Pore scale interaction between matrix and fracture during miscible and immiscible CO2 injection was studied experimentally using visual models. Initially, visualization experiments were conducted on 2-D glass bead packed models by injecting n-heptane (solvent) displacing different kinds of processed oil. The focus was on the displacement patterns and solvent breakthrough controlled by matrix-fracture interaction and the pore scale behaviour of solvent-oil interaction for different fracture and injection conditions (rate, vertical vs. horizontal injection) as well as oil viscosity. Besides the visual investigation, effluent was also analyzed to calculate the solvent cut and oil recovery. Next, the process was modeled numerically using a commercial compositional simulator and the saturation distribution in the matrix was matched to the experimental data. The key parameters in the matching process were the effective diffusion coefficients and the longitudinal and transverse dispersivities. The diffusion coefficients were specified for each fluid and dispersivities were assigned into grid blocks separately for the fracture and the matrix. Finally, glass etched microfluidic models were used to investigate pore scale interaction between the matrix and the fracture. The models were prepared by etching homogeneous and heterogeneous micro scale pore patterns on glass sheets bonded together and then saturated with colored n-decane as the oleic phase. CO2 was injected at miscible and immiscible conditions. The focus was on visual pore scale analysis of miscibility, breakthrough of CO2 and oil/CO2 transfer between the matrix and the fracture under different miscibility, injection rate and wettability conditions. / Petroleum Engineering

No estudo da dinâmica de solutos num meio poroso é de suma importância o conhecimento das propriedades do meio e dos líquidos percolantes, bem como de fatores externos. Um fator externo relevante é a temperatura e, nesse sentido, objetivou-se com o presente trabalho a determinação de parâmetros de transporte dos íons potássio e nitrato para diferentes valores de temperatura em experimentos de deslocamento miscível. Os parâmetros avaliados foram o fator de retardamento (R), o coeficiente de difusão/dispersão (D) e a dispersividade (λ) e as temperaturas utilizadas foram a ambiente (25°C a 28°C), 40°C e 50°C. Os sais utilizados foram nitrato de potássio e cloreto de potássio, preparados em uma solução composta de 50ppm de nitrato e 2000ppm de potássio e o meio poroso um Latossolo Vermelho Amarelo, textura média. Os resultados obtidos permitiram concluir que a temperatura apresentou influência na velocidade da solução no meio poroso e no coeficiente de dispersão. / In the study of solute dynamics in porous media, it is of extreme importance the knowledge of the medium and transporting liquid properties as well as of external factors as temperature. In this sense, the objective of this work was the determination of parameters for potassium and nitrate ions under different temperatures in miscible displacement experiments, in a sandy loam Oxisol. The evaluated parameters were retardation factor (R) difusion/dispersion coefficient (D) and dispersivity (λ), whereas the used temperatures were the prevailing temperature (25°C to 28°C), 40°C and 50°C. The used salts were potassium nitrate and potassium chloride, prepared in a composed solution of 50 ppm of nitrate and 2000 ppm of potassium. From the results, it could be concluded that the temperature showed high influence on soil solution velocity and dispersion coefficient

No estudo da dinâmica de solutos num meio poroso é de suma importância o conhecimento das propriedades do meio e dos líquidos percolantes, bem como de fatores externos. Um fator externo relevante é a temperatura e, nesse sentido, objetivou-se com o presente trabalho a determinação de parâmetros de transporte dos íons potássio e nitrato para diferentes valores de temperatura em experimentos de deslocamento miscível. Os parâmetros avaliados foram o fator de retardamento (R), o coeficiente de difusão/dispersão (D) e a dispersividade (λ) e as temperaturas utilizadas foram a ambiente (25°C a 28°C), 40°C e 50°C. Os sais utilizados foram nitrato de potássio e cloreto de potássio, preparados em uma solução composta de 50ppm de nitrato e 2000ppm de potássio e o meio poroso um Latossolo Vermelho Amarelo, textura média. Os resultados obtidos permitiram concluir que a temperatura apresentou influência na velocidade da solução no meio poroso e no coeficiente de dispersão. / In the study of