Estudo paramétrico da recuperação de óleo no processo de drenagem gravitacional com injeção de CO2

The gas injection has become the most important IOR process in the United States. Furthermore, the year 2006 marks the first time the gas injection IOR production has surpassed that of steam injection. In Brazil, the installation of a petrochemical complex in the Northeast of Brazil (Bahia State) offers opportunities for the injection of gases in the fields located in the Recôncavo Basin. Field-scale gas injection applications have almost always been associated with design and operational difficulties. The mobility ratio, which controls the volumetric sweep, between the injected gas and displaced oil bank in gas processes, is typically unfavorable due to the relatively low viscosity of the injected gas. Furthermore, the difference between their densities results in severe gravity segregation of fluids in the reservoirs, consequently leading to poor control in the volumetric sweep. Nowadays, from the above applications of gas injection, the WAG process is most popular. However, in attempting to solve the mobility problems, the WAG process gives rise to other problems associated with increased water saturation in the reservoir including diminished gas injectivity and increased competition to the flow of oil. The low field performance of WAG floods with oil recoveries in the range of 5-10% is a clear indication of these problems. In order to find na effective alternative to WAG, the Gas Assisted Gravity Drainage (GAGD) was developed. This process is designed to take advantage of gravity force to allow vertical segregation between the injected CO2 and reservoir crude oil due to their density difference. This process consists of placing horizontal producers near the bottom of the pay zone and injecting gás through existing vertical wells in field. Homogeneous models were used in this work which can be extrapolated to commercial application for fields located in the Northeast of Brazil. The simulations were performed in a CMG simulator, the STARS 2007.11, where some parameters and their interactions were analyzed. The results have shown that the CO2 injection in GAGD process increased significantly the rate and the final recovery of oil

Estudo da segregação gravitacional do processo de injeção de vapor em reservátórios heterogêneos

Due to reservoirs complexity and significantly large reserves, heavy oil recovery has become one of the major oil industry challenges. Thus, thermal methods have been widely used as a strategic method to improve heavy oil recovery. These methods improve oil displacement through viscosity reduction, enabling oil production in fields which are not considered commercial by conventional recovery methods. Among the thermal processes, steam flooding is the most used today. One consequence in this process is gravity segregation, given by difference between reservoir and injected fluids density. This phenomenon may be influenced by the presence of reservoir heterogeneities. Since most of the studies are carried out in homogeneous reservoirs, more detailed studies of heterogeneities effects in the reservoirs during steam flooding are necessary, since most oil reservoirs are heterogeneous. This paper presents a study of reservoir heterogeneities and their influence in gravity segregation during steam flooding process. In this study some heterogeneous reservoirs with physical characteristics similar those found in the Brazilian Northeast Basin were analyzed. To carry out the simulations, it was used the commercial simulator STARS by CMG (Computer Modeling Group) - version 2007.11. Heterogeneities were modeled with lower permeability layers. Results showed that the presence of low permeability barriers can improve the oil recovery, and reduce the effects of gravity segregation, depending on the location of heterogeneities. The presence of these barriers have also increased the recovered fraction even with the reduction of injected steam rate

Análise paramétrica da simulação composicional do processo de Drenagem Gravitacional Assistida por Gás (GAGD)

In Brazil and around the world, oil companies are looking for, and expected development of new technologies and processes that can increase the oil recovery factor in mature reservoirs, in a simple and inexpensive way. So, the latest research has developed a new process called Gas Assisted Gravity Drainage (GAGD) which was classified as a gas injection IOR. The process, which is undergoing pilot testing in the field, is being extensively studied through physical scale models and core-floods laboratory, due to high oil recoveries in relation to other gas injection IOR. This process consists of injecting gas at the top of a reservoir through horizontal or vertical injector wells and displacing the oil, taking advantage of natural gravity segregation of fluids, to a horizontal producer well placed at the bottom of the reservoir. To study this process it was modeled a homogeneous reservoir and a model of multi-component fluid with characteristics similar to light oil Brazilian fields through a compositional simulator, to optimize the operational parameters. The model of the process was simulated in GEM (CMG, 2009.10). The operational parameters studied were the gas injection rate, the type of gas injection, the location of the injector and production well. We also studied the presence of water drive in the process. The results showed that the maximum vertical spacing between the two wells, caused the maximum recovery of oil in GAGD. Also, it was found that the largest flow injection, it obtained the largest recovery factors. This parameter controls the speed of the front of the gas injected and determined if the gravitational force dominates or not the process in the recovery of oil. Natural gas had better performance than CO2 and that the presence of aquifer in the reservoir was less influential in the process. In economic analysis found that by injecting natural gas is obtained more economically beneficial than CO2

