Cinemática de partículas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo: avaliação durante paradas operacionais

The new oil reservoirs discoveries in onshore and ultra deep water offshore fields and complex trajectories require the optimization of procedures to reduce the stops operation during the well drilling, especially because the platforms and equipment high cost, and risks which are inherent to the operation. Among the most important aspects stands out the drilling fluids project and their behavior against different situations that may occur during the process. By means of sedimentation experiments, a correlation has been validated to determe the sedimentation particles velocity in variable viscosity fluids over time, applying the correction due to effective viscosity that is a shear rate and time function. The viscosity evolution over time was obtained by carrying out rheologic tests using a fixed shear rate, small enough to not interfere in the fluid gelling process. With the sedimentation particles velocity and the fluid viscosity over time equations an iterative procedure was proposed to determine the particles displacement over time. These equations were implemented in a case study to simulate the cuttings sedimentation generated in the oil well drilling during stops operation, especially in the connections and tripping, allowing the drilling fluid project in order to maintain the cuttings in suspension, avoiding risks, such as stuck pipe and in more drastic conditions, the loss of the well

Desenvolvimento de sistemas de aditivos químicos para aplicação em cimentações de poços de petróleo

The primary cementing is an important step in the oilwell drilling process, ensuring the mechanical stability of the well and the hydraulic isolation between casing and formation. For slurries to meet the requirements for application in a certain well, some care in the project should be taken into account to obtain a cement paste with the proper composition. In most cases, it is necessary to add chemicals to the cement to modify its properties, according to the operation conditions and thus obtain slurries that can move inside the jacket providing a good displacement to the interest area. New technologies of preparation and use of chemicals and modernization of technological standards in the construction industry have resulted in the development of new chemical additives for optimizing the properties of building materials. Products such as polycarboxylate superplasticizers provide improved fluidity and cohesion of the cement grains, in addition to improving the dispersion with respect to slurries without additives. This study aimed at adapting chemical additives used in civil construction to be used use in oilwell cement slurries systems, using Portland cement CPP-Special Class as the hydraulic binder. The chemical additives classified as defoamer, dispersant, fluid loss controller and retarder were characterized by infrared absorption spectroscopy, thermogravimetric analyses and technological tests set by the API (American Petroleum Institute). These additives showed satisfactory results for its application in cement slurries systems for oil wells. The silicone-based defoamer promoted the reduction of air bubbles incorporated during the stirring of the slurries. The dispersant significantly reduced the rheological parameters of the systems studied. The tests performed with the fluid loss controller and the retarder also resulted in suitable properties for application as chemical additives in cement slurries

Efeito da adição de cargas minerais leves na resistência mecânica de grautes para cimentação de poços offshore

The preparation of cement slurries for offshore well cementing involves mixing all solid components to be added to the mixing water on the platform. The aim of this work was to study the formulation of pre-prepared dry mixtures, or grouts, for offshore oilwell cementing. The addition of mineral fillers in the strength of lightweight grouts applied for depths down to 400 m under water depths of 500 m was investigated. Lightweight materials and fine aggregates were selected. For the choice of starting materials, a study of the pozzolanic activity of low-cost fillers such as porcelain tile residue, microsilica and diatomaceous earth was carried out by X-ray diffraction and mechanical strength tests. Hardened grouts containing porcelain tile residue and microsilica depicted high strength at early ages. Based on such preliminary investigation, a study of the mechanical strength of grouts with density 1.74 g/cm3 (14.5 lb/gal) cured initially at 27 °C was performed using cement, microsilica, porcelain tile residue and an anti-foaming agent. The results showed that the mixture containing 7% of porcelain tile residue and 7% of microsilica was the one with the highest compressive strength after curing for 24 hours. This composition was chosen to be studied and adapted for offshore conditions based on testes performed at 4 °C. The grout containing cement, 7% of porcelain tile residue, 7% of active silica and admixtures (CaCl2), anti-foaming and dispersant resulted satisfactory rheology and mechanical strength after curing for 24 hours of curing

Metodologia para avaliação de cinemática de partículas gasosas em fluidos de viscosidade variável com o tempo e sua aplicação na construção de poços de petróleo

