Influência das tensões tectônicas na permeabilidade da formação Açu - Bacia Potiguar

The behavior of the fluid flux in oil fields is influenced by different factors and it has a big impact on the recovery of hydrocarbons. There is a need of evaluating and adapting the actual technology to the worldwide reservoirs reality, not only on the exploration (reservoir discovers) but also on the development of those that were already discovered, however not yet produced. The in situ combustion (ISC) is a suitable technique for these recovery of hydrocarbons, although it remains complex to be implemented. The main objective of this research was to study the application of the ISC as an advanced oil recovery technique through a parametric analysis of the process using vertical wells within a semi synthetic reservoir that had the characteristics from the brazilian northwest, in order to determine which of those parameters could influence the process, verifying the technical and economical viability of the method on the oil industry. For that analysis, a commercial reservoir simulation program for thermal processes was used, called steam thermal and advanced processes reservoir simulator (STARS) from the computer modeling group (CMG). This study aims, through the numerical analysis, find results that help improve mainly the interpretation and comprehension of the main problems related to the ISC method, which are not yet dominated. From the results obtained, it was proved that the mediation promoted by the thermal process ISC over the oil recovery is very important, with rates and cumulated production positively influenced by the method application. It was seen that the application of the method improves the oil mobility as a function of the heating when the combustion front forms inside the reservoir. Among all the analyzed parameters, the activation energy presented the bigger influence, it means, the lower the activation energy the bigger the fraction of recovered oil, as a function of the chemical reactions speed rise. It was also verified that the higher the enthalpy of the reaction, the bigger the fraction of recovered oil, due to a bigger amount of released energy inside the system, helping the ISC. The reservoir parameters: porosity and permeability showed to have lower influence on the ISC. Among the operational parameters that were analyzed, the injection rate was the one that showed a stronger influence on the ISC method, because, the higher the value of the injection rate, the higher was the result obtained, mainly due to maintaining the combustion front. In connection with the oxygen concentration, an increase of the percentage of this parameter translates into a higher fraction of recovered oil, because the quantity of fuel, helping the advance and the maintenance of the combustion front for a longer period of time. About the economic analysis, the ISC method showed to be economically feasible when evaluated through the net present value (NPV), considering the injection rates: the higher the injection rate, the higher the financial incomes of the final project

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 combustão in-situ em reservatórios maduros de óleos médios e leves (high pressure air injection)

Nearly 3 x 1011 m3 of medium and light oils will remain in reservoirs worldwide after conventional recovery methods have been exhausted and much of this volume would be recovered by Enhanced Oil Recovery (EOR) methods. The in-situ combustion (ISC) is an EOR method in which an oxygen-containing gas is injected into a reservoir where it reacts with the crude oil to create a high-temperature combustion front that is propagated through the reservoir. The High Pressure Air Injection (HPAI) method is a particular denomination of the air injection process applied in light oil reservoirs, for which the combustion reactions are dominant between 150 and 300°C and the generation of flue gas is the main factor to the oil displacement. A simulation model of a homogeneous reservoir was built to study, which was initially undergone to primary production, for 3 years, next by a waterflooding process for 21 more years. At this point, with the mature condition established into the reservoir, three variations of this model were selected, according to the recovery factors (RF) reached, for study the in-situ combustion (HPAI) technique. Next to this, a sensitivity analysis on the RF of characteristic operational parameters of the method was carried out: air injection rate per well, oxygen concentration into the injected gas, patterns of air injection and wells perforations configuration. This analysis, for 10 more years of production time, was performed with assistance of the central composite design. The reservoir behavior and the impacts of chemical reactions parameters and of reservoir particularities on the RF were also evaluated. An economic analysis and a study to maximize the RF of the process were also carried out. The simulation runs were performed in the simulator of thermal processes in reservoirs STARS (Steam, Thermal, and Advanced Processes Reservoir Simulator) from CMG (Computer Modelling Group). The results showed the incremental RF were small and the net present value (NPV) is affected by high initial investments to compress the air. It was noticed that the adoption of high oxygen concentration into the injected gas and of the five spot pattern tends to improve the RF, and the wells perforations configuration has more influence with the increase of the oil thickness. Simulated cases relating to the reservoir particularities showed that smaller residual oil saturations to gas lead to greater RF and the presence of heterogeneities results in important variations on the RF and on the production curves

Custos e rentabilidade da produção de juvenis de tilápia-do-nilo em tanques-rede utilizando-se diferentes densidades de estocagem