solute dynamics in porous media, it is of extreme importance the knowledge of the medium and transporting liquid properties as well as of external factors as temperature. In this sense, the objective of this work was the determination of parameters for potassium and nitrate ions under different temperatures in miscible displacement experiments, in a sandy loam Oxisol. The evaluated parameters were retardation factor (R) difusion/dispersion coefficient (D) and dispersivity (λ), whereas the used temperatures were the prevailing temperature (25°C to 28°C), 40°C and 50°C. The used salts were potassium nitrate and potassium chloride, prepared in a composed solution of 50 ppm of nitrate and 2000 ppm of potassium. From the results, it could be concluded that the temperature showed high influence on soil solution velocity and dispersion coefficient

Made available in DSpace on 2015-03-26T13:23:35Z (GMT). No. of bitstreams: 1 texto completo.pdf: 1110634 bytes, checksum: 2fca1d4f36b7153de287bd841f14152d (MD5) Previous issue date: 2011-02-10 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The effectiveness of the mathematical models developed to describe the solute transport in the soil depends on the reliability of the values of the transport parameters. Although the determination of these parameters use the same transport equation, some experimental conditions such as the column length and the pore water velocity does not have standards, making questionable the results and the comparison of different researches. Thus, the aim of this study was to evaluate the influence of flow velocity and the length of soil column to determine the coefficient of dispersion-diffusion (D), dispersivity (λ) and the retardation factor (R) of the potassium ion (K+) on an Oxisol (clay soil) and on a Dystric Quartzarenic Neosol (sandy soil). The experiment was conducted in a laboratory using, for each soil, columns of lengths (L) equals to 10, 20, 30, 40 and 50 cm, with an internal diameter of 47 mm and pore water velocities equal to (v) 61.9, 69.12, 74.88 and 80.86 cm h-1 for the clay soil and 37.16, 40.57, 48.07 and 44.0 cm h-1 for the sandy soil. The columns repacked and saturated with a solution of CaCl2, 0.005 mol L-1 were connected to a Mariotte bottle, containing the same solution of CaCl2, until a steady flow is achieved. Later, it was applied the head that would provide the desired pore water velocity according to the hydraulic conductivity and total porosity of the column, and then the solution was replaced by a KCl solution containing 130 mg L-1 of K+. The effluent of the solution of K+ was collected until seven pore volumes for clay soil and five pore volumes for sandy soil were achieved. These pore volumes were divided into 18 samples of about 0.28 and 0.39 pore volumes for sandy and clay soil, respectively. The R and D transport parameters were obtained using the Disp computer program and the λ was obtained by the equation D = Do + λv, being Do equal to 0.0713 cm2 h-1 for the KCl. For both soils, D increased linearly with L and v and the λ linearly increased with L. The R, for the clay soil, linearly decreased with L and increased with v. For the sandy soil, the R had a linear decreased in terms of L. It can be concluded that the solute transport parameters were influenced by the length of soil column and the pore water velocity. / A eficácia dos modelos matemáticos desenvolvidos para descrever o transporte de solutos no solo depende do grau de confiabilidade dos valores dos parâmetros de transporte. Apesar dos trabalhos de determinação destes parâmetros utilizarem a mesma equação de transporte, algumas condições experimentais como o comprimento da coluna e a velocidade de deslocamento da solução aplicada não têm padronização, tornando questionáveis os resultados obtidos e a comparação destes com outros trabalhos. Com isso, este estudo objetivou avaliar a influência da velocidade de escoamento e do comprimento da coluna de solo na determinação do coeficiente de dispersão-difusão (D), da dispersividade (λ) e do fator de retardamento (R) do íon potássio (K+) em um Latossolo Vermelho distrófico (LVd) e num Neossolo Quartizarênico órtico (RQo). O experimento foi realizado em laboratório, utilizando, para cada solo, colunas de lixiviação de comprimento (L) iguais a 10, 20, 30, 40 e 50 cm, com 4,7 cm de diâmetros internos e velocidades de escoamento da solução (v) de 61,9; 69,12, 74,88 e 80,86 cm h-1 para o LVd e de 37,16; 40,57, 44,0 e 48,07 cm h-1 para o RQo. As colunas, preenchidas com o solo desestruturado e saturado com