slurries of Special class Portland cement dispersed in water. Admixtures can be used to provide the necessary fluidity, so the material can be efficiently pumped down as well as penetrate porous rocks with controlled filter loss. Construction admixtures can be used to modify the properties of oil well cements provided they can withstand and hold their properties at the higher than ambient temperatures usually encountered in oil fields. In civil construction, superplasticizer play the role of dispersants that reduce the facto r of water cement improve mechanical properties and fluidity of the cement, whereas anti-segregation agents improve the workability of the slurry. In the present study, oil well cement slurries were produced adding both a dispersant and an anti-segregation agent conventionally used in Portland CPII-Z-32 RS cement aiming at materials for primary cementing and squeeze operations. Three basic aspects were evaluated: fluidity, filter loss and the synergetic effect of the admixtures at two temperatures, i.e., 27°C and 56°C, following API RP 10B practical recommendations. The slurries were prepared using admixture concentrations varying from 2.60 Kgf/m3 (0.02 gallft3) to 5.82 Kgf/m3 (0.045 galJft3) BWOC. The density of the slurries was set to 1.89 g/cm3 (15.8 Ib/gal). 0.30 to 0.60% BWOC of a CMC-based anti-segregation agent was added to the cement to control the filter loss. The results showed that the addition of anti-segregation at concentrations above 0.55% by weight of cement resulted in the increased viscosity of the folders in temperatures evaluated. The increasing the temperature of the tests led to a reduction in the performance of anti-segregation. At concentrations of 5.20 kgf/m3 (0,040 gallft3) and 5.82 Kgf/m3 (0,045 gal/ft 3) observed a better performance of the properties evaluated in the proposed system. At low temperature was observed instability in the readings of rheology for all concentrations of anti-segregation. Contents that increasing the concentration of anti¬-segregation is limited concentrations greater than 0.55 % BWOC of the CMC in temperature analyzed. The use of the system with CMC promoted a good performance against the properties evaluated. The principal function of anti¬-segregation was optimized with increasing concentration of superplasticizer, at temperatures above the 2rC. The study of the behaviour of systemic additives, resulting in slurries of cement, which can be optimized face studies of other intrinsic properties in oil fields

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One of the major current challenges for oilwell companies is the extraction of oil from evaporitic zones, also known as pre-salt basins. Deep reservoirs are found under thick salt layers formed from the evaporation of sea water. Salt layers seal the flow of oil from underneath rock formations, which store hydrocarbons and increase the probability of success in oil and gas exploration. Oilwells are cemented using Portland-based slurries to promote mechanical stability and zonal isolation. For pre-salt oilwells, NaCl must be added to saturate the cement slurries, however, the presence of salt in the composition of slurries affects their overall behavior. Therefore, the objective of the present study was to evaluate the effect of the addition of 5 to 25% NaCl on selected properties of Portland-based slurries. A series of tests were carried out to assess the rheological behavior, thickening time, free water and ultrassonic compressive strength. In addition, the slurries were also characterized by thermal analysis, X ray diffraction and scanning electron microscopy. The results showed that the addition of NaCl affected the thickening time of the slurries. NaCl contents up to 10% shortened the thickening time of the slurries. On the other hand, concentrations in excess of 20% not only extended the thickening time, but also reduced the strength of hardened slurries. The addition of NaCl resulted in the formation of a different crystalline phase called Friedel´s salt, where free chlorine is bonded to tricalcium aluminate