Neste trabalho foi realizada a análise econômica da produção de juvenis de tilápia-do-nilo em tanques-rede utilizando-se diferentes densidades de estocagem. O experimento foi desenvolvido em área aquícola, em delineamento de blocos casualizados, com quatro densidades de estocagem (100, 200, 300 e 400 peixes m-3), avaliadas com seis repetições, em dois períodos de criação: de março a abril de 2005 (52 dias - peso inicial de 43,08 ± 2,98 g e peso final de 262,14 ± 47,86 g) e de março a abril de 2006 (58 dias - peso inicial de 43,16 ± 5,34 g e peso final 314,24 ± 73,30 g). Foram avaliadas as seguintes variáveis econômicas: custo da ração mais custo do juvenil dividido pela biomassa, em R$ kg-1; porcentagem do custo da ração por quilo de peixe produzido sobre o preço de venda; porcentagem do custo do juvenil por quilo de peixe produzido sobre o preço de venda e; porcentagem dos custos da ração mais do juvenil por quilo de peixe produzido sobre o preço de venda. da menor densidade de estocagem (100) para a maior (400), ocorreu diminuição no ganho de peso diário e elevação do índice de conversão alimentar aparente, mas essa redução não comprometeu a taxa de sobrevivência. Entretanto, o ganho de biomassa aumentou com o adensamento de peixes. As maiores receitas líquidas foram obtidas nas densidades de estocagem de 100 e 200 peixes m-3. Os preços não remuneraram os custos operacionais (efetivo e total) em maiores densidades (300 e 400 peixes m-3). Os melhores resultados para a produção de juvenis de tilápia-do-nilo foram obtidos com densidades de até 200 peixes m-3.

O princípio constitucional da redução das desigualdades regionais e o transporte de gás natural

In a country of continental dimensions as Brazil, one of the top challenges to its economic growth is the logistic related to energetical demand supply. We live now in the era of environmental protection and, in this new context of priorizations, it passes trough the search for alternative energies for the energetic matrix, due the petroleum elevated costs in the global market (and its finitude), but also due its pollution over the environment. This attempt of substitution needs solutions related to the national reality, into a national long term developing plan and based at a juridical-economic analysis of its realization. This study will look for, also based in an economical analysis, the juridical legitimity of choosing natural gas as the new protagonist of national economic growth (as a substitute of petroleum) and the necessary boost that must be done by law, based on an economic policy focused strictly for that fact, as a modifying agent of this reality. This study, therefore, will always be turned to a constitutional aspect, respecting the principles of economic order and the goal of reducing regional inequalities, which must influence the making off of a developing plan. At the end, it will try to demonstrate the juridical viability of such undertaking, tuned in jus-economical criteria. Another goal is related to the analysis of the natural gas industry, due the regulation of its transport has a major importance for national energetic integration, not only because this activity be characterized as a net industry, still under control of a natural monopoly, but also because the competitive or cooperative profile that should be priorized at the beginning of the economic planning for this activity (such as investment policies and its own rules that will submit private agents)

Análise econômica da expansão do direito penal

Aborda a evolução histórica das liberdades individuais, a partir de apontamentos pertinentes ao constitucionalismo liberal, à formação do Estado de Direito e ao advento dos regimes democráticos amparados em direitos fundamentais. Pretende, quanto aos direitos fundamentais, mostrar diversas classificações, funções, critérios e conceitos, além da sistematização de gerações ou dimensões de direitos. Discorre acerca da teoria dos limites aos limites, ao lado de teorias correlatas em profícua confrontação doutrinária, tudo com fins a estruturar os conceitos basilares de direitos de liberdade, que orientam o restante da obra. Trata do cenário histórico-jurídico do surgimento da Análise Econômica do Direito (AED), consistente, sobretudo, no jusrealismo norte-americano, abordado, em paralelo, com o realismo jurídico escandinavo. Aplica conceitos e premissas de microeconomia ao Direito Penal, com ênfase para a investigação do comportamento criminoso empreendida pela Economia do Crime. Avança não apenas restrito à perspectiva teórica, trazendo dados empíricos e implicações concretas da teoria econômica dos delitos e das penas, que serão reconhecidos na evolução e redução da criminalidade, nas políticas de desarmamento, na estruturação empresarial do narcotráfico, bem como na otimização da administração penitenciária brasileira a fim de concretizar o preconizado pela legislação de execução penal. Desenvolve estudo a partir da leitura histórica do Direito Penal, passando pelos conceitos de sociedade complexa e de riscos. Analisa, após fixados tais pressupostos, algumas causas do processo de expansão do Direito Penal com vistas a identificar propostas alternativas ao hiperpunitivismo hodierno, preservando-se, assim, os direitos de liberdade que sustentam o Estado Democrático de Direito. Propõe uma desconstrução do conceito jurídico do princípio da eficiência administrativa, demonstrando como seu conteúdo normativo foi demasiadamente mitigado pela recepção precária dos respectivos elementos econômicos por parte da doutrina e da jurisprudência pátria. Ressalta a importância jurídica da eficiência econômica, devidamente harmonizada com os demais princípios constitucionais, por força do instrumental analítico da AED Positiva. Investiga criticamente algumas teorias sociológicas tendentes ao funcionalismo penal, sob referenciais de eficiência e de direitos de liberdade. Almeja, ao final, propor a AED como alternativa à expansão funcionalista e irracional dos tipos e sanções criminais, de modo que a aproximação entre Economia do Crime, eficiência econômica e Direito Penal contribua para blindar os direitos de liberdade das vicissitudes típicas da sociedade contemporânea