solução de CaCl2, 0,005 mol L-1, foram conectadas a permeâmetros de carga constante contendo a mesma solução de CaCl2 até se obter escoamento permanente. Posteriormente, aplicava-se a carga que proporcionaria a velocidade desejada de acordo com a condutividade hidráulica da coluna e a porosidade total e, em seguida substituía-se a solução por uma de KCl contendo 130 mg L-1 de K+. O efluente da solução de K+ foi coletado até atingir sete volumes de poros para o LVd e cinco volumes de poros para o RQo, sendo que esses volumes foram divididos em 18 coletas de aproximadamente 0,28 e 0,39 volumes de poros para o RQo e o LVd, respectivamente. Os parâmetros de transporte R e D foram obtidos utilizando-se o programa computacional Disp e a λ foi obtida pela equação D = Do + λv, sendo Do igual a 0,0713 cm2 h-1 para o KCl . Para os dois solos, D apresentou ajuste de regressão linear múltipla positiva em função de L e de v com R² = 0,79 para o LVd e R² = 0,85 para o RQo, o parâmetro λ ajustou-se a regressão linear simples positiva em função de L com R² = 0,92 e R² = 0,93 para o LVd e o RQo, respectivamente. O R, para o LVd, apresentou ajuste de regressão linear simples negativa em função de L (R² = 0,87) e positiva em função de v (R² = 0,68). Para o RQo, o R apresentou ajuste de regressão linear simples negativa em função de L (R² = 0,79). Pode-se concluir que os parâmetros de transporte de solutos foram influenciados pelo comprimento da coluna de solo e pela velocidade de escoamento da solução deslocadora.

L’objet de cette thèse est de développer des méthodologies permettant d’identifier la distribution spatiale des valeurs de perméabilité dans des échantillons de roches. Nous avons tout d’abord développé en laboratoire des expériences d’injection de fluide miscible très visqueux dans des échantillons initialement saturés par une saumure peu visqueuse. Pendant l’injection, l’évolution au cours du temps de la pression différentielle entre les deux faces de l’échantillon a été enregistrée par des capteurs de pression. En outre, des mesures scanner ont fourni une carte 3D de la porosité ainsi que des cartes 3D décrivant la distribution spatiale des concentrations dans l’échantillon à différents temps. Nous avons mis en place une méthode d’interprétation donnant directement le profil 1D de la perméabilité le long de la direction d’écoulement à partir de la pression différentielle mesurée au cours du temps. Cette méthode a été validée numériquement et expérimentalement. Puis, afin d’affiner la description de l’agencement des valeurs de perméabilité dans l’échantillon, c’est à dire d’obtenir un modèle 3D de perméabilité représentatif de l’échantillon, nous avons développé une méthodologie itérative de calage des pressions et des concentrations. Cette méthode passe par deux étapes : une optimisation simple pour capturer l’hétérogénéité dans la direction de l’écoulement et une optimisation complexe pour capturer l’hétérogénéité transverse. Cette méthode a été validée à partir de tests numériques. La méthode a été appliquée à deux des expériences d’injection de fluide visqueux. Nous avons pu alors déterminer des modèles de perméabilité capables de reproduire assez bien les données de pression et de concentration acquises pendant l’injection / The objective of this study is to develop new methodologies to identify the spatial distribution of permeability values inside the heterogeneous core samples. We developed laboratory viscous miscible displacements by injecting high viscosity glycerin into the core samples initially saturated by low viscosity brine. The pressure drop across the samples was measured as a function of time until breakthrough. Meanwhile, CT scan measurements provided a 3D porosity map plus several 3D maps of concentration distribution inside the core samples at different times. A simple permeability mapping technique was developed deducing a one-dimensional permeability profile along the flow direction from the measured pressure drop data. The method was validated with both numerical and laboratory experiments. To go beyond one-dimensional characterization of permeability into cores, we developed an iterative process for matching pressure and concentration data. This method consisted of two steps: a simple optimization for capturing the permeability heterogeneity along the flow direction axis and a complex optimization for capturing transversal permeability heterogeneities. The methodology was validated by numerical data. It was also applied to the data collected from two laboratory viscous miscible displacements. We showed that the final 3D permeability models reproduce well the measured pressure drop and concentration data