Estudo da perda de carga e calor no poço injetor no processo De drenagem gravitacional assistida por vapor (SAGD)

The oil companies in the area in general are looking for new technologies that can increase the recovery factor of oil contained in reservoirs. These investments are mainly aimed at reducing the costs of projects which are high. Steam injection is one of these special methods of recovery in which steam is injected into the reservoir in order to reduce the viscosity of the oil and make it more mobile. The process assisted gravity drainage steam (SAGD) using steam injection in its mechanism, as well as two parallel horizontal wells. In this process steam is injected through the horizontal injection well, then a vapor chamber is formed by heating the oil in the reservoir and, by the action of gravitational forces, this oil is drained down to where the production well. This study aims to analyze the influence of pressure drop and heat along the injection well in the SAGD process. Numerical simulations were performed using the thermal simulator STARS of CMG (Computer Modeling Group). The parameters studied were the thermal conductivity of the formation, the flow of steam injection, the inner diameter of the column, the steam quality and temperature. A factorial design was used to verify the influence of the parameters studied in the recovery factor. We also analyzed different injection flow rates for the model with pressure drop and no pressure drop, as well as different maximum flow rates of oil production. Finally, we performed an economic analysis of the two models in order to check the profitability of the projects studied. The results showed that the pressure drop in injection well have a significant influence on the SAGD process.

Estudo do processo de drenagem gravitacional do óleo assistido com injeção de vapor e solvente

Como os recursos de hidrocarbonetos convencionais estão se esgotando, a crescente demanda mundial por energia impulsiona a indústria do petróleo para desenvolver mais reservatórios não convencionais. Os recursos mundiais de betume e óleo pesado são estimados em 5,6 trilhões de barris, dos quais 80% estão localizados na Venezuela, Canadá e EUA. Um dos métodos para explorar estes hidrocarbonetos é o processo de drenagem gravitacional assistido com injeção de vapor e solvente (ES-SAGD Expanding Solvent Steam Assisted Gravity Drainage). Neste processo são utilizados dois poços horizontais paralelos e situados verticalmente um acima do outro, um produtor na base do reservatório e um injetor de vapor e solvente no topo do reservatório. Este processo é composto por um método térmico (injeção de vapor) e um método miscível (injeção de solvente) com a finalidade de causar a redução das tensões interfaciais e da viscosidade do óleo ou betume. O objetivo deste estudo é analisar a sensibilidade de alguns parâmetros operacionais, tais como: tipo de solvente injetado, qualidade do vapor, distância vertical entre os poços, porcentagem de solvente injetado e vazão de injeção de vapor sobre o fator de recuperação para 5, 10 e 15 anos. Os estudos foram realizados através de simulações concretizadas no módulo STARS (Steam Thermal, and Advanced Processes Reservoir Simulator) do programa da CMG (Computer Modelling Group), versão 2010.10, onde as interações entre os parâmetros operacionais, estudados em um modelo homogêneo com características de reservatórios semelhantes aos encontrados no Nordeste Brasileiro, foram observadas. Os resultados obtidos neste estudo mostraram que os melhores fatores de recuperação ocorreram para níveis máximos do percentual de solvente injetado e da distância vertical entre os poços. Observou-se também que o processo será rentável dependendo do tipo e do valor do solvente injetado

Efeito da perda de carga e calor no poço injetor no processo de drenagem gravitacional assistido com vapor e solvente

