Otimização e análise mecânica de pastas geopoliméricas para uso em poços sujeitos à injeção cíclica de vapor

Oil wells subjected to cyclic steam injection present important challenges for the development of well cementing systems, mainly due to tensile stresses caused by thermal gradients during its useful life. Cement sheath failures in wells using conventional high compressive strength systems lead to the use of cement systems that are more flexible and/or ductile, with emphasis on Portland cement systems with latex addition. Recent research efforts have presented geopolymeric systems as alternatives. These cementing systems are based on alkaline activation of amorphous aluminosilicates such as metakaolin or fly ash and display advantageous properties such as high compressive strength, fast setting and thermal stability. Basic geopolymeric formulations can be found in the literature, which meet basic oil industry specifications such as rheology, compressive strength and thickening time. In this work, new geopolymeric formulations were developed, based on metakaolin, potassium silicate, potassium hydroxide, silica fume and mineral fiber, using the state of the art in chemical composition, mixture modeling and additivation to optimize the most relevant properties for oil well cementing. Starting from molar ratios considered ideal in the literature (SiO2/Al2O3 = 3.8 e K2O/Al2O3 = 1.0), a study of dry mixtures was performed,based on the compressive packing model, resulting in an optimal volume of 6% for the added solid material. This material (silica fume and mineral fiber) works both as an additional silica source (in the case of silica fume) and as mechanical reinforcement, especially in the case of mineral fiber, which incremented the tensile strength. The first triaxial mechanical study of this class of materials was performed. For comparison, a mechanical study of conventional latex-based cementing systems was also carried out. Regardless of differences in the failure mode (brittle for geopolymers, ductile for latex-based systems), the superior uniaxial compressive strength (37 MPa for the geopolymeric slurry P5 versus 18 MPa for the conventional slurry P2), similar triaxial behavior (friction angle 21° for P5 and P2) and lower stifness (in the elastic region 5.1 GPa for P5 versus 6.8 GPa for P2) of the geopolymeric systems allowed them to withstand a similar amount of mechanical energy (155 kJ/m3 for P5 versus 208 kJ/m3 for P2), noting that geopolymers work in the elastic regime, without the microcracking present in the case of latex-based systems. Therefore, the geopolymers studied on this work must be designed for application in the elastic region to avoid brittle failure. Finally, the tensile strength of geopolymers is originally poor (1.3 MPa for the geopolymeric slurry P3) due to its brittle structure. However, after additivation with mineral fiber, the tensile strength became equivalent to that of latex-based systems (2.3 MPa for P5 and 2.1 MPa for P2). The technical viability of conventional and proposed formulations was evaluated for the whole well life, including stresses due to cyclic steam injection. This analysis was performed using finite element-based simulation software. It was verified that conventional slurries are viable up to 204ºF (400ºC) and geopolymeric slurries are viable above 500ºF (260ºC)

Formulação de grautes leves para a cimentação de poços de petróleo onshore

Grautes are dry mixes with hydraulic characteristics widely used in construction. This material comprises cement, mineral additives and dosed in accordance with the desired properties. The use of grautes in cementing oil wells potentially increases the precision in the composition of the mixture, since it is requires only the addition of the mixing water before its pumping. Such benefit may be availed in cementing wells since the formulations grautes meet the temperature and pressure characteristics typical of wells. The objective of this study is to evaluate the effect of adding different percentages of industrial minerals properties of light grautes for onshore oil wells. For the formulation of the employees were grautes light industrial minerals and waste minerals abundant in the Northeast, in addiction to Portland cement and chemical additives Special class. Grautes were formulated with densities between 1.55 g/cm3 (13.0 lb/gal) and 1.68 g/cm3 (14 lb/gal). Tests results showed that grautes with higher density in the range studied meet the specifications for cementation of shallow wells onshore. The compositions lighter can also be adjusted for applying the material in the cementation of oil wells

Efeito da adição de carbonatos em formulação de massa para revestimento cerâmico utilizando matérias-primas do Piauí