Made available in DSpace on 2017-07-10T19:25:01Z (GMT). No. of bitstreams: 1 tatiane_texto.pdf: 2558616 bytes, checksum: c23ff4ce31df2fb07ce669109433709c (MD5) Previous issue date: 2011-08-08 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Swine wastewater application into soil to reuse water on cropping provides the addition of total and dissolved organic matter to soil, which interferes in the dynamics of pesticides in soil. This study aims at evaluating the effects of total and dissolved organic matter application from two systems of swine wastewater, biodigestor and lagoon treatments, in alachlor sorption, desorption, leaching and formation of bound residues into soil. The batch method was used to test sorption and desorption and the results were presented in Freundlich isotherms. The evaluation of miscible displacement of alachlor, in soil treated with total and dissolved organic matter, was performed by disturbed soil columns, by monitoring the concentration of alachlor in leachate, total organic carbon and pH. Extraction and quantification of desorption, extractable and bound residues were carried out. After that, it was registered the chemical fractionation of humic substances in extracts containing organic matter of low molecular weight, humic acids and fulvic acids, which were characterized by infrared spectroscopy and total organic carbon concentration. The swine wastewater addition promoted greater sorption and desorption of alachlor compared to Control. The dissolved organic matter promoted less sorption of alachlor in soil when compared to total organic matter, resulting in an increased leaching of alachlor. The dissolved organic matter did not show desorption residues, only extractable ones. The highest amount of total organic carbon was in organic matter of low molecular weight, spectroscope characterized, by the presence of carboxylate anions, which are important in sorption process. The total organic matter has contributed to the emergence of new sorption sites in soil column and the solids present in its composition blocked the movement of pesticide, resulting in lower leaching of alachlor. The dissolved organic matter interacted with alachlor and / or competed with the sorption sites of soil, promoting greater losses by leaching of this herbicide. / A aplicação de água residuária de suinocultura ao solo como reúso de água na agricultura resulta na adição de matéria orgânica total e dissolvida, que interferem na dinâmica dos pesticidas no solo. Objetivou-se avaliar o efeito da aplicação de matéria orgânica total e dissolvida proveniente de dois sistemas de tratamento de água residuária de suinocultura, biodigestor e esterqueira, na adsorção, dessorção, lixiviação e formação de resíduos ligados de alaclor no solo. O método do equilíbrio foi utilizado para o teste de adsorção e dessorção e os resultados foram apresentados em isotermas de Freundlich. A avaliação do deslocamento miscível do alaclor no solo tratado com matéria orgânica total e dissolvida foi realizada por ensaios em colunas de solo deformado, monitorando-se a concentração de alaclor no lixiviado, teor de carbono orgânico total e pH. Realizou-se a extração e quantificação dos resíduos dessorvíveis, extraíves e ligados do solo. Na sequência, fez-se o fracionamento químico das substâncias húmicas em extratos contendo matéria orgânica de baixo peso molecular, ácidos húmicos e ácidos fúlvicos, que foram caracterizados por espectroscopia infravermelha e pela concentração de carbono orgânico total. A adição de água residuária de suinocultura promoveu maior adsorção e dessorção do alaclor comparado ao Controle. A matéria orgânica dissolvida promoveu menor adsorção de alaclor ao solo comparada à total, resultando em maior lixiviação. A matéria orgânica dissolvida não apresentou resíduos dessorvíveis, apenas extraíveis. A maior quantidade de carbono orgânico total esteve presente na matéria orgânica de baixo peso molecular, caracterizada espectroscopicamente, pela presença de ânions carboxilatos, importantes no processo de adsorção. A matéria orgânica total contribuiu com o surgimento de novos sítios de sorção na coluna de solo e os sólidos presentes em sua composição bloquearam a passagem do pesticida, resultando em menores perdas de alaclor por lixiviação. A matéria orgânica dissolvida interagiu com o alaclor e/ou competiu com os sítios sortivos do solo, promovendo maiores perdas deste herbicida por lixiviação.