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One of the great challenges at present time related with the materials area concerns of products and processes for use in petroleum industry, more precisely related to the Pre-salt area. Progresses were reached in the last years allowing the drilling of the salt layer, with the time reduction for drilling and larger success at the end. For the oil wells companies the preponderant factor is the technology, however, in spite of the progress, a series of challenges is still susceptible to solutions and one of them refers to the slurries preparation for cementing in those areas. Inside of this context, this study had for objective to analyze the influence of the salts NaCl, KCl, CaSO4 and MgSO4 in strength and chemical structure of the hydrated products. As methodology, they were prepared and analyzed cement slurries with varied concentrations of these salts that are commonly found in the saline formations. The salts concentrations used in formulations of the slurries were of 5%, 15% and 30%. The slurries were formulated with specific weight of 15,8 lb / gal and the cement used was Class G. Strength tests were accomplished in samples cured by 24 hours and 28 days. Also were realized crystallographic characterization (XRD) and morphologic (SEM). In agreement with the presented results, it is observed that the largest resistance values are attributed to the slurries with concentration of 15%. There was reduction of the strength values of the slurries formulated with concentration of 30%. Through the characterization microstructural it was possible to note the salts influence in the main cement hydrated products

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Lightweight oilwell cement slurries have been recently studied as a mean to improve zonal isolation and sheath-porous formation adherence. Foamed slurries consisting of Portland cement and air-entraining admixtures have become an interesting option for this application. The loss in hydrostatic pressure as a consequence of cement hydration results in the expansion of the air bubbles entrapped in the cement matrix, thus improving the sheath-porous formation contact. Consequently, slurries are able to better retain their water to complete the hydration process. The main objective of the present study was to evaluate the effect of the addition of an air-entraining admixture on the density, stability and permeability of composite slurries containing Portland cement and diatomite as light mineral load. Successful formulations are potential cementing materials for low fracture gradient oilwells. The experimental procedures used for slurry preparation and characterization were based on the American Petroleum Institute and ABNT guidelines Slurries containing a pre-established concentration of the air-entraining admixture and different contents of diatomite were prepared aiming at final densities of 13 to 15 lb/gal. The results revealed that the reduction of 15 to 25% of the density of the slurries did not significantly affect their strength. The addition of both diatomite and the air-entraining admixture increased the viscosity of the slurry providing better air-bubble retention in the volume of the slurry. Stable slurries depicted bottom to top density variation of less than 1.0 lb/gal and length reduction of the stability sample of 5.86 mm. Finally, permeability coefficient values between 0.617 and 0.406 mD were obtained. Therefore, lightweight oilwell cement slurries depicting a satisfactory set of physicochemical and mechanical properties can be formulated using a combination of diatomite and air-entraining admixtures for low fracture gradient oilwells

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One of the major challenges faced nowadays by oil companies is the exploration of pre-salt basins. Thick salt layers were formed in remote ages as a consequence of the evaporation of sea water containing high concentrations of NaCl and KCl. Deep reservoirs can be found below salt formations that prevent the outflow of oil, thus improving the success in oil prospection. The slurries used in the cement operations of salt layers must be adequate to the properties of those specific formations. At the same time, their resulting properties are highly affected by the contamination of salt in the fresh state. It is t herefore important to address the effects of the presence of salt in the cement slurries in order to assure that the well sheath is able to fulfill its main role to provide zonal isolation and mechanical stability. In this scenario, the objective of the present thesis work was to evaluate the effect of the presence of NaCl and KCl premixed with cement and 40% silica flour on the behavior of cement slurries. Their effect in the presence of CO2 was also investigated. The rheological behavior of slurries containing NaCl and KCl was evaluated along with their mechanical strength. Thermal and microstructural tests were also carried out. The results revealed that the presence of NaCl and KCl affected the pozzolanic activity of silica flour, reducing the strength of the hardened slurries containing salt. Friedel´s salt was formed as a result of the bonding between free Cl- and tricalcium aluminate. The presence of CO2 also contributed to the degradation of the slurries as a result of a process of carbonation/bicarbonataion