Piauí state is a major producer of traditional red ceramic burning as bricks, tiles and ceramic tiles, with its main production center located in the city of Teresina. The state has large reserves of raw materials that can be used in the ceramic coating as clays, quartz, talc and carbonates. However, in the preparation of ceramic bodies using only a mixture of clays with different characteristics. The study aims to evaluate the effect of adding two types of carbonates in the ceramic semiporous mass coating produced in Piauí and then to verify the potential use of these carbonates as supplementary raw material product manufactured or the feasibility of obtaining a ceramic plate that meets the specifications for the porous coating. For this, were characterized the ceramic Piauí coating mass, a calcitic carbonate and a dolomitic, were made in the levels of 2, 4, 8, 16, and 32%. The masses were formed by pressing and burneds in two environments: a laboratory furnace (1080°C, 1120°C, 1140°C, and 1160°C) and an industrial furnace (1140°C). Then, following tests of linear shrinkage water absorption, apparent porosity, bulk density and flexural strength. Furthermore, the fired specimens were tested for their macrostructure and microstructure. The results showed the possibility of using the carbonate in ceramic mass flooring produced in Piauí, as added in small proportions improved dimensional stability and increased mechanical strength of ceramics pieces. It also proved itself possible to produce porous coating when added in higher levels

Formulação de bloco intertravado cerâmico com adição de resíduos urbanos e industriais

The production of waste from urban and industrial activities is one of the factors of environmental contamination and has aroused attention of the scientific community, in the sense of its reuse. On the other hand, the city of Salvador/Ba, with approximately 262 channels, responsible for storm water runoff, produces every year, by the intervention of cleaning and clearing channels, a significant volume of sediments (dredged mud), and thus an appropriate methodology for their final destination. This study aims to assess the influence of incorporation of these tailings in arrays of clay for production of interlocked block ceramic, also known as ceramic paver. All the raw materials from the metropolitan region of Salvador (RMS) were characterized by x-ray fluorescence, x-ray diffraction, thermal analysis (TG and TDA), particle size analysis and dilatometry. With the use of statistical experimental planning technique, ternary diagram was defined in the study region and the analyzed formulations. The specimens were prepared with dimensions of 60x20x5mm³, by uniaxial pressing of 30 MPa and after sintering at temperatures of 900°, 1000º and 1100ºC the technological properties were evaluated: linear shrinkage, water absorption, apparent porosity, apparent specifies mass, flexural rupture and module. For the uniaxial compression strength used cylindrical probe body with Ø 50 mm. The standard mass (MP) was prepared with 90% by weight of clay and 10% by weight of Channel sediment (SCP), not being verified significant variations in the properties of the final product. With the incorporation of 10% by weight of manganese residue (PFM) and 10% by weight of the Ceramic waste (RCB) in the mass default, in addition to adjusting the plasticity due to less waste clay content, provided increased linear firing shrinkage, due the significant concentration of K2O, forming liquid phase at low temperature, contributing to decreased porosity and mechanical resistance, being 92,5 MPa maximum compressive strength verified. After extract test leachate and soluble, the piece containing 10% of the PFM, was classified as non-hazardous and inert material according to NBR10004/04 ABNT. The results showed the feasibility on using waste, SCP, RCB and PFM clay mass, at temperatures above 900ºC, paver ceramic production, according to the specifications of the technical standards, so that to exceed the 10% of the PFM, it becomes imperative to conduct studies of environmental impacts

Influência da vermiculita expandida na formulação de pastas leves para evitar a migração de gás em cimentação de poços petrolíferos