Nowadays, most of the hydrocarbon reserves in the world are in the form of heavy oil, ultra - heavy or bitumen. For the extraction and production of this resource is required to implement new technologies. One of the promising processes for the recovery of this oil is the Expanding Solvent Steam Assisted Gravity Drainage (ES-SAGD) which uses two parallel horizontal wells, where the injection well is situated vertically above the production well. The completion of the process occurs upon injection of a hydrocarbon additive at low concentration in conjunction with steam. The steam adds heat to reduce the viscosity of the oil and solvent aids in reducing the interfacial tension between oil/ solvent. The main force acting in this process is the gravitational and the heat transfer takes place by conduction, convection and latent heat of steam. In this study was used the discretized wellbore model, where the well is discretized in the same way that the reservoir and each section of the well treated as a block of grid, with interblock connection with the reservoir. This study aims to analyze the influence of the pressure drop and heat along the injection well in the ES-SAGD process. The model used for the study is a homogeneous reservoir, semi synthetic with characteristics of the Brazilian Northeast and numerical simulations were performed using the STARS thermal simulator from CMG (Computer Modelling Group). The operational parameters analyzed were: percentage of solvent injected, the flow of steam injection, vertical distance between the wells and steam quality. All of them were significant in oil recovery factor positively influencing this. The results showed that, for all cases analyzed, the model considers the pressure drop has cumulative production of oil below its respective model that disregards such loss. This difference is more pronounced the lower the value of the flow of steam injection

Luz e sombra: uma interpretação de suas significações imaginárias nas imagens do cinema expressionista alemão e do cinema noir americano

The present investigation proposes an approach of light and shadow and their imaginary significations in the images of both German expressionist movie and the American noir movie, whose aesthetic experience is expressed through a contrasting bright/dark photography, loaded with symbolism. The interpretation of the imaginary significations of this imagistic material is based on Gilbert Durand´s imaginary anthropological theories that deal with a myriad of symbols gathered according to their semantic isomorphism and linked to more general structures named as Daily and nightly Image Regime . There come to gravitate, around such regimes, symbols attached to division and purification, ascensional and spectacular, with imaginary significations homological to Light and Good, and symbols associated to night, fall and animalism, isomorphic of Shadow and Evil

O Insituto do Amicus Curiae no controle de consitucionalide brasileiro: uma abordagem à luz da efetividade do princípio do acesso à justiça

It presents a study about the control of constitutionality, its requirements and beddings. It brings, at first, notions about the concept of constitution, in its most varied aspects, as well as the systems of Control of Constitutionality. It emphasizes, considering the actual Brazilian situation, which passes through constitutional reforms and, therefore, assenting the appearance of an enormous amount of ordinary laws, the legal instability that has formed itself within the national panoram. Because of this situation, the institute of the Control of Constitutionality gains inmportancy as a way of protection of our Great Letter, against possible violations which can unfortunately happen. More ahead in the difuse control of constitutionality argues the new trend of generalization, especially after the recent reform that introduced the general repercussion as new requirement of admissibilidade of the appeal to the Brazilian Supreme Court. In the final chapter brings an analysis on the institute of amicus curiae, arguing its historical origins and its evolution, in the comparative jurisprudence, and the Brazilian right. From then is gone deep the paper of amicus curiae in the constitutionality control and, after quarrel on the difficulties of the Brazilian population to materialize its right before the judiciary, as this new institute could contribute in basic way for the materialization of the constitutional rule of access to justice

Licenciamento ambiental em postos de revenda de combustíveis à luz dos princípios constitucionais de defesas do meio ambiente: o caso do município de Natal/RN