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Pastas a base de cimento Portland são utilizadas na cimentação de poços de petróleo. Elas consistem de uma mistura de partículas sólidas de cimento dispersas em água e aditivos. Atualmente, diversos materiais alternativos são utilizados como aditivos, objetivando a modificação e a melhoria das propriedades das pastas de cimento, especialmente no aumento da fluidez. Novos aditivos plastificantes são capazes de suportar as diversas condições de poços, promovendo propriedades no estado fluido compatíveis às condições exigidas para cimentação.Dispersantes são os componentes da pasta que garantem fluidez, além de proporcionar controle na água perdida por filtração na formação porosa, garantindo o sucesso da operação de bombeio. Em deter minados campos, além do efeito da profundidade, as condições geológicas das formações promovemvariações do gradiente de pressão e temperatura ao longo da profundidade vertical do poço. Recentemente, diversos aditivos químicos da indústria da construção civil tem sido estudados em condições de cimentação de poços de petróleo. Vários produtos testados tem apresentado desempenho superior aos produtos normalmente empregados pela indústria de petróleo com boa relação custo/benefício em função do volume de mercado da construção civil. Resultados promissores na seleção de aditivos com função dispersante da construção civil para operações de cimentação de poços de petróleo onshore foram obtidos para temperaturas até 80°C. O potencial de uso desses aditivos permite estabelecer novas soluções para problemas encontrados na cimentação de poços de petróleo HPHT, poços sujeitos à injeção de vapor, poços depletados e poços produtores de gás. Na construção civil, os superplastificantes permitem reduzir o fator água/cimento das argamassas proporcionando melhoria de propriedades como resistência mecânica e fluidez. Assim, o objetivo deste trabalho foi o estudo e a caracterização reológica de pastas constituídas de cimento Portland, água e aditivos do tipo plastificante, com função dispersante a base de naftaleno condensado e policarboxilato, na faixa de temperaturas de 58°C e 70ºC. As condições utilizadas para a avaliação dos aditivos alternativos foram baseadas em uma cimentação primária para um poço hipotético de 2200 m de profundidade e gradientes geotérmicos de 1,7°F/100 pés e 2,1°F/100 pés. Os resultados demonstraram a grande eficiência e o poder dispersivo do policarboxilato para as temperaturas estudadas. O aditivo promoveu alta fluidez, sem efeitos de sedimentação da pasta. O dispersante à base de naftaleno reduziutant o a viscosidade plástica como o limite de escoamento acimada concentração a partir de 0,13%. O modelo de Bingham descreveu bem o comportamento reológico das pastas com policarboxilato para todas as concentrações

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Os poços HPHT atravessam zonas anormalmente pressurizadas e com altos gradientes de temperatura. Esses poços apresentam elevadas concentrações de tensões produzidas pelas operações de perfuração e fraturamento hidráulico, flutuações da pressão e temperatura, forças dinâmicas geradas durante a perfuração, formações inconsolidadas, entre outros aspectos, podendo resultar em falhas mecânicas na bainha de cimento. Tais falhas comprometem a estabilidade mecânica do poço e o isolamento das zonas produtoras de óleos e/ou gás. Para que operações corretivas não se façam necessárias, é preciso adequar as pastas às condições de cada poço. Sistemas de pastas de cimento para poços HPHT requerem um bom controle de suas propriedades termo-mecânicas. Visto que a temperaturas superiores a 110 oC (230 oF) o cimento, após alcançar um valor máximo de resistência, inicia um processo de perda de resistência (retrogressão). Para prevenir esse efeito substitui-se parcialmente o cimento Portland por sílica com objetivo de incrementar a reação pozolânica. Esta reação modifica a trajetória do processo natural de hidratação do cimento, o gel de silicato de cálcio hidratado (C-S-H) se converte em várias outras fases com maior resistência. Polímeros também são adicionados para proporcionar maior flexibilidade e agir como barreira à propagação de trincas desenvolvidas sob tensão. O presente trabalho teve como objetivo estudar o comportamento do sistema cimento/sílica/polímero quando submetido às condições de alta temperatura e alta pressão. Foram formuladas pastas de cimento puro, pastas contendo 40 % BWOC de sílica flour e pastas com diferentes concentrações de poliuretana (5 % a 25 %) e 40 % BWOC de sílica flour. O peso específico das pastas foi fixado em 1,87 g/cm3 (15,6 lb/gal). Os resultados demonstram que as resistências da pasta contendo 40% de sílica e das com adição de polímero foram muito superiores a da pasta de cimento puro, não ocorrendo o efeito da retrogressão. As pastas com polímero apresentaram um crescente aumento da tenacidade com o aumento da concentração da mesma, sendo assim capaz de suportar as tensões. Além de se manterem estáveis termicamente acima de 180 ºC. O sistema também apresentou excelentes resultados de filtrado, reologia, água livre, estabilidade e permeabilidade. Sendo assim, o mesmo mostrou ser aplicável a poços HPHT

