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

Rejeito de xisto como adsorvente para remoção de fenol em águas produzidas na indústria de petróleo

Produced water is the main effluent linked to the activity of extraction of oil and their caring management is necessary due to the large volume involved, to ensure to minimize the negative impacts of discharges of these waters in the environment. This study aimed to analyze the use of retorted shale, which is a reject from the pyrolysis of pirobituminous shale, as adsorbent for the removal of phenols in produced water. The material was characterized by different techniques (grain sized analysis, thermal analysis, BET, FRX, FT-IR, XRD and SEM), showing the heterogeneity in their composition, showing its potential for the removal of varied compounds, as well as the phenols and their derivatives. For the analysis of the efficiency of the oil shale for the adsorption process, assays of adsorption balance were carried through, and also kinetic studies and dynamics adsorption, in the ETE of the UTPF of Petrobras, in Guamaré-RN. The balance assays shown a bigger conformity with the model of Langmuir and the kinetic model more adjusted to describe the adsorption of phenols in retorted shale was of pseudo-second order. The retorted shale presented a low capacity of adsorption of phenols (1,3mg/g), when related to others conventional adsorbents, however it is enough to the removal of these composites in concentrations presented in the produced water of the UTPF of Guamaré. The assays of dynamics adsorption in field had shown that the concentration of phenol in the effluent was null until reaching its rupture (58 hours). The results showed the possibility of use of the reject for removal of phenols in the final operations of the treatment process, removing as well, satisfactorily, the color and turbidity of the produced water, with more than 90% of removal

Aplicação de sistemas microemulsionados ácidos em acidificação de poços

Stimulation operations have with main objective restore or improve the productivity or injectivity rate in wells. Acidizing is one of the most important operations of well stimulation, consist in inject acid solutions in the formation under fracture formation pressure. Acidizing have like main purpose remove near wellbore damage, caused by drilling or workover operations, can be use in sandstones and in carbonate formations. A critical step in acidizing operation is the control of acid-formation reaction. The high kinetic rate of this reaction, promotes the consumed of the acid in region near well, causing that the acid treatment not achive the desired distance. In this way, the damage zone can not be bypassed. The main objective of this work was obtain stable systems resistant to the different conditions found in field application, evaluate the kinetic of calcite dissolution in microemulsion systems and simulate the injection of this systems by performing experiments in plugs. The systems were obtained from two non ionic surfactants, Unitol L90 and Renex 110, with sec-butanol and n-butanol like cosurfactants. The oily component of the microemlsion was xilene and kerosene. The acqueous component was a solution of HCl 15-26,1%. The results shown that the microemulsion systems obtained were stable to temperature until 100ºC, high calcium concentrations, salinity until 35000 ppm and HCl concentrations until 25%. The time for calcite dissolution in microemulsion media was 14 times slower than in aqueous HCl 15%. The simulation in plugs showed that microemulsion systems promote a distributed flux and promoted longer channels. The permeability enhancement was between 177 - 890%. The results showed that the microemulsion systems obtained have potential to be applied in matrix acidizing

Entre desvios e normas: infração juvenil feminina na cidade de Natal - RN

This paper presents some reflections on the social world of young female transgression. The context corresponds to those ones that obey social and educational measures in The Padre João Maria Education Centre (CEDUC), in Natal- RN. This behavior, according to the Statute of Children and Young (ECA, 1990), is defined as "conduct described as crime or misdemeanor." Our goal is to discuss aspects of the contexts in which young women are interacting with the universe of total institutional control mechanisms. Through the socio-anthropological analysis of the ethnographic practice in field research, it was necessary to question the concept of misuse engaged in the practice of penalties awarded to young women in the context of private freedom. So was built a frame relating the representations of the relations of gender, generation, the practice of violence and crime from the look on CEDUC/ Padre João Maria Education Centre

Reserva de cargos e empregos públicos a pessoas com deficiência: instituições federais de ensino no RN

With a focus on the need for effectiveness of fundamental rights of persons with disabilities, this dissertation held a scientific research to analyze the degree of implementation of reservation of positions and public jobs to people with disabilities in the Brazilian State, because the 1988 Federal Constitution expressly determined such a reservation in your article 37, VIII. Highlight that this subject is enough evidence, given the large number of open public competition in recent years in Brazil, as well as recent proposals to grant equal rights to blacks (Bill nº 6,738/2013). In addition, the wording the constitutional device comes fomenting heated discussions on the subject, which are flowing on the doors of the judiciary and are spicy because such protection Microsystem vulnerable group has several gaps in the regulation of this policy. However, the research produced, unlike other related theme, does not address the problem of inefficiency in its constitutional theory, that is, abstractly, but also focuses on a specific analysis of this ineffectiveness within Brazilian society, so that research based on a bibliographical analysis, plus a study case law, at the national level, as well as in field research, while case study, focusing on the technique of the analysis of everyday life, because it was believed that the degree of realization of the constitutional norm debated is not yet a satisfactory degree of effectiveness. Soon, the methodological procedures chosen confirmed such a hypothesis and contributed to the study of realization of the fundamental right to work of people with disabilities in Brazil, the light of a Constitutional State, proposing a constitutionally appropriate model the greater effectiveness of the constitutional norm studied