Tributação, finanças públicas e política fiscal: uma análise sob a óptica do direito e economia

In the Brazilian legal scenario, the study of taxation has traditionally been restricted to positivist analysis, concerned with investigating the formal aspects of the tax legal rule. Despite its relevance to the formation of the national doctrine of tax, such formalist tradition limits the discipline, separating it from reality and the socioeconomic context in which the Tax Law is inserted. Thus, the proposal of the dissertation is to examine the fundamentals and nature of taxation and tax legal rules from the perspective of Law and Economics (Economic Analysis of Law). For this purpose, the work initially reconnects the Tax Law and Science of Finance (or Public Finance) and Fiscal Policy, undertaking not only a legal analysis, but also economic and financial analysis of the theme. The Economics of Public Sector (or Modern Public Finance) will contribute to the research through topics such as market failures and economic theory of taxation, which are essential to an economic approach to Tax Law. The core of the work lies in the application of Law and Economics instruments in the study of taxation, analyzing the effects of tax rules on the economic system. Accordingly, the dissertation examines the fundamental assumptions that make up the Economic Analysis of Law (as the concept of economic efficiency and its relation to equity), relating them to the tax phenomenon. Due to the nature of the Brazilian legal system, any worth investigation or approach, including Law and Economics, could not pass off the Constitution. Thus, the constitutional rules will serve as a limit and a prerequisite for the application of Law and Economics on taxation, particularly the rules related to property rights, freedom, equality and legal certainty. The relationship between taxation and market failures receives prominent role, particularly due to its importance to the Law and Economics, as well as to the role that taxation plays in the correction of these failures. In addition to performing a review of taxation under the approach of Economic Analysis of Law, the research also investigates the reality of Brazilian tax system, applying the concepts developed in relevant cases and issues to the national scene, such as the relationship between taxation and development, the compliance costs of taxation, the tax evasion and the tax enforcement procedure. Given the above, it is intended to lay the groundwork for a general theory of Economic Analysis of Tax Law, contextualizing it with the Brazilian tax system

Contribuição ao estudo da isonomia na tributação sob a perspectiva da ordem econômica

The study aims to investigate the limits of state intervention via induction on Economic Order, especially in cases regarding tax equality, through the analysis of their effects on economic development and on free competition from the perspective of economic efficiency and the Constitution. Thus, the work seeks to demonstrate that the achievement of equality in taxation is important in that it strengthens the economic relations in terms of efficiency, protects competition and fosters economic development to reduce regional and social inequalities and other constitutional desiderata. A dissertation is characterized by interdisciplinarity and was divided into two parts. The first is to discuss the legal meaning of equality from the doctrinal analysis of the principle and the relationship between equality and justice in the economic sense without rejecting its philosophical content. It is noteworthy that hermeneutics and the philosophy of language are useful tools for achieving equality in presenting the pragmatic methodologies applicable to the subject in terms of corrective justice. Based on these general assumptions, is going to study the tax equality and their characteristics, the corollary of the ability to pay and its relation to the economic capacity and the issue of progressivity in taxation as an ideal of distributive justice. The second part concerns the legal foundations of Economic Order and its relation to extrafiscality as a means of economic regulation in order to investigate the efficiency of this induction in order to promote economic development, free competition and tax equality itself to reduce inequalities and distributing wealth. Within this context, we investigated the scope of the constitutional principles of economic order, free enterprise and free competition, and favored differential treatment for small and medium enterprises, the issue of regional development for the reduction of regional and social inequalities, the problem the "fiscal war" and finally the efficiency from the perspective of Economic Analysis of Law