The gas migration during the cementing of wells is one of the main problems of oil wells engineering. Its occurrence can cause severe problems since shortly to loss of control of the well after cementation. Recently, 20/04/2010 In an accident of major proportions in the Gulf of Mexico, among other factors, faulty cementing operation provided the gas migration, causing the accident, in which 11 people died and 17 were injured occurred. Besides the serious consequences that can be caused by gas migration, remediation of the problem, which is made by injecting cement in damaged areas, usually involves additional costs and is not always effective. Therefore, preventing gas migration to be preferred. Some methods are used to prevent the migration of the pressurized gas as the annular space, application of pressure pulses, reducing the height of the cement column compressible cement pastes of low permeability, pastes and to control free filtered water, and binders of thixotropic cement expandable and flexible. Thus, the cement pastes used to prevent gas migration must meet the maximum these methods. Thus, this study aimed to formulate a cement paste to prevent gas migration, using the expanded vermiculite, and evaluate the behavior of the folder trials necessary for use in oil wells. Free water content, rheological properties, compressive strength, loss of liquid phase sedimentation of solids, specific weight, thickening time and gas migration: The following tests were performed. The results show that meets the specifications paste formulated for use in oil wells and the use of expanded vermiculite contribute to the absorption of free water, thixotropy and low density. The absorption of free water is proven to result in zero percentage test free water content, thixotropy is observed with the high value of the initial gel strength (Gi) in testing rheological properties and low density is proven in test weight specific

Estudo de Matérias-Primas do Rio Grande do Norte para Uso em Revestimento Poroso: Influência do teor de dolomita e temperatura de calcinação nas propriedades físico-mecânicas

The state of Rio Grande do Norte presents a great potentiality for the production of ceramic tiles because of having natural raw material in quantity and quality making its economical exploration possible, beyond the great energetic differential of the state, the natural gás. This works aims to study the influence of the dolomite and granulometry concentration and calcinations temperature in the obtaining of formulations for porous coverings which have to be coherent to the project,s specifications. The experiments have involved the physical-chemical and mineralogical characterizations of raw materials and mechanical tests in the dry and burnt proof bodies preceding a mixture experiment planning with the use of the response surface methodology, in order to get the best raw materials combinations to produce a ceramic mass with specific properties. The twelve ceramic masses studied in this work were prepared by the via dry process, characterized, shaped by uniaxial pressing and sinterized in the temperatures of 940ºC, 1000ºC, 1060ºC, 1120ºC and 1180ºC, using a fast burning cycle. The crystalline phases formed during the sintering in the temperatures in study have revealed the presence of anorthite and diopside beyond quartz with a remaining phase. These phases were the main responsible ones by the physical- mechanical properties of the sinterized proof bodies. The proof bodies after the sintering stage have presented water absorption higher than 10% and a good dimensional stability in all studied temperatures. However, the flexural breaking strength results in the temperatures of 940ºC, 1000ºC and 1060ºC, under the temperature zone of the vitrification of ceramic whiteware do not reach the flexural breaking strength specific for the porous wall tile (15 MPa), but in the temperature of 1120ºC next to the vitrification temperature zone, some whiteware ceramic (formulations) has reached the specified value for the porous wall tile. The results of this work have showed that the studied raw materials have great importance for used in the production of porous wall tiles (BIII)

Avaliação térmica dos resíduos da destilação atmosférica das blendas - biodiesel/diesel

The worldwide concern regarding the use of sustainable energy and preserving the environment are determining factors in the search for resources and alternative sources of energy and therefore fuel less aggressive nature. In response to these difficulties Biodiesel has emerged as a good solution because it is produced from renewable sources, produces burns cleaner and is easily reproducible. This work was synthesized with biodiesel oil, sunflower via homogeneous catalysis in the presence of KOH, with and without the use of BHT and subsequently added to the blends BX (a proportion of biodiesel X = 5, 10, 15 and 20 %). Atmospheric distillation of the analysis, performed in blends with and without BHT were collected residue generated by each sample and performed a study heat from the thermogravimetric analysis at a heating rate of 10 °C*min-1, nitrogen atmosphere and heating to 600 °C. According to the specifications of Resolution N 7/2008 for biodiesel, it was found that the synthesized material was in accordance with the specifications. For blends showed that the samples are in accordance with the Resolution of ANP N 42/2009. From the TG / DTG curves of the samples of biodiesel, blends and waste can be seen that these show a single loss of thermal decomposition concerning constituents present in each sample. The blends without BHT with ratios of 5%, 10% and 15% biodiesel showed a lower amount of waste (1,07%; 1,09% e 1,10%) to mineral diesel (1,15%). Therefore, it is concluded that the addition of biodiesel with diesel mineral can improve some physico-chemical parameters, but also, depending on the added amount, decreasing the amount of waste generated. This fact is of great importance because the carbonaceous residue can cause problems in mechanical equipment and parts for vehicles, causing more frequent maintenance, and this is not desirable

