Examinando por Materia "VISCOSIDAD"
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Artículo de Publicación PeriódicaEvaluation of silicone fluids and resins as CO2 thickeners for enhanced oil recovery using a computational and experimental approach(2021-09) Gallo Jiménez, Gonzalo Augusto; Erdmann, Eleonora; Cavasotto, Claudio N."CO2 thickeners have the potential to be a game changer for enhanced oil recovery, carbon capture utilization and storage, and hydraulic fracturing. Thickener design is challenging due to polymers’ low solubility in supercritical CO2(scCO2) and the difficulty of substantially increasing the viscosity of CO2. In this contribution, we present a framework to design CO2 soluble thickeners, combining calculations using a quantum mechanical solvation model with direct laboratory viscosity testing. The conductor-like polarizable continuum model for solvation free-energy calculations was used to determine functional silicone and silsesquioxane solubilities in scCO2. This method allowed for a fast and efficient identification of CO2-soluble compounds, revealing silsesquioxanes as more CO2-philic than linear polydimethylsiloxane (PDMS), the most efficient non-fluorinated thickener know to date. The rolling ball apparatus was used to measure the viscosity of scCO2 with both PDMS and silicone resins with added silica nanoparticles. Methyl silicone resins were found to be stable and fast to disperse in scCO2 while having a significant thickening effect. They have a larger effect on the solution viscosity than higher-molecular-weight PDMS and are able to thicken CO2 even at high temperatures. Silicone resins are thus shown to be promising scCO2 thickeners, exhibiting enhanced solubility and good rheological properties, while also having a moderate cost and being easily commercially attainable." Artículo de Publicación PeriódicaMechanisms and conditions that affect phase inversion processes. The case of high-impact polystyrene(2019) Maffi, Juan M.; Casis, Natalia; Acuña, Pablo; Morales Balado, Graciela Elizabeth; Estenoz, Diana"The phase inversion during the bulk polymerization of the styrene-polybutadiene system (HIPS manufacturing process) is empirically and theoretically studied in this article. In the experimental work, a series of reactions were performed with benzoyl peroxide as initiator and at temperatures considered of industrial interest (80ºC and 90ºC), varying also the reactor stirring level. Phase inversion was determined by offline viscosity measurements and verified by scanning electron micrography in transmission mode (STEM). The rheological behavior of each reacting system was analyzed and an empirical correlation to predict its apparent viscosity from fundamental reaction parameters was derived. This was achieved successfully for bothbefore and after the phase inversion point." Artículo de Publicación PeriódicaOn the use of espina corona gum as a polymeric additive in water-based drilling fluid(2022-10) Villada, Yurany; Taverna, María Eugenia; Maffi, Juan M.; Giletta, Sebastián; Casis, Natalia; Estenoz, Diana"The aim of this work is to evaluate the espina corona gum (ECG) as a sustainable viscosifier or filtration reducer additive in water-based drilling fluids (WBMs) as a potential replacement of guar gum (GG). ECG is a galactomannan isolated from leguminous seeds of Gleditsia amorphoides, trees that grow in South America with viscosifier properties and applications in the food area. ECG was characterized by FTIR, Z potential, intrinsic viscometry, TGA, and steady and oscillatory shear rheological analysis. Moreover, its effect on the main functional properties of WBMs was studied. Fluids containing bentonite (BT), polyanionic cellulose (PAC), GG or ECG were prepared, and rheological, filtration, thermal and structural properties were determined. In order to study the theoretical rheological behavior, several models such as power law, Sisko and Herschel-Bulkley were evaluated. The rheological studies revealed that WBMs containing ECG exhibit higher viscosities in comparison with those with GG. Herschel-Bulkley parameters indicated that the WBMs with high ECG concentration showed higher yield stress. In addition, the presence of ECG improves the thermal stability and filtration properties. The results indicate that ECG can be considered as an innovative, renewable and non-toxic alternative to partially or totally replace GG in WBMs." Ponencia en CongresoPolymer viscosity: understanding of changes through time in the reservoir and a way to predict them(2019-09) Katz Marquez, Román E.Polymer rheological behavior in an Enhanced Oil Recovery (EOR) project is one of the critical factors to determine whether the polymer injection would be effective to increase the oil production in a field. Due to complications on the measurement of this parameter and its variation within the reservoir, the challenge of understanding viscosity behavior relies on lab and field tests that become key factors to solve this issue. This study was conducted during an injectivity test for an EOR project in Los Perales field (Santa Cruz, Argentina) in three wells with different operational and subsurface conditions, and tests were performed twice a day for 30 days each in order to obtain sufficient time span of data. From lab rheology tests performed at reservoir conditions, where the main objective was to analyze viscosity changes through time, two different tendencies were observed: one that affects in early times and another that becomes preeminent at late times. With these results, a describing equation was developed to predict viscosity evolution over time. The equation consists of three terms including thermal variation, chemical degradation and the final viscosity towards which the polymer tends. Although the equation properly describes both lab and field polymer solution, there is a considerable difference, especially when the effects mentioned become preponderant. This difference is attributed to both the water used for the mixture and the possible impurities that may be incorporated during the maturation or transfer of the polymer. Since most of the data used was obtained from field tests, this emphasizes the appliance of the equation on the field. Impurities turn out to be crucial, specially oxygen (O2) and hydrogen sulfide (H2S) combined. Their presence highly impacts the asymptotic viscosity, so a correlation between H2S content and final viscosity was also developed. Finally, an analysis of the temperature influence on the viscosity was conducted. A correlation between the final viscosity and temperature was found and used to incorporate temperature variations in the predictions and therefore to relate measurements performed at different conditions. The primary advantage of this study is that the equation and correlations enable the prediction of the polymer solution viscosity at any time. This allows the estimation of actual polymer viscosity in the reservoir from a routine measurement at any temperature and impurities content. The versatility of this equation is what makes it novel and useful in an industry going towards EOR projects. Ponencia en CongresoSimulation of viscosity enhanced CO2 nanofluid alternating gas in light oil reservoirs(2017-05) Gallo Jiménez, Gonzalo Augusto; Erdmann, Eleonora"Thickened CO2 nanofluids are a mean to improve volumetric sweep efficiency and gas production in CO2 EOR projects in contrast CO2 flooding. Alternating injection of plain CO2 with thickened CO2 nanofluid is proposed as an economical alternative using the findings of CO2 viscosity enhancement through nanoparticles in current studies. This was achieved by using CMG GEM simulator and contrasting findings with other WAG and CO2 flooding simulations. The simulation was done on a light oil (40 °API) from a Neuquén Basin reservoir. A sensitivity analysis was done to contrast different type of injection schemes. As CO2 nanofluids can be tailor made in order to adjust their viscosity (and other properties like asphaltene deposition control) diverse results were observed. Nanofluids improve the volumetric sweet efficiency, and even low viscosity increment increase the overall gas utilization and conformance compared to CO2 flooding. Since there is no face change, the use of CO2 based nanofluids can be a mean to control CO2 EOR projects avoiding injectivity loss problems. It was observed that injection of mere nanofluid (without alternating CO2) is not technically nor economically convenient as it decreases production rates and has an overall lower economic performance than both WAG and CO2 flooding. Nevertheless, alternating nanofluid with plain CO2 enables higher sweep efficiency while lowering the operational costs due to lower volumes of nanofluid utilized. Adding nanofluid to a WAG scheme also shows improvements in EOR performance."