This study approaches the question of the administrative procedure of the environmental licensing of ranks of fuel resale, taking as basis a study case of the reality of the City of Natal/RN (Brazil). For in such a way, it was done a retrospect on the evolution of the system of road transport in Brazil, having started to briefly analyze the urbanization process that if after accented in the capitals of the Brazilian States the decade of 1950, relating these subjects with the growth of the sector of fuel resale. After that, it was transferred boarding of the defense of the national environment to the light of ambient principles constitutional. In the sequence, a boarding on the ambient guardianship in the Federal Constitution of 1988 was made, treating basically specifies and on the national urban politics and the national politics of the environment, with its instruments. In the sequence, it was transferred the analysis of the abilities and attributions of the National Advice of the Environment (CONAMA) and its Resolutions, for then only enter in the most important part of this work: an analysis of the environmental licensing of ranks of fuel resale, in the reality of the City of Natal/RN. Before this specific boarding, it was proceeded specifically a survey and communication from the applicable norms to such establishments (Resolutions of the CONAMA and norms of the ABNT), for after that carrying through an geo-ambient characterization of the City of Natal/RN. Finally, a reflection was made on the possibility of magnifying of the state activity, in terms of guarantees for the responsible members for the environmental policy and of administrative efficiency, through the idea of the ambient regulation. For the accomplishment of this study, it was proceeded research in diverse sources such as books, magazines, sites of the Internet, periodicals, thesis and dissertations, among others material, beyond visits the agencies that direct or indirectly act with the ambient defense and as fuel resale, such as Secretariat of Environment and Urbanism of the City of Natal (SEMURB), Institute of Economic Development and Environment of RN (IDEMA), Brazilian Institute of the Environment and the Natural resources You renewed, Executive Management of RN (IBAMA/RN), Public prosecutor's office of the Environment of Natal (Public prosecution service of the RN), National Agency of Oil (ANP) and Union of the Retailing of Derivatives of Oil of the RN, among others. To the end, satiated regulation is observed that although on the substance of the ambient licensing in ranks of fuel resale, also with federal, state and municipal norms, the municipal Public Power is very far from the fulfilment of its institutional functions, in the question environmental policy of these establishments, a time that few are the permitted ranks of resale in the city of Natal/RN

A Constitucionalidade do decreto de licitações da Petrobrás à luz dos princípios da legalidade e da eficiência

PETROBRAS, a Brazilian oil company, follows principles of public administration and from the Constitutional Amendment 9/95 in Brazil began to compete with other companies with the flexibility of the oil monopoly. In this new model started to use the simplified procedure for bidding so that could compete on equal terms. The ordinance that adopted a simplified procedure for bidding has been the subject of some criticism and lawsuits especially under the Court of Audit and the Supreme Court in Brazil. The analysis of their constitutionality, and the possibility of their use by other group companies is the theme of this work, and for this purpose, permeates through the notions of judicial review in the Brazilian law on the stage of law and economics analysis of the norm, and the principles applicable to PETROBRAS and the devices most frequently asked about the implementation of 2745/98 Decree. For this, the basic issue that should be investigated further is the regulatory power of the Federal Executive and the delegation of powers within the legislature and its conformation to the constitutional regency

O dumping ambiental no setor sucroalcooleiro à luz do princípio da livre concorrência

The goal of this study is to investigate about the existence or absence of environmental dumping in the production of fuel ethanol in Brazil, as well as identifying the reasons why the figure of ecological dumping is pernicious to the principles enumerated in constitutional economic order, in particular the principle of free competition. In the twenty-first century environmental issues gained momentum and importance in these terms, which was seen as a mere fallacy given the concern of governments of various countries, after all, environmental protection shows up as the only means of bringing about the maintenance of life at planet. Indeed, it is essential to halt the drastic effects of climate change, and think fast and efficient solutions. Undoubtedly, the contemporary requirements that resulted in the transition to a new economy brings with it the duty of enterprise search for sustainability, and this behavior can not be passive, otherwise it is imperative to work hard and incessant economic agents, even if initially costs are high, this step will ensure a production accountable, transparent and free from accusations of environmental degradation. It is also intended to study the importance of the sector not only as a source of economic growth, but mainly, its contribution to national development, without forgetting that this is devoted in the Constitution of 1988 as one of the objectives of the Federative Republic of Brazil. In fact, the criticism most common perceptions about the production of biofuels, said the interests of the countries producing them in large scale, will eventually generate a exhaustion of soil and a significant increase in food prices. However, the ethanol produced in Brazil is unique in that it is produced from cane sugar, a product is not intended for human or animal, not to mention that the recovery of land just to the rotation with the planting other cultures. It is expected that environmental certifications are useful to demonstrate the quality of ethanol for export and to refute unfounded criticism. Finally, this study will be analyzed further solutions for the plants to develop an economic activity without damaging the environment and in compliance with Brazilian law