Estudo térmico dos resíduos gerados da destilação atmosférica das misturas diesel/biodiesel de dendê

The growing world demand for energy supplied by fossil fuels, a major contributor to the emission of pollutants into the atmosphere and causing environmental problems, has been encouraging governments and international organizations to reflect and encourage the use of alternative renewable sources. Among these new possibilities deserves attention biodiesel, fuel cleaner and easy to reproduce. The study of new technologies involving that source is necessary. From this context, the paper aims at analyzing the thermal stability by thermogravimetric analysis, of the waste generated from atmospheric distillation of mixtures with ratios of 5, 10, 15 and 20% palm biodiesel in diesel with and without addition of BHT antioxidant. It was synthesized biodiesel through palm oil, via homogeneous catalysis in the presence of KOH, with and without the use of BHT and subsequently added to the diesel common indoor type (S1800) from a gas station BR. The diesel was already added with 5% biodiesel, and thus the proportions used for these blends were subtracted from the existing ratio in diesel fuel, resulting in the following proportions palm oil biodiesel: 0% (B5), 5% (B10), 10 % (B15) and 15% (B20). From atmospheric distillation analysis, performed in mixtures with and without BHT were collected residue generated by each sample and performed a thermal study from the thermogravimetric analysis at a heating rate of 10 °C.min-1, nitrogen atmosphere and heating to 600 ° C. According to the specifications of Resolution No. 7/2008 for biodiesel, it was found that the material was synthesized in accordance with the specifications. For mixtures, it was noted that the samples were in accordance with the ANP Resolution No. 42/2009. Given the TG / DTG curves of the samples of waste mixtures with and without BHT antioxidant was able to observe that they showed a single stage of thermal decomposition attributed to decomposition of heavy hydrocarbons and esters and other heavier constituents of the waste sample weighed. The thermal behavior of residues from atmospheric distillation of mixtures of diesel / biodiesel is very important to understand how this affects the proper functioning of the engine. A large amount of waste can generate a high content of particulate material, coke formation and carbonaceous deposits in engine valves, compromising their performance

Estudo da formulação de pré-misturas secas para a cimentação de poços em terra

An economical solution for cementing oil wells is the use of pre-prepared dry mixtures containing cement and additives. The mixtures may be formulated, prepared and transported to the well where is added water to be pumped.Using this method, becomes dispensable to prepare the cement mixes containing additives in the cementing operation, reducing the possibility of error. In this way, the aim of this work is to study formulations of cement slurries containing solid additives for primary cementing of oil wells onshore for typical depths of 400, 800 and 1,200 meters. The formulations are comprised of Special Class Portland cement, mineral additions and solids chemical additives.The formulated mixtures have density of 1.67 g / cm ³ (14.0 lb / gal). Their optimization were made through the analysis of the rheological parameters, fluid loss results, free water, thickening time, stability test and mechanical properties.The results showed that mixtures are in conformity the specifications for cementing oil wells onshore studied depths

Controle de qualidade físico-químico e biodisponibilidade relativa em ratos de suspensões orais de naproxeno sódico obtidas de farmácias de manipulação na cidade do Natal RN

