1000 resultados para Botucatu formation
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For many years the silicified sandstone associated of the Botucatu Formation has been the target of interest to researchers and miners, either for understanding the genesis of silicification or for your use as dimension stone and covering on the building industry. If in the first there are several articles available in the geological literature the second there are only technical data marketing available. In the northeast portion of the Paraná State and southwest of the São Paulo State these rocks are mined and traded as covering stones. Not much is known about their intrinsic characteristics and technological properties. To improve the knowledge of the technological behavior of these materials, samples from a quarry from Ribeirao Claro region were petrographically and physically characterized according to the standards established by the Brazilian Association of Technical Standards to dimension stones. Therefore, two bulk samples of silicified sandstone of the Ribeirão Claro/PR region were studied and characterized following the norms established by Brazilian Association of Technical Standards for dimension stones. The results obtained in the petrographical and technological studies are presented and indicated that, in general, the technological performance presented by sandstone studied induces limitations of use as covering materials, mainly horizontally as pavements, door stone and step ladder.
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Pós-graduação em Geociências e Meio Ambiente - IGCE
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Geophysics has been shown to be effective in identifying areas contaminated by waste disposal, contributing to the greater efficiency of soundings programs and the installation of monitoring wells. In the study area, four trenches were constructed with a total volume of about 25,000 m(3). They were almost totally filled with re-refined lubricating oil waste for approximately 25 years. No protection liners were used in the bottoms and laterals of the disposal trenches. The purpose of this work is to evaluate the potential of the resistivity and ground penetrating radar (GPR) methods in characterizing the contamination of this lubricant oil waste disposal area in Ribeiro Preto, SP, situated on the geological domain of the basalt spills of the Serra Geral Formation and the sandstones of the Botucatu Formation. Geophysical results were shown in 2D profiles. The geophysical methods used enabled the identification of geophysical anomalies, which characterized the contamination produced by the trenches filled with lubricant oil waste. Conductive anomalies (smaller than 185 Omega m) immediately below the trenches suggest the action of bacteria in the hydrocarbons, as has been observed in several sites contaminated by hydrocarbons in previously reported cases in the literature. It was also possible to define the geometry of the trenches, as evidenced by the GPR method. Direct sampling (chemical analysis of the soil and the water in the monitoring well) confirmed the contamination. In the soil analysis, low concentrations of several polycyclic aromatic hydrocarbons (PAHs) were found, mainly naphthalene and phenanthrene. In the water samples, an analysis verified contamination of the groundwater by lead (Pb). The geophysical methods used in the investigation provided an excellent tool for environmental characterization in this study of a lubricant oil waste disposal area, and could be applied in the study of similar areas.
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This paper presents the results of a new investigation of the Guarani Aquifer System (SAG) in Sao Paulo state. New data were acquired about sedimentary framework, flow pattern, and hydrogeochemistry. The flow direction in the north of the state is towards the southwest and not towards the west as expected previously. This is linked to the absence of SAG outcrop in the northeast of Sao Paulo state. Both the underlying Piramboia Formation and the overlying Botucatu Formation possess high porosity (18.9% and 19.5%, respectively), which was not modified significantly by diagenetic changes. Investigation of sediments confirmed a zone of chalcedony cement close to the SAG outcrop and a zone of calcite cement in the deep confined zone. The main events in the SAG post-sedimentary history were: (1) adhesion of ferrugineous coatings on grains, (2) infiltration of clays in eodiagenetic stage, (3) regeneration of coatings with formation of smectites, (4) authigenic overgrowth of quartz and K-feldspar in advanced eodiagenetic stage, (5) bitumen cementation of Piramboia Formation in mesodiagenetic stage, (6) cementation by calcite in mesodiagenetic and telodiagenetic stages in Piramboia Formation, (7) formation of secondary porosity by dissolution of unstable minerals after appearance of hydraulic gradient and penetration of the meteoric water caused by the uplift of the Serra do Mar coastal range in the Late Cretaceous, (8) authigenesis of kaolinite and amorphous silica in unconfined zone of the SAG and cation exchange coupled with the dissolution of calcite at the transition between unconfined and confined zone, and (9) authigenesis of analcime in the confined SAG zone. The last two processes are still under operation. The deep zone of the SAG comprises an alkaline pH, Na-HCO(3) groundwater type with old water and enriched delta(13)C values (<-3.9), which evolved from a neutral pH, Ca-HCO(3) groundwater type with young water and depleted delta(13)C values (>-18.8) close to the SAG outcrop. This is consistent with a conceptual geochemical model of the SAG, suggesting dissolution of calcite driven by cation exchange, which occurs at a relatively narrow front recently moving downgradient at much slower rate compared to groundwater flow. More depleted values of delta(18)O in the deep confined zone close to the Parana River compared to values of relative recent recharged water indicate recharge occur during a period of cold climate. The SAG is a ""storage-dominated"" type of aquifer which has to be managed properly to avoid its overexploitation. (C) 2011 Elsevier Ltd. All rights reserved.