Many challenges have been presented in petroleum industry. One of them is the preventing of fluids influx during drilling and cementing. Gas migration can occur as result of pressure imbalance inside the well when well pressure becomes lower than gas zone pressure and in cementing operation this occurs during cement slurry transition period (solid to fluid). In this work it was developed a methodology to evaluate gas migration during drilling and cementing operations. It was considered gel strength concept and through experimental tests determined gas migration initial time. A mechanistic model was developed to obtain equation that evaluates bubble displacement through the fluid while it gels. Being a time-dependant behavior, dynamic rheological measurements were made to evaluate viscosity along the time. For drilling fluids analyzed it was verified that it is desirable fast and non-progressive gelation in order to reduce gas migration without affect operational window (difference between pore and fracture pressure). For cement slurries analyzed, the most appropriate is that remains fluid for more time below critical gel strength, maintaining hydrostatic pressure above gas zone pressure, and after that gels quickly, reducing gas migration. The model developed simulates previously operational conditions and allow changes in operational and fluids design to obtain a safer condition for well construction

EMPRESAS DA CONSTRUÇÃO CIVIL DO MUNICÍPIO DE ARACAJU-SE: Percepções sobre Responsabilidade Social Empresarial

The companies are part of an important segment of the society, besides, it exercises a significant contribution, being also responsible for helping in the improvement of the quality of life of the population. Like this being, to present research looked for to investigate the perception that the entrepreneurs of the building site of Aracaju/SE have concerning the theme Business Social Responsibility (RSE). besides the perceptions, it was part also of the research, to know the entrepreneur's of the building site social construction and the possible practices of Social Responsibility. The research grew in two different moments. The first looked for the theoretical embasamento, trying to study the economical sociology, understanding the effects provoked by the economy, understanding to you reason them that you/they took to the appearance of the perceptions that you/they permeate the historicity among the market, the nascedouro of the associations as company and his/her dynamics in the society. It was also researched, the concept of social responsibility in national and local extent, as well as, the contextualização of the state of Sergipe, detaching the municipal district of Aracaju, and describing how it happened his/her development starting from what is considered urbanization. In the second moment, the accomplishment of interviews in five companies, allowed to notice the entrepreneurs' perception concerning business social responsibility, as well as, actions of different characteristics in four of the samples. In these actions, they are patronage in cultural events, donations of projects for charity institutions, the concern with the preservation of the environment in the use of work materials ecologically correct, preventive health and employees' training. Concluding the research, I introduce the conclusions which it allowed to arrive me, and I point some suggestions for future researches that enlarge the reflection on this theme

A construção de um estilo de vida: família e relações de gênero na participação do projeto ético-político renovado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Pedagogia Freinet: a construção de uma práxis em turmas de 5ª a 8ª séries

Ce travail que nous venons de présenter apport une systématisation sur la viabilité de la praxis de l´éducateur français Célestin Freinet (1896-1996). Il s´agit d´une étude qualificative, recherche-action, développée dans une école coopérative l´ École Freinet à Natal/RN Brésil, auprès des élèves du 5ème et 8ème séries de l´Enseignement Fondamental. Le problème central que nous a amené à cette recherche, a été le fait de vérifier les progressions dans la production scientifique et dans les pratiques des enseignants qui ont à la charge l´Éducation Infantine et les premières séries de l´Enseignement Fondamental. Tout cela en tenant compte en concevoir l´élève en tant que sujet actif de son apprentissage et coresponsable à l´organisation du travail scolaire. Toutefois, qaund-il s´agit des quatre dernières séries de l´Enseignement Fondamental (5ème au 8ème séries), les propositions progressistes sont prises comme quelque chose pratiquement impossible d´en mettre en marche. Pour attenuer la lacune théorique sur le sujet, nous avons offert un texte significatif pour les enseignants d´une façon générale, les chercheurs de l´académie et pour l´écolechamp de la recherché. Tout cela par le fait de ne pas donner de priorité à une technique ou à un principe, en particulier. Cette pédagogie est discutée autant que possible dans son contexte global et aussi sur le comment s´est manifestée dans sa práxis . Nous avons mis en relief les aspects importants pour le fonctionnement de la salle de classe, aussi que les estratégies utilisées pour la construction, communication et documentation des connaissances L´intervention nous a permis de construire l´objet par la réflexion en action, à partir des données obtenues pendant les observations, les entretiens, les enterviews, les moments d´études et de la quête des textes écrits. L´analyse a été faite à la lumière de la methodologie comprehensive (Kaufmann, 1996), entrelacée au materiau empirique et à la théorie. Cette forme d´analyse nous a permis d´obtenir la logique dans l´ensemble comme nous crayons que doit caracteriser la recherche aux Sciences Humaines et Sociales. Les considérations finales mettent l´accent d´un côté sur l´efficacité de la pédagogie Freinet, pour orienter le processus de l´enseignement apprentissage, en tous les dégres de l´enseignement et de l´autre côté nous montre la nécessité urgente de l´équipe de l´école champ de la recherche, de qualifier sa pratique à partir des références théoriques-pratiques de la pédagogie Freinet