Compounded medicines have been reported by the ANVISA due to decreased of the therapeutic response or toxicity of these formulations. The aim of this work was to investigate the physicochemical quality control among naproxen sodium oral suspensions 25 mg/mL obtained from six compounding pharmacies (A, B, C, D, E and F) and the manufactured suspension (R). In the quality control test, the tests of pH, content, homogeneity, volume and physical and organoleptic characteristics were performed according to the Brazilian Pharmacopoeia. The analytical method for determination of naproxen in suspensions was validate. This method showed excellent precision, accuracy, linearity and specificity. In the content test the suspensions B, C and E showed lower value and the F suspension showed a high value of the content. The products C and E were disapproved in the description of the physical and organoleptic characteristics test. In the pH test, three suspensions were outside specifications (C, E and F). Only the products R, A and D showed satisfactory results in these tests and therefore they were approved for relative bioavailability test. The R, A and D suspensions were orally administered to Wistar rats and the blood samples were taken at time intervals of 10, 20, 40, 60 min, 3, 4, 6, 24 and 48 h. The plasma samples were immediately stored at 80 ºC until analysis of HPLC. The bioanalytical method validation showed specificity, linearity (R2 0.9987), precision, accuracy, good recovery and stability. The chromatographic conditions were: flow rate of 1.2 mL.min-1 with a mobile phase of acetonitrile : sodium phosphate buffer pH 4.0 (50:50, v/v) at 280 nm, using a C18 column. The confidence interval of 90% for the Cmax and AUCt ratio was within the range of 80 - 125% proposed by the FDA. Only one suspension, obtained from the compounding pharmacy D, was considered bioequivalent to the rate of absorption under the conditions proposed by this study. Thus, the results indicate the need for strict supervision from the relevant authorities to ensure the patient safety and the quality of compounded drugs by pharmacies

Nota científica: padrão de distribuição de alguns bicos hidráulicos

O conhecimento sobre o padrão de deposição de bicos pulverizados é essencial para uma boa seleção e posicionamento dos mesmos em um equipamento pulverizador. O presente trabalho foi conduzido com o objetivo de se conhecer os padrões de deposição de alguns bicos pulverizadores disponíveis no mercado brasileiro. Dois ou três exemplares de cada tipo de bico foram testados em uma mesa de prova, constituída de uma chapa inclinada corrugada, construída segundo as especificações da Organização Mundial da Saúde para testes de bicos pulverizadores. Todos os bicos foram testados à pressão de 276 kN/m2 (40 libras/p ol2), com exceção dos bicos de impacto (Polijet) que foram testado s à pressão de 97 kN/m2 (14 libras/ pol 2). Ressalvando-se o pequeno número de exemplares testados por cada tipo, os resultados indicaram que: a) - existem diferenças entre a vazão estipulada pelos fabricantes e a vazão real, sendo esta diferença, acentuada para alguns casos; b) - foram observadas diferenças apreciáveis nos padrões de deposição entre as repetições nos bicos Polijet azul e Polijet vermelho (ICI) e no bico JD 14 -2 (Jacto) ; c) - os bicos 80 02 e 11003 (Spraying Systems), 80-03 e X3 (Hatsuta), JD 14-1 (Jacto) e Albuz verde (Albuz) apresentaram padrão de deposição uniforme entre as repetições; d) - considerando as variações observadas recomendam-se cuidadosos testes dos bicos, principalmente naqueles empregados nos trabalhos de experimentação, para possibilitar a escolha de um lote uniforme, para melhor controle da distribuição e dosagem dos produtos pulverizados.

Utilização do controle estatístico do processo para monitoramento do peso médio de cápsulas de Tuberculostáticos: estudo de caso no NUPLAM- RN

This Master Thesis presents a case study on the use of Statistical Process Control (SPC) at the Núcleo de Pesquisas em Alimentos e Medicamentos (NUPLAM). The SPC basic tools have been applied in the process of the tuberculostáticos drugs encapsulation, primarily concerning the objective to choose, between two speeds, which one is the best one to perform the tuberculostatics encapsulation. Later on, with the company effectively operating, the SPC was applied intending to know the variability of the process and, through the tracking of the process itself, to arrive at an estimated limit for the control of future lots of tuberculostatics of equal dosage. As special causes were detected acting in the process, a cause-and-effect diagram was built in order to try to discover, in each factor that composes the productive process, the possible causes of variation of the capsules average weight. The hypotheses raised will be able to serve as a base for deepened the study to eliminate or reduce these interferences in the process. Also a study on the capacity of the process to attend the specifications was carried out, and this study has shown the process´s inaptitude to take care of them. However, on the side of NUPLAM exists a real yearning to implant the SPC and consequently to improve the existing quality already present on its medicines