Made available in DSpace on 2017-05-12T14:48:22Z (GMT). No. of bitstreams: 1 tatiane_texto.pdf: 2558616 bytes, checksum: c23ff4ce31df2fb07ce669109433709c (MD5) Previous issue date: 2011-08-08 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Swine wastewater application into soil to reuse water on cropping provides the addition of total and dissolved organic matter to soil, which interferes in the dynamics of pesticides in soil. This study aims at evaluating the effects of total and dissolved organic matter application from two systems of swine wastewater, biodigestor and lagoon treatments, in alachlor sorption, desorption, leaching and formation of bound residues into soil. The batch method was used to test sorption and desorption and the results were presented in Freundlich isotherms. The evaluation of miscible displacement of alachlor, in soil treated with total and dissolved organic matter, was performed by disturbed soil columns, by monitoring the concentration of alachlor in leachate, total organic carbon and pH. Extraction and quantification of desorption, extractable and bound residues were carried out. After that, it was registered the chemical fractionation of humic substances in extracts containing organic matter of low molecular weight, humic acids and fulvic acids, which were characterized by infrared spectroscopy and total organic carbon concentration. The swine wastewater addition promoted greater sorption and desorption of alachlor compared to Control. The dissolved organic matter promoted less sorption of alachlor in soil when compared to total organic matter, resulting in an increased leaching of alachlor. The dissolved organic matter did not show desorption residues, only extractable ones. The highest amount of total organic carbon was in organic matter of low molecular weight, spectroscope characterized, by the presence of carboxylate anions, which are important in sorption process. The total organic matter has contributed to the emergence of new sorption sites in soil column and the solids present in its composition blocked the movement of pesticide, resulting in lower leaching of alachlor. The dissolved organic matter interacted with alachlor and / or competed with the sorption sites of soil, promoting greater losses by leaching of this herbicide. / A aplicação de água residuária de suinocultura ao solo como reúso de água na agricultura resulta na adição de matéria orgânica total e dissolvida, que interferem na dinâmica dos pesticidas no solo. Objetivou-se avaliar o efeito da aplicação de matéria orgânica total e dissolvida proveniente de dois sistemas de tratamento de água residuária de suinocultura, biodigestor e esterqueira, na adsorção, dessorção, lixiviação e formação de resíduos ligados de alaclor no solo. O método do equilíbrio foi utilizado para o teste de adsorção e dessorção e os resultados foram apresentados em isotermas de Freundlich. A avaliação do deslocamento miscível do alaclor no solo tratado com matéria orgânica total e dissolvida foi realizada por ensaios em colunas de solo deformado, monitorando-se a concentração de alaclor no lixiviado, teor de carbono orgânico total e pH. Realizou-se a extração e quantificação dos resíduos dessorvíveis, extraíves e ligados do solo. Na sequência, fez-se o fracionamento químico das substâncias húmicas em extratos contendo matéria orgânica de baixo peso molecular, ácidos húmicos e ácidos fúlvicos, que foram caracterizados por espectroscopia infravermelha e pela concentração de carbono orgânico total. A adição de água residuária de suinocultura promoveu maior adsorção e dessorção do alaclor comparado ao Controle. A matéria orgânica dissolvida promoveu menor adsorção de alaclor ao solo comparada à total, resultando em maior lixiviação. A matéria orgânica dissolvida não apresentou resíduos dessorvíveis, apenas extraíveis. A maior quantidade de carbono orgânico total esteve presente na matéria orgânica de baixo peso molecular, caracterizada espectroscopicamente, pela presença de ânions carboxilatos, importantes no processo de adsorção. A matéria orgânica total contribuiu com o surgimento de novos sítios de sorção na coluna de solo e os sólidos presentes em sua composição bloquearam a passagem do pesticida, resultando em menores perdas de alaclor por lixiviação. A matéria orgânica dissolvida interagiu com o alaclor e/ou competiu com os sítios sortivos do solo, promovendo maiores perdas deste herbicida por lixiviação.