Inclusão de estudantes com deficiência nas instituíções de ensino superior da cidade do Natal/RN:análise das condições oferecidas no processo seletivo vestibular

The number of disabled students, who have entered the university, in Brazil, since the beginning of this century, is undergoing a speed growth. It is a change that follows a global trend that spreads an inclusive education policy and that has had a profound impact on Brazil, with import results in field researches. This subject has been highlighted due to the significant amount of disabled students enrolled in college institutions (IES), although it is still modest the number of studies about it, especially in what matters the assistance given to the candidates to a university entrance examination. The aim of this paper is to investigate how effectively Natal s IES apply the rules established in Brazilian law concerning disabled students, especially MEC/GM Circular Warning n. 277/96, in what respects the conditions given to disabled students preparing to enter a college. The investigation followed a qualitative methodological approach with support on an exploratory study. The data recollection employed questionnaire, semi-structured interview and documental analyses, and the data have been organized and assessed following Minayo s (1996) stages. What concerns the results, it was observed that none of the ten colleges inquired confirmed to possess places exclusively to disabled candidates; six of them, however, offer Special Examining Board in the selection process of disabled candidates. Among eighteen college bills, only two of them offered specific information related to services and resources offered by IES to the candidates who ask for especial assistance concerning examination. During the interviews, four managers avowed the preoccupation in offering an equal selection process, but two of them proved not dominate the subject. In conclusion, the investigated institutions managers do not still seem to respect the rule that guarantees to disabled candidates equal conditions during all the process of the university entrance examination. With this work, we hope do help changing this focus and contribute to new studies on disabled persons studying for a degree

Método de avaliação do gerenciamento de resíduos em canteiro de obras da construção civil : proposta baseada em empresas construtoras da cidade de Natal-RN

According to great concern between the developed industrial activities and resultant impacts over the environment, an association of several factors have occurred, procedures to the efficient management of the rotation between economical development and the environment have been improved. A research in field have been realized inside building sites of companies in order to provide knowledge about the implemented and accomplish actions according to the resolution from CONAMA nº307. Trough the interview among the representations of the companies and photographic survey in loco, such as, what makes the companies implement this management, reutilization and recycling, transport and disposition. The present study had as objective: analyze the insertion of the used tools to residuals management, proposing improvements, in a way that it can be easily identified during the procedures execution in the building sites of the building companies of the city of Natal/RN. To reach the goal, in the first place a revision of the pertinent literature was performed; there for, it can be seen the relation between residues management and environment sustainability, once it happens in a continued way it may prevent the waste and reduces the risk that the activities way bring to the employees, community and environment; once found the great difficult faced with regard to labors, material, equipment, project, planning, costumer s interference, furnisher. And still, it could be verified wich materials generate greater indexes of residues in the works and the main occurrences of waste and loss. However a greater transparency is needed coming from the high administration in the commitment with the continued actions, to make it so, there must be a cultural change inside the company. There for there will be a greater productivity and quality of the under taking such as costumer s satisfaction

Competitividade dos produtores rurais de cana-de-açúcar da região agreste do Rio Grande do Norte

Deregulation of the sugar-alcohol sector in the 90s meant that agribusiness firms begin a process of reorganization of their production structures to enhance their abilities to become competitive in the new scenario. This study aims to examine the Production Chain of Sugar cane in Agreste region of Rio Grande do Norte, with studies to contribute to the competitiveness of farmers giving grants for planning and implementing policies, programs and projects, public and / or private. The method used in the study was researching the literature on the history of sugar cane in Brazil, agribusiness management, production chains and competitiveness, in field research used a questionnaire to collect information from farmers. It is concluded that the rural producers of cane sugar in newborns are not competitive and therefore it is necessary policies and / or for private gain in competitiveness of producers and consequently the production chain. It is hoped that the study serves as a subsidy for those policies proposição

Otimização dos parâmetros de monopolos planares de microfita para aplicações em sistemas de banda ultra larga