Avaliação do crescimento e do custo da alimentação do pacu (Piaractus mesopotamicus Holmberg, 1887) submetido a ciclos alternados de restrição alimentar e realimentação

Avaliaram-se os efeitos da utilização de ciclos alternados de restrição alimentar e realimentação no crescimento do pacu, durante o período de engorda, e a viabilidade desta prática na produção comercial da espécie. Juvenis foram distribuídos em três tanques e submetidos a diferentes manejos alimentares, constituindo os tratamentos: A (alimentado ad libitum), B (restrição alimentar de 4 semanas, realimentado por 9 semanas) e C (6 semanas de restrição alimentar, realimentado por 7 semanas), em um total de 13 semanas por ciclo (4 ciclos experimentais). No final de cada ciclo alimentar, 20 peixes de cada tratamento foram amostrados e os dados biométricos registrados. Os valores obtidos para peso, comprimento total e fator de condição (K) foram submetidos a ANOVA e as médias comparadas pelo teste de Duncan. Os resultados mostraram que o tratamento C é o mais indicado somente para outono/inverno, promovendo maior crescimento, menor custo com ração, baixa conversão alimentar e maior receita líquida parcial. Entretanto, durante as estações mais quentes do ano (primavera/verão) outros programas de alimentação devem ser testados, utilizando-se períodos mais curtos de restrição alimentar. Quando se tratou da produção anual, o tratamento A respondeu melhor em termos de biomassa produzida, apesar do maior gasto com alimentação, visto que, com o aumento da temperatura, o crescimento dos peixes dos demais tratamentos ficou prejudicado.

Adubação nitrogenada de cobertura no feijoeiro de invernoprimavera em três sistemas de cultivo

The aim of this study was to evaluate the nitrogen topdressing influence in common bean irrigated (winter-spring), in the first year of no tillage implementation. The experimental design was split-plot with three replications in randomized blocks. The plots were formed by three types of ground cover, corn-grain, corn-grain intercropped with Brachiaria ruziziensis and only B. ruziziensis. The subplots were formed by five doses of nitrogen topdressing (0, 40, 80, 120 and 160 kg ha(-1)), using urea as nitrogen source. It was determined the dry mass of residue present as ground cover, the full flowering time, the leaf nitrogen content, the 100 grains mass, the grain yield, the processing income, the chemical soil properties and economic analysis of common bean grain yield. It was found the common bean grain productivity in succession to corn-grain was positively influenced by nitrogen fertilization, showing it is economically viable only when given 160 kg ha(-1) of nitrogen and the intercropping corn-grain and B. ruziziensis use is the best option when the common bean is sown in succession.

Comparação de sistemas de avaliação de dietas para bovinos no modelo de produção intensiva de carne. Suplementação do pasto para vacas na estação seca

Foram utilizadas 30 vacas da raça Canchim com 50 meses de idade e peso corporal médio de 471 kg, que receberam suplemento alimentar durante a estação seca de 1998, objetivando avaliar a precisão no desempenho estimado por diferentes sistemas de avaliação de dietas. Os suplementos, à base de silagem de milho, milho, polpa cítrica peletizada, farelo de algodão, farelo de soja e soja integral, seguiram as recomendações do Sistema de Proteína Metabolizável (MP); do Sistema de Proteína e Carboidratos Líquidos de Cornell (CNCPS); e do Sistema de Proteína Digestível no Intestino (PDI), para manutenção do peso corporal. A variação diária de peso corporal obtida não diferiu entre os tratamentos CNCPS, MP e PDI, com médias de 0,34; 0,33; e 0,19 kg/cab, respectivamente. Quando a produção de carne constituiu-se no objetivo único do sistema produtivo, a análise econômica revelou saldo de R$22,00; R$-44,73; e R$47,27/ha/ano, para os sistemas CNCPS, MP e PDI, respectivamente. Concluiu-se que os suplementos avaliados pelos sistemas proporcionaram resultados de desempenho animal compatíveis com os estimados.

Níveis de lisina em rações para frangos de corte determinados com base em uma abordagem econômica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)