A questão do petróleo em terras indígenas: uma análise constitucional à luz do desenvolvimento sustentável

Recognizing the need to preserve a national ethnic minority, the Constitution, inspired by the pluralistic values of the Constitutional Law State, stipulated a series of rights and guarantees for the conservation of indigenous cultural singularity, disciplining in article 231 the Indians right to maintain their social organization, customs, languages, beliefs and traditions, as well as safeguarding the rights to the lands they traditionally occupy, and the exclusive use of the wealth existing in them, premise of ensuring their physical and cultural continuity, breaking decisively with the paradigm the assimilation of the Indian national civilization. However, despite the Indian policy of ethnic and cultural preservation, the Constitution allowed the exploitation of minerals in aboriginal territory, incorporated herein hydrocarbons, provided they meet certain predetermined requirements, leaving it to the legislature the discipline of ordinary matter. However, this law has not yet been published, with some projects in the National Congress, leaving thus precluding the indigenous subsurface oil exploration until the enactment of enabling legislation. Meanwhile, this paper carries out an integrated analysis of the constitutional protection of ethnic and cultural uniqueness of indigenous peoples, Convention Nº 169 of the International Labour Organization and the bill presented by Deputy Eduardo Valverde, in an attempt to consolidate sustainable development practices in the sector, through developing a system of social and environmental responsible oil exploration, aligning with national energy needs to maintain a balanced environment and preservation of socio-cultural organization of a minority so weakened and beaten over five centuries of domination

Da jurisdição constitucional: uma análise da concretização dos direitos fundamentais à luz da hermenêutica constitucional

Trabalho sobre a concretização dos direitos fundamentais pela jurisdição constitucional, mostrando a importância da interpretação da Constituição para a obtenção da eficácia de tais direitos. Desenvolve-se a pesquisa a partir da explicação histórica sobre o constitucionalismo moderno, que implantou o Estado Liberal de Direito e as constituições escritas, e no qual encontra a jurisdição constitucional o seu embasamento cultural e a sua justificação histórica. Verifica-se que a origem da jurisdição constitucional assenta-se no controle da constitucionalidade das leis e atos normativos do poder público, fundado no princípio da supremacia da Constituição. Destaca-se o realce dado pela teoria material da Constituição à normatividade dos princípios constitucionais, tecendo considerações em torno da classificação das normas constitucionais em regras e princípios. Remarca o trabalho que o controle da constitucionalidade pode ser formal ou material, apresentando esta última modalidade uma conotação acentuadamente política, já que, por ele, a aferição da compatibilidade da norma infraconstitucional é feita com o conteúdo material da Constituição. A função primacial da jurisdição constitucional é tutelar os direitos fundamentais, especialmente os das minorias sociais. Tal função sobreleva-se até mesmo contra textos legislativos produzidos por maiorias eventuais, pois o princípio da supremacia da Constituição prevalece sobre a regra da maioria vigente nos regimes democráticos. Comprova-se que a concepção substancialista, adotada para definir os contornos funcionais da jurisdição constitucional, propõe uma maior intervenção desta na apreciação dos casos que lhe são submetidos. Salienta-se que, no Estado Democrático de Direito, derivado da aglutinação do Estado Liberal com o Estado Social e acrescida de um elemento novo voltado à transformação da realidade social, a jurisdição constitucional passa a levar em conta, com mais atenção e destaque, os princípios constitucionais e a sincronia do ordenamento constitucional com a sociedade por ele ordenada. Realça também o estudo que a atuação da jurisdição constitucional, segundo a ideologia democrática defendida pelo Estado Democrático de Direito, tem logrado obter uma sociedade mais justa, e que a comprovação histórica é francamente favorável ao seu ativismo judicial. Os direitos fundamentais dificilmente se dissociam da democracia, que lhes garante a eficácia pela limitação e visibilidade do exercício do poder, traços políticos que constituem a nota típica dos regimes democráticos. Mesmo que os direitos fundamentais tenham tido um caráter pré-estatal como preconizado pelo jusnaturalismo, são eles normas, e não valores, pois tão logo sejam positivados pela Constituição eles se tornam direitos vigentes. Assevera a pesquisa que os métodos concretistas de interpretação constitucional mostram-se mais adequados à obtenção da eficácia da Constituição, pela importância que os elementos objetivos, relacionados com o contexto material da norma, assumem no seu processo de aplicação e interpretação. Conclui-se ser essencial que os operadores e estudiosos do Direito se conscientizem de que a interpretação constitucional deve assumir uma feição principiológica e concretista, de modo a ser obtida a máxima eficácia possível das normas constitucionais, especialmente as de direitos fundamentais, acentuando-se mais a necessidade de um Tribunal Constitucional, cuja criação no Brasil constitui ainda tema polêmico entre os doutrinadores