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-06-13T13:49:19Z No. of bitstreams: 1 GILVANISE ALVES TITO - TESE PPGEA 2009..pdf: 11064945 bytes, checksum: bac5edce5a2a3875418ba29344312d3e (MD5) / Made available in DSpace on 2018-06-13T13:49:19Z (GMT). No. of bitstreams: 1 GILVANISE ALVES TITO - TESE PPGEA 2009..pdf: 11064945 bytes, checksum: bac5edce5a2a3875418ba29344312d3e (MD5) Previous issue date: 2009-09 / A contaminação dos solos por metais pesados tem sido um problema crescente ao meio ambiente e à saúde das pessoas em função da alta toxicidade, razão por que a ciência busca alternativas que possam impedir ou pelo menos minimizar os efeitos poluidores desses metais ou, ainda, remediar os ambientes já contaminados. Assim, vários estudos utilizando matérias adsorventes estão sendo conduzidos como forma de reduzir os efeitos poluidores desses metais. E importante conhecer o processo de adsorção de metais pesados por minerais de argila, uma vez que estes são capazes de imobilizar referidos metais. No presente trabalho avaliou-se, através de três experimentos, a capacidade da bentonita na remediação de solos contaminados com zinco e cobre. O primeiro experimento consistiu no estudo da adsorção desses metais pela bentonita, em pH 4; 5 e 6, utilizando-se os modelos matemáticos de Langmuir e Freundlich. A partir de experimentos tipo "batch" foram elaboradas isotermas de adsorção com quantidades crescentes de zinco e cobre (5; 10; 20; 30; 50; 100; 150 e 200 mg L"1); o segundo experimento consistiu no estudo da mobilidade de zinco e cobre em colunas de lixiviação, preparadas com solo e doses crescentes de bentonita (0; 30 e 60 t ha"1). Os parâmetros de transporte foram calculados através do modelo computacional DISP. No último experimento avaliou-se, em casa de vegetação, o efeito das doses de zinco e cobre (50; 250 e 450 mg kg"1) e de bentonita (0; 30 e 60 t ha"1), adicionados ao solo, na produção de fitomassa e composição mineral do feijoeiro. Terminado o experimento (65 dias), foram determinadas as concentrações do zinco e do cobre nas partes aéreas e nas raízes das plantas e no solo das unidades experimentais, cujos resultados permitiram concluir que a incorporação de bentonita ao solo aumentou a adsorção do zinco e do cobre e que esta adsorção é dependente do pH da solução; que os modelos de Langmuir e Freundlich se apresentaram adequados para descrever a adsorção desses metais; que o tamanho das partículas da bentonita não influenciou na adsorção e a incorporação de bentonita ao solo contribuiu para diminuir a concentração e o acúmulo dos metais zinco e cobre, nas plantas de feijão-macassar. / The contamination of soil by heavy metais has been a growing problem to the environment and to the people's health in function of their toxicity, that has induced the science to search alternatives to prevent, or at least, minimize the pollutant effects of those metais or still, remediate the already polluted environment. Thus, several studies using sorbent materiais are conducted aiming to reduce the pollution problems produced by the excess of heavy metais. It is important to know the process of adsorption of heavy metais by clay minerais, because these are capable to immobilize such metais. The present study was carried out aiming, through three experiments, to evaluate the ability of the bentonite clay on the remediation of soils contaminated with zinc and copper. The fírst experiment consisted in studying the adsorption of these metais by bentonite at pH 4; 5 and 6, using the mathematical models of Langmuir and Freundlich. Adsorption isotherms were elaborated from batch adsorption assays, with increasing zinc and copper concentrations (5; 10; 20; 30; 50; 100; 150 and 200 mg L"1); the second experiment consisted in studying the zinc and copper mobility through leaching columns, prepared with soil and increasing bentonite leveis (0; 30 and 601 ha"1). The transport parameters were calculated using the computer model DISP. Finally, a greenhouse experiment was conducted to evaluate the effects of zinc and copper (50; 250 and 450mg kg"1) and bentonite (0; 30 and 60 t ha"1) added to the soil, on the phytomass production and mineral composition of a bean plant (Vigna unguiculata.h). At the end of the experiment (65 days) the phytomass and the content of zinc and copper in the aerial part, in the roots and in the soil were determined. It was observed that the adsorption of the elements increased with the bentonite application being dependent of the pH of the solution; the two studied models are appropriate to describe the zinc and copper adsorption for the bentonite; the granulometric size of the bentonite does not influence the metais adsorption and that the application of bentonite to the soil contributed to the decrease the concentration and accumulation of the heavy metais in the bean plant.