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Cementing operations may occur at various stages of the life cycle of an oil well since its construction until its definitive abandonment. There are some situations in which the interest zones are depleted or have low fracture pressure. In such cases, the adoption of lowdensity cement slurries is an efficient solution. To this end, there are basically three ways to reduce the density of cement slurries: using microspheres, water extending additives or foamed cement. The objective of this study is to formulate, to study and to characterize lowdensity foamed cement, using an air entrainment surfactant with vermiculite or diatomite as water extenders and stabilizers. The methodology consists on preparation and evaluation of the slurries under the American Petroleum Institute (API) and the Brazilian Association of Technical Standards (ABNT) guidelines. Based on calculated densities between 13 and 15 ppg (1.559 and 1.799 g/cm3), the slurries were prepared with fixed surfactant concentration, varying the concentrations of vermiculite and diatomite and were compared with the base slurries. The results of plastic viscosity, yield point and gel strength and the compressive strength for 24 h showed that the slurries presented suitable rheology and mechanical strength for cementing operations in oil wells, and had their densities reduced between 8.40 and 11.89 ppg (1.007 and 1.426 g/cm3). The conclusion is that is possible, under atmospheric conditions, to obtain light weighted foamed cement slurries with satisfactory rheological and mechanical properties by means of air entrainment and mineral additions with extenders and stabilizers effects. The slurries have great potential for cementing operations; applicability in deep wells, in low fracture gradient formations and in depleted zones and bring cost savings by reducing the cementing consumption

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Este estudo faz uma abordagem sobre as alianças eleitorais, destacando duas vertentes importantes nos processos de suas formações nas arenas políticas. Na primeira parte do trabalho é feita uma análise mais geral a respeito da problemática em questão. Onde dois ciclos políticos são analisados, apresentando o comportamento político-partidário dos partidos no Brasil. No primeiro ciclo, uma breve compreensão da política café-com-leite na República Velha, na qual, PRP e PRM dominam politicamente a arena nacional. O segundo ciclo, compreendido de 1945 a 1964, foram analisados os processos eleitorais estaduais e nacionais. Nestes, os resultados analíticos mostram o que refletem no comportamento político-partidário dos partidos do passado e do presente no país. Outro aspecto importante também abordado na primeira parte foi a verticalização das alianças eleitorais, a qual teve como objetivo impor harmonia partidária entre os partidos nas formações das alianças eleitorais. Revendo esse processo político, vimos que, a imposição da verticalização não resolveu o problema da inexistência harmônica dos partidos no ato da formação das alianças eleitorais tocante ao espectro ideológico. A segunda parte da pesquisa está dividida em duas partes. A primeira faz uma análise sobre a trajetória política do PT e suas políticas de alianças, que se inicia no V Encontro Nacional do Partido em 1987. Como consequência da expansão partidária, outras políticas de alianças são aprovadas pelo Partido dos Trabalhadores. Na segunda parte, é trabalhada as eleições municipais de 2008 em Natal, que observa analiticamente a campanha do PT e as alianças eleitorais realizadas pelo Partido para participar do pleito. Os velhos adversários políticos e oligárquicos formaram alianças com PT. Partido que nasceu combatendo as velhas práticas da política conservadora no nosso país, nos estados e nos municípios brasileiros