Biomassa e desenvolvimento sustentável e sócio regional no Brasil: uma análise à luz da Constituição Federal de 1988

It is verified worldwide an increasing concern with the protection of natural resources in the planet, a fact that became relevant in Brazil since the promulgation of the Constitution of 1988, based on the viewpoint of sustainable development, which seeks to promote economic activities in the country according to the need for conservation and preservation of natural resources for the use of present and future generations. In addition, we seek to reduce the differences that occur in our society by determining as a fundamental objective to be persecuted by the Federative Republic of Brazil the reduction of social and regional inequalities. A value that should also be observed in the context of economic activities developed here, since it is a general principle of financial and economic order of the country. Therefore, considering the exhaustion of world s reserves of fossil fuels, as well as the impacts on the environment, especially for the large emission of greenhouse effect gases, the debate about the need to change the global energy matrix increases while alternative energy sources appears as a bet to fulfill the contemporary aspirations for sustainability, and Brazil emerges in a very favorable position, because it has the essential natural conditions to allow this sector s full development. In this perspective, the work has the scope to analyze how the production of alternative energy sources may act in the search for concretization of constitutional values, to promote sustainable development for present and future generations, and to reduce regional and social inequalities in an attempt to improve the quality of life of the population. It will also be observed the current regulatory framework of alternative energy sources in the national laws to verify the existence of legal and institutional security, which is necessary to guarantee the full development of the sector in the country. And to investigate the expected results, it will be observed through the concrete evaluation of specific practices adopted in the industry, analyzing their actual compliance with the constitutional provisions under analysis, based on the examination of the possibility of using renewable biomass sources for biofuel production, promoting development to the country, indicating the opening lines about how this important sector can act to solve the energy challenge today

Nacionalização do trabalho e constituição: análise das regras de nacionalização do trabalho à luz do princípio da isonomia

There is a clear relationship between citizenship and labor market. While foreign nationals are equal in dignity and rights in the laws governing the employment of this labor force. Motivated by reasons of state security or political direction, such laws to a greater or lesser degree, create establish a system of worker protection in the face of the foreign national. These rules have a direct impact on economic regulation, as they can affect the supply of skilled labor or not, articulating with the economic order envisaged by the 1988 Constitution. The Constitution adopts several principles in its economic order, so that the issues involving the rules of the nationalization of all work must be considered in a systematic way, one can not choose a pleasure interpreter. The nationalization of the work rules are not unique to Brazil, similar rules exist in several countries of South America and Africa. In Europe they already existed, but lost out on the basis of treaties setting up the European Union, although other mechanisms are used for the purpose of protecting the citizens of the member states, making policies equal treatment legislation symbolic. The nationalization of the work rules governing the relationship between nationality and the labor market and are in a legal category, which has a function to fulfill in the Brazilian legal system. Not all rules nationalization violate the principle of equality, as it is possible, depending on the circumstance indeed adopt a criterion that implies differentiation between nationals and foreigners. The Constitution has a will arising from its normative force, so that the assumptions it (constitution) used to discriminate may also be possible by ordinary legislation, since the situation is actually justifiably constitutional