Estudo do comportamento mecânico de areias artificialmente cimentadas

Soil improved with the addition of cement have been utilized as an alternative to the construction of various types of geotechnical works, almost always present economic and environmental advantages. This paper presents a study on the usage of cement in the improvement of mechanical properties of sandy soils, characteristic of the region of Natal, collected from its dunes. This research was made in order to analyze the influence of cement content, voids, and also including water immersion and confining pressure. Samples molded from cement-soil mixtures were tested for unconfined compression tests and triaxial tests. The samples had the percentage of cement mixed in 2.5%, 5% and 10% by weight. The cement agent used was the Portland Cement of High Early strength(CPV-ARI), which promoted agility to the experimental procedure for presenting a rapid gain in strenght. The void ratio used ranged from 0.7 (more compact), 0,9 and 1,1(softer). The soil under study can be considered as pure sand. In general, it can be stated that the larger the amount of cement added to the sand studied is, the greater ultimate strength will be. Likewise, as more compact the soil is, the less void ratio and more resistant it will be present. The confining pressure tends to increase the resistance of the specimens. The cementing adopted grades showed that the use of different criteria for failure did not significantly alter the stress-strain parameters for the sand studied. The angle of friction values were found within the typical range of medium and compact sands. Cementing acted in the sand providing an intercepted cohesion which increased enhancing the potential cementation. In triaxial compression tests, the sand with void ratio is equal to 0.7 and showed the expected behavior for a compact sand while the stress-strain behavior of the same sand with the void ratio of 0.9 tended to be expected for the soft sand as well

Avaliação do concreto de cimento portland com resíduo da produção de scheelita em substituição ao agregado miúdo

From the 70`s, with the publication of the Manifesto for Environment UN Conference, held in Stockholm, in Sweden (1972), defend and improve the environment became part of our daily lives. Thus, several studies have emerged in several segments in order to reuse the waste. Some examples of waste incorporated in portland cement concrete are: rice husk ash, bagasse ash of cane sugar, powder-stone, microsilica, tire rubber, among others. This research used the residue of the mining industry Scheelite, to evaluate the incorporation of the residue composition of Portland cement concrete, replacing the natural sand. The percentage of residue were incorporated from 0% to 100%, with a variation of 10%, 11 being produced concrete mix in the ratio 1:2:3:0.60, by mass. We evaluated the following characteristics of concrete: slump test, compressive strength, tensile strength by diametral compression, water absorption, porosity and density, based on the ABNT, through tests performed in the Laboratory of Civil Construction, UFRN. The trace with the addition of 60% scheelite residue was obtained which better performance. Therefore, the use of the waste from the production of Scheelite is feasible due to the durability parameters (water absorption and porosity), sustainability, and the good results of the resistance of the concrete

Metodologia de implantação da construção enxuta: estudo de caso em construtora de porte médio

In recent years, the Brazilian construction industry has gone by changes like currency stability, increasing competition, shortage of skilled labor and increasing quality importance required by the customer, who made the sector companies seek solutions through new management practices in order to become more efficient. A alternative to these management practices is known as Lean Construction which is derived from the Toyota System Production. Lean Construction main goals are to reduce parts of activities that do not add value, increase product value by considering customer needs, reduce variability and production cycle time, simplify process by reducing the number of parts or steps, increase the flexibility in the product execution and transparency process, focus the control on overall process, introduce continuous improvement process, maintain a balance between improvements in flows and conversions and seek to learn from practices adopted by competitors. However, the construction industry is characterized by having nomadic activity, which undertakes an unique product with high cost of production and big inertia for behavioral change, making it difficult to implement the philosophy of lean construction in companies. In this sense, the main objective of this study is to develop a methodology for implementation of the principles of Lean Construction. The method of implementing the proposed management system was designed with the aid of 5W2H tool, and the implementation process is divided into three phases. The first one aims to know in a macro way the current operation of construction, identify who is its target audience and what are the products and services offered to the Market. The second phase aims to describe what actions should be taken and which documents are needed to be created or modified; finally, the third step goal consists in how to control and monitor established processes, where through Strategic Planning the company goals would be set along with their respective targets and indicators in order to keep the system working, aiming for continuous improvement with focus on the customer. This methodology was conceived as a case study analyzing a medium size construction with more than 18 years of activity and certified for almost 10 years with ISO9001 and level A in PBQP-H. We also conclude that this implementation process can be used in any developer and / or builder

Desenvolvimento de um sistema de planejamento, gestão de serviços e controle de custos em obras de construção civil