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This research had as purpose to establish the logic symbolic present in the contemporary society that facilitated the emergency of a public speech on the incest, and, consequently, to demonstrate the ideological nature that structures it. Event associated to the order of the taboo, the incest would be the transgression of the injunction that, second Lévi-Strauss, facilitated the emergency of the Culture while symbolic order, differentiated of the natural order. The injunction of the incest would reveal the elementary and universal structures of the order symbolic presents in the human societies: the demand of the Rule as rule; the reciprocity and the gift, present element in the social changes that it transforms the individuals in partners, increasing a new quality in the transferred value, according to Lévi-Strauss. Starting from this, I developed the hypothesis second which the phenomenon of the alone incest became an event of discursive order and public as right social transformations affected the normative system (social representations, values, moral) regulator of the relationships among the social subjects, being reflected like this, in the own structuring of the Law. A second work hypothesis was developed starting from that. I develop it leaving of the argument that if when inserting the discussion of the thematic of the defense of the children and adolescent rights, being then, considering it while "privileged modality of sexual abuse against children", the present central subjects in the structuring of the social entail would be leaved. Being like this, the partner-institutional speech on the incest would answer the social demands of order and social control, becoming like this, discursive formations of ideological character. This research work tried to follow the hypothesis above referred, demonstrating the singular sense that it will be attributed to the incest in the contemporary society, particularly, its relationship with the Law and the transgression in the contemporary society

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As one of the most important cities in the state of Pernambuco, Petrolina is settled in the Pernabucanian backwoods, a place that still holds its own traditions and manners. Petrolina s economy is mainly based on primary activities. It s politics is run by Family groups which preserve themselves and remain in power, using the clientelism, which could be said as a give and get practice. That means that the suffrage is a currency to exchange benefits. The present study analyses facts occurred in the political history of the Coelho s Family, which still dominates the local Politics. They persist as heirs of the old system of Coronelism that is maintaining their power structuring a political machine, which is able to make them unbeatable for over fifty years. Despite of a family internal division, it benefits all of them, directly or indirectly. Based on empirical observation, we set a brief historical of the Coelho s family facts, in order to demonstrate the range of their power through the ancestry, which is to say we ve described the local political labyrinths. Our metodological choices were driven by the comprehensive sociology, through the Weberian ideal types, in order to find the answers for the historical, social and political conformation of the facts, in consonance with the reality. According to that, we ve studied the Coelho s political trajectory from 1968 to 2012, considering the election periods. Commonplace: where a new generation becomes active subjects on a new apprenticeship, moral and intellectual. After all, they are all family heirs

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Water production is unavoidable during a petrol well s lifetime. The amount of produced water associated with oil varies a lot. It can reach values which account to 50% in volume up to nearly 100%, at the end of the well s economic life. It could be verified that, once the water reaches the productive wells, there must be a management of this produced water. Its destiny is defined after a precise study, after which the best option is chosen between relieving it into the environment, re-injecting it into the producing container or disposing it into non-producing formations. Whichever option is made by the involved professionals, after the necessary analysis, it shall consider, besides the technical and economical aspects, also the alternatives which entail less environmental impact. The purpose of the present research is to conduct a study about the application of the constitutional principle of efficiency on the instruments worked out by the public administration on water management, specifically the water use licence and charging for the use in the management of water resources applicable to water production at the petrol wells. In this attempt, before entering the proper approach of the efficiency of the mentioned instruments, it was necessary not only bring to light the doctrinal perception about the constitutional principle of administrative efficiency, but also make some considerations concerning to the structure of the national water resources management, set by the Federal Constitution (1988) and the federal legislation (9433/97)