This work presents a theoretical and experimental investigation about the properties of microstrip antennas for ultra-wideband systems. Configurations of elliptic monopoles with different eccentricities and circular monopoles are considered. Two prototypes for each antenna configuration were built, one with the typical microstrip configuration and the other is similar to the first, except for a small aperture in the ground plane. Therefore, this work proposes to modify the configuration of the ground plane of the monopoles designed adding a rectangular stub, in order to optimize and improve the performance of such structures. The obtained results show that the introduction of that rectangular aperture in the ground plane allows an improvement of the frequency response for the considered antenna propotypes. It is observed a good agreement between the measured and simulated results. Finally, some proposals for future works are presented

Sistemas de automação e supervisão do laboratório de avaliação dos processos de medição de vazão e BSW

During a petroleum well production process, It is common the slmultaneous oil and water production, in proportion that can vary from 0% up to values close to 100% of water. Moreover, the production flows can vary a lot, depending on the charaeteristies of eaeh reservoir. Thus being, the meters used in field for the flow and BSW (water in the oil) measurement must work well in wide bands of operation. For the evaluation of the operation of these meters, in the different operation conditions, a Laboratory will be built in UFRN, that has for objective to evaluate in an automatic way the processes of flow and BSW petroleum measurement, considering different operation conditions. The good acting of these meters is fundamental for the accuracy of the measures of the volumes of production liquid and rude of petroleum. For the measurement of this production, the petroleum companies use meters that should indicate the values with tha largast possible accuracy and to respect a series of conditions and minimum requirements, estabelished by the united Entrance ANP/INMETRO 19106/2000. The laboratory of Evafuation of the Processes of Measurement of Flow and BSW to be built will possess an oil tank basically, a tank of water, besides a mixer, a tank auditor, a tank for separation and a tank of residues for discard of fluids, fundamental for the evaluation of the flow metars and BSW. The whole process will be automated through the use of a Programmable Logicat Controller (CLP) and of a supervisory system.This laboratory besides allowing the evaluation of flow meters and BSW used by petroleum companies, it will make possible the development of researches related to the automation. Besides, it will be a collaborating element to the development of the Computer Engineering and Automation Department, that it will propitiate the evolution of the faculty and discente, qualifying them for a job market in continuous growth. The present work describes the project of automation of the laboratory that will be built at of UFRN. The system will be automated using a Programmable Logical Controller and a supervisory system. The programming of PLC and the screens of the supervisory system were developed in this work

Antenas monopolo planar com patch em anel circular para sistemas UWB

The microstrip antennas are largely used in wireless communication systems due to their low cost, weight, less complex construction and manufacturing, in addition to its versatility. UWB systems have emerged as an alternative to wireless communications over short distances because they offer of higher capacity and lower multipath distortion than other systems with the same purpose. Combining the advantages of microstrip antennas to the characteristics of UWB, it is possible to develop more and more smaller devices, with diverse geometries to operate satisfactorily in these systems. This paper aims to propose alternatives to microstrip antennas for UWB systems operate in the range between 3.1 and 10.6 GHz, with a patch on circular ring. Some techniques are analyzed and employed to increase the bandwidth of proposed antenna: the insertion of a parasitic elements and a rectangular slit in the displaced ground plane. For this, key issues are presented as the basic principles of UWB systems, the fundamental theory of antennas and microstrip antennas. The simulations and experimental characterization of constructed antennas are presented, as well as analysis of parameters such as bandwidth and radiation pattern

Desenvolvimento de antenas de microfita com aberturas nos patches condutores através do método da segmentação

Microstrip antennas are widely used in modern telecommunication systems. This is particularly due to the great variety of geometries and because they are easily built and integrated to other high frequency devices and circuits. This work presents a study of the properties of the microstrip antenna with an aperture impressed in the conducting patch. Besides, the analysis is performed for isotropic and anisotropic dielectric substrates. The Multiport Network Model MNM is used in combination with the Segmentation Method and the Greens function technique in the analysis of the considered microstrip antenna geometries. The numerical analysis is performed by using the boundary value problem solution, by considering separately the impedance matrix of the structure segments. The analysis for the complete structure is implemented by choosing properly the number and location of the neighboor element ports. The numerial analysis is performed for the following antenna geometries: resonant cavity, microstrip rectangular patch antenna, and microstrip rectangular patch antenna with aperture. The analysis is firstly developed for microstrip antennas on isotropic substrates, and then extended to the case of microstrip antennas on anisotropic substrates by using a Mapping Method. The experimental work is described and related to the development of several prototypes of rectangular microstrip patch antennas wtih and without rectangular apertures. A good agreement was observed between the simulated and measured results. Thereafter, a good agreement was also observed between the results of this work and those shown in literature for microstrip antennas on isotropic substrates. Furthermore, results are proposed for rectangular microstrip patch antennas wtih rectangular apertures in the conducting patch