The increasing competitiveness of the construction industry, set in an economic environment in which the offer is now greater than the demand , causes the prices of many products and services, are strongly influenced by the processes of production and the final consumer. Thus, to become more competitive in the market and construction companies are seeking new alternatives to reduce and control costs, production processes and tools that allow for close monitoring of the construction schedule, with the consequent compliance deadline with the client. Based on this scenario, the creation of control tools, service management and planning work emerges as an investment opportunity and an area that can promote great benefits to construction companies. The goal of this work is to present a system of planning, service management and costs control that through worksheets provide information relating to the production phase of the work, allowing the visualization of possible irregularities in the planning and cost of the enterprise, enabling the company to take steps to achieve the goals of the enterprise in question, and correct them when necessary. The developed system has been used in a piece of real estate in Rio Grande do Norte, and the results showed that its use together allowed the construction company to accompany their results and take corrective and preventive actions during the production process, efficiently and effective

Estudo da viabilidade da utilização de cinza de lodo de esgoto como adição em argamassa de cimento Portland

The use of sewage sludge as a raw material falls within the waste recycling key in the current process model environmental sustainability .Waste recycling has been consolidated as a sustainable environmentally sound technical solution, and. Despite showing very variable composition and characteristics, sewage sludge, can be considered as a residue with a high recycling potential in the building sector. In this paper the feasibility of using sewage sludge ash was studied in addition to Portland cement mortar in 1:3 mass considered the standard dash. This gray additions were studied in proportions of 5%, 10 %, 15 %, 20 %, 25% and 30% by mass of cement. The methodology was focused on the characterization of materials by physical, chemical , mechanical , environmental and morphological followed by the production of mortar tests ,and finalized by the characterization tests of mortar in the fresh state, through the consistency index, content of entrained air, bulk density and water retention, and in the hardened state by bulk density, water absorption by capillarity capillarity coefficient, compressive strength, tensile strength in bending ,tensile bond strength and microstructural analysis for percentages of 0 to 20%. After comparing with the standard mortar mortars with addition of ash, it is concluded that the ash of sewage sludge did not impair the integrity and properties of mortars with addition, including increasing resistance to compression and tension, being 20% more indicated percentage. Thus, it becomes feasible the addition of sewage sludge ash in Portland cement mortar for the trait studied

Avaliação do desempenho de uma cortina de estacas espaçadas, atirantada, em areia

It is presented the analysis of a retaining wall designed for the basement of a residential building, located in Natal/RN, which consists in a spaced pile wall, anchored by tiebacks, in sand. This structure was instrumented in order to measure the wall s horizontal movements and the load distribution throughout the anchor fixed length. The horizontal movements were measured with an inclinometer, and the loads in the anchors were measured with strain gages, installed in three places throughout the anchor fixed length. Measurements for displacement were done right after the implementation of each stage of the building and right after the conclusion of the building, and the measurements for loads in the anchors were done during the performance test, at the moment of the locking off and, also, right after the conclusion of the building. From the data of displacement were obtained velocity and acceleration data of wall. It was found that the time elapsed on braced installation was decisive in the magnitude of the displacements. The maximum horizontal displacement of wall ranged between 0,18 and 0,66% of the final depth of excavation. The loads in the anchors strongly reduced to approximately half the anchor fixed length, followed an exponential distribution. Furthermore, it was found that there was a loss of load in the anchors over time, reaching 50% loss in one of them

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

Gestão da cadeia de fornecimento :um estudo em empresas de construção certificadas com a ISO 9000

The aim of this present research is to investigate about aplication of the supply chain management in Civil Construction, through perception of brasilian building companies directors. Research purpose includes potential benefits and main dificults analysis in supply chain management, beyond to identify decision criterions for suppliers and sales chain (commission agent and real state agency) choice and reduction, to facilility management in companies. The methodology used in this work considers the application of a questionnaire with scales of the type Likert being constituted of variables that compose the aspects of evaluation and of behaviors, beyond questions to identify the market profile of the respondents. For analysis statistics is used the descriptive, clusters and variance, ANOVA, analysis last two to verify the connections between variables. The results show more perception as for long terms contracts with suppliers for purchase of materials and services being decisive for companies nowadays (40%) than as for exclusive contracts with commission agents (30%). There is a positive appraisal about viability of hipotetic situations showed, but more caution as for disposition to apply them too. Another results aim for biggers dificults in management of chain links formed by commission agents and real state agencies, than chain links formed by anothers suppliers of materials and services. The companies for study were chosen among to those with ISO 9000 certificate until november 2001, considering that these companies have the best management systems, probably