Análise e otimização de superfícies seletivas de Frequência utilizando redes neurais artificiais e algoritmos de otimização natural

The bidimensional periodic structures called frequency selective surfaces have been well investigated because of their filtering properties. Similar to the filters that work at the traditional radiofrequency band, such structures can behave as band-stop or pass-band filters, depending on the elements of the array (patch or aperture, respectively) and can be used for a variety of applications, such as: radomes, dichroic reflectors, waveguide filters, artificial magnetic conductors, microwave absorbers etc. To provide high-performance filtering properties at microwave bands, electromagnetic engineers have investigated various types of periodic structures: reconfigurable frequency selective screens, multilayered selective filters, as well as periodic arrays printed on anisotropic dielectric substrates and composed by fractal elements. In general, there is no closed form solution directly from a given desired frequency response to a corresponding device; thus, the analysis of its scattering characteristics requires the application of rigorous full-wave techniques. Besides that, due to the computational complexity of using a full-wave simulator to evaluate the frequency selective surface scattering variables, many electromagnetic engineers still use trial-and-error process until to achieve a given design criterion. As this procedure is very laborious and human dependent, optimization techniques are required to design practical periodic structures with desired filter specifications. Some authors have been employed neural networks and natural optimization algorithms, such as the genetic algorithms and the particle swarm optimization for the frequency selective surface design and optimization. This work has as objective the accomplishment of a rigorous study about the electromagnetic behavior of the periodic structures, enabling the design of efficient devices applied to microwave band. For this, artificial neural networks are used together with natural optimization techniques, allowing the accurate and efficient investigation of various types of frequency selective surfaces, in a simple and fast manner, becoming a powerful tool for the design and optimization of such structures

Supervisório Inteligente de Processos na Idústria do Petróleo e Gás :Aplicação em uma Coluna de Destilação Simulada Integrada a Instrumentação Real

The need to implement a software architecture that promotes the development of a SCADA supervisory system for monitoring industrial processes simulated with the flexibility of adding intelligent modules and devices such as CLP, according to the specifications of the problem, it was the motivation for this work. In the present study, we developed an intelligent supervisory system on a simulation of a distillation column modeled with Unisim. Furthermore, OLE Automation was used as communication between the supervisory and simulation software, which, with the use of the database, promoted an architecture both scalable and easy to maintain. Moreover, intelligent modules have been developed for preprocessing, data characteristics extraction, and variables inference. These modules were fundamentally based on the Encog software

Arquitetura para aplicações interativas imersivas de televisão digital

In this work, we propose a new approach to Interactive Digital Television (IDTV), aimed to explore the concepts of immersivity. Several architectures have been proposed to IDTV, but they did not explore coherently questions related to immersion. The goal of this thesis consists in defining formally what is immersion and interactivity for digital TV and how they may be used to improve user experience in this new televisive model. The approach raises questions such as the appropriate choice of equipment to assist in the sense of immersion, which forms of interaction between users can be exploited in the interaction-immersion context, if the environment where an immersive and interactive application is used can influence the user experience, and which new forms of interactivity between users, and interactivity among users and interactive applications can be explored with the use of immersion. As one of the goals of this proposal, we point out new solutions to these issues that require further studies. We intend to formalize the concepts that embrace interactivity in the brazilian system of digital TV. In an initial study, this definition is organized into categories or levels of interactivity. From this point are made analisis and specifications to achieve immersion using DTV. We pretend to make some case studies of immersive interactive applications for digital television in order to validate the proposed architecture. We also approach the use of remote devices anda proposal of middleware architecture that allows its use in conjunction with immersive interactive applications