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In heavy oil fields there is a great difficulty of the oil to flow from the reservoir to the well, making its production more difficult and with high cost. Most of the original volumes of oil found in the world are considered unrecoverable by the use of the current methods. The injection of micellar solutions has a direct action in the oil interfacial properties, resulting in an enhanced oil recovery. The objective of this research was the study and selection of micellar solutions with ability to decrease the interfacial interactions between fluids and reservoir formation, increasing oil production. The selected micellar solutions were obtained using commercial surfactants and surfactants synthesized in laboratory, based on the intrinsic properties of these molecules, to use in the enhanced oil recovery. Petroleum Reservoirs were simulated using sandstone plugs from Botucatu formation. Experiments with conventional and enhanced oil recovery techniques were accomplished. The obtained results showed that all micellar solutions were able to enhance oil recovery, and the micellar solution prepared with a SB anionic surfactant, at 2% KCl solution, showed the best recovery factor. It was also accomplished an economic analysis with the SB surfactant solution. With the injection of 20% porous volume of micellar solution, followed by brine injection, the increment in petroleum recovery can reach 81% recovery factor in the 3rd porous volume injected. The increment in the total cost by the addition of surfactant to the injection water represents R$ 7.50/ton of injected fluid
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The high concentration of residual oil is one of the greatest problems found in petroleum mature fields. In these reservoirs, different enhanced oil recovery methods (EOR) can be used, highlighting the microemulsion injection. The microemulsion has showed to be efficient in petroleum recovery due to its ability to promote an efficient displacement of the petroleum, acting directly in the residual oil. In this way, this research has as objective the study of microemulsion systems obtained using a commercial surfactant (TP), determining microemulsion thermal stabilities and selecting points inside the pseudoternary phases diagram, evaluating its efficiencies and choosing the best system, that has the following composition: TP as surfactant (S), isopropyl alcohol as co-surfactant (C), kerosene as oil phase, water as aqueous phase, C/S ratio = 1, and 5% sodium p-toluenesulfonate as hydrotope; being observed the following parameters for the selection of the best pseudoternary phases diagram: C/S ratio, co-surfactant nature and addition of hydrotope to the system. The efficiency in petroleum recovery was obtained using two sandstone formation systems: Assu and Botucatu. The study of thermal stabilities showed that as the concentration of active matter in the system increased, the thermal stability also increased. The best thermal stability was obtained using point F (79.56 0C). The system that presented the best recovery percentile between the three selected (3) was composed by: 70% C/S, 2% kerosene and 28% water, with 94% of total recovery efficiency and 60% with microemulsion injection, using the Botucatu formation, that in a general way presented greater efficiencies as compared with the Assu one (81.3% of total recovery efficiency and 38.3% with microemulsion injection)
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This work aims to study the influence of two additives, the monomer, acrylamide and its polymer, polyacrylamide, solubilized in microemulsion systems and applied on enhanced oil recovery. By the microemulsion system obtained, it was chosen points into the phase diagram, presenting these compositions: 25%, 30%, 35% C/T; 2% Fo (fixed for all points) e 73%, 68% e 63% Fa, respectively. However, the monomer and the polymer were solubilized in these microemulsion points with 0.1%; 0.5%; 1% e 2% of concentration, ordering to check the concentration influence at the physicochemical properties (surface tension and rheology) of the microemulsion. Through the salinity study, was possible to observe that the concentrations of 1% and 2% of polymer made the solution became blurred, accordingly, the study of surface tension and rheology only was made for the concentrations of 0.1% e 0.5% of monomer and polymer, respectively. By the surface tension study it was observed that how the concentration of active matter (C/T) was increasing the surface tension was amending for each system, with or without additives. In the rheology study, as it increases the concentration of active matter increases both the viscosity of the microemulsion system (SME) with no additive, as the SME with polymer (AD2). After the entire study, it was chosen the lower point of active matter (25% C/T; 2% Fo e 73% Fa), plus additives in concentrations of 0.1% and 0.5% to be used on enhanced oil recovery. Assays were made on sandstone from Botucatu Formation, where after the tests, it was concluded that among the studied points, the point who showed the best efficiency of advanced shift was the microemulsion system + 0.5% AD2, with a recovery of 28% of oil in place and a total of 96,49%, while the other solution with 0.5% of polymer presented the worst result, with 14.1% of oil in place and 67,39% of efficiency of total displacement
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160 groundwater bores in the Ribeirao Preto region were used to study the behaviour of the piezometric surface of the Botucatu Formation aquifer by geostatistical methodology. The semi-variogram showed the following results: nugget = 50 m2; sill = 450 m2 and range = 4.5 km. The piezometric surface, obtained by punctual kriging in a 100 x 100 knot grid, revealed two lowered zones: one in a southwest to north-northeastern trend, indicating the groundwater flow north toward the Rio Pardo; and the other in the central part due to the high concentration of holes in the urban region of Ribeirao Preto city. -from English summary
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Pós-graduação em Engenharia Mecânica - FEB
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Pós-graduação em Geociências e Meio Ambiente - IGCE
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Geologia Regional - IGCE
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)