Carbon capture and sequestration (CCS) is an engineering-based approach for mitigating excess anthropogenic CO2 emissions. Deep brine aquifers and basalt reservoirs have shown outstanding performance in CO2 storage based on their global widespread distribution and large storage capacity. Capillary trapping and mineral trapping are the two dominant mechanisms controlling the distribution, migration, and transportation of CO2 in deep brine aquifers and basalt reservoirs. Understanding the behavior of CO2 in a storage reservoir under realistic conditions is important for risk management and storage efficiency improvement. As a result, numerical simulations have been implemented to understand the relationship between fluid properties and multi-phase fluid dynamics. However, the physics-based simulations that focus on the uncertainties of fluid flow dynamics are complicated and computationally expensive. Machine learning method provides immense potential for improving computational efficiency for subsurface simulations, particularly in the context of parametric sensitivity. This work focuses on parametric uncertainty associated with multi-phase fluid dynamics that govern geologic CO2 storage. The effects of this uncertainty are interrogated through ensemble simulation methods that implement both physics-based and machine learning modeling strategies. This dissertation is a culmination of three projects: (1) a parametric analysis of capillary pressure variability effects on CO2 migration, (2) a reactive transport simulation in a basalt fracture system investigating the effects of carbon mineralization on CO2 migration, and (3) a parametric analysis based on machine learning methods of simultaneous effects of capillary pressure and relative permeability on CO2 migration. / Doctor of Philosophy / Carbon capture and sequestration (CCS) has been proposed as a technological approach to mitigate the deleterious effects of anthropogenic CO2 emissions. During CCS, CO2 is captured from power plants and then pumped in deep geologic reservoirs to isolate it from the atmosphere. Deep sedimentary formations and fractured basalt reservoirs are two options for CO2 storage. In sedimentary systems, CO2 is immobilized largely by physical processes, such as capillary and solubility trapping, while in basalt reservoirs, CO2 is transformed into carbonate minerals, thus rendering it fully immobilized. This research focuses on how a large range of capillary pressure variabilities and how CO2-basalt reactions affect CO2 migration. Specifically, the work presented utilizes numerical simulation and machine learning methods to study the relationship between capillary trapping and buoyancy in a sandstone formation, as well as the combined effects of capillary pressure and relative permeability on CO2 migration. In addition, the work also identifies a new reinforcing feedback between mineralization and relative permeability during reactive CO2 flow in a basalt fracture network. In aggregate, the whole of this work presents a new, multi-dimensional perspective on the multi-phase fluid dynamics that govern CCS efficacy in a range of geologic formations.

As the aerospace industry continues to incorporate composites into its aircraft, there will be a need for alternative solutions to the current autoclaving process. Liquid composite molding (LCM) has proven to be a promising alternative, producing parts at faster rates and reduced costs while retaining aerospace grade quality. The most important factor of LCM is controlling the resin flow throughout the fiber reinforcement during infusion, as incomplete filling of fibers is a major quality issue as it results in dry spots or voids. Void formation occurs at the resin flow front due to competition between viscous forces and capillary pressure. The purpose of this work is to characterize capillary pressure in vacuum infusion, and develop a model that can be incorporated into flow simulation. In all tests performed capillary pressure was always higher for the carbon fiber versus fiberglass samples. This is due to the increased fiber packing associated with the carbon fabric. As the fabric samples were compressed to achieve specific fiber volumes an increase in capillary pressure was observed due to the decrease in porosity. Measured values for capillary pressure in the carbon fabric were ~2 kPa, thus the relative effects of Pcap may become significant in flow modeling under certain slow flow conditions in composite processing.

After the injection of CO₂ into a subsurface formation, various storage mechanisms help immobilize the CO₂. Injection strategies that promote the buoyant movement of CO₂ during the post-injection period can increase immobilization by the mechanisms of dissolution and residual phase trapping. In this work, we argue that the heterogeneity intrinsic to sedimentary rocks gives rise to another category of trapping, which we call local capillary trapping. In a heterogeneous storage formation where capillary entry pressure of the rock is correlated with other petrophysical properties, numerous local capillary barriers exist and can trap rising CO₂ below them. The size of barriers depends on the correlation length, i.e., the characteristic size of regions having similar values of capillary entry pressure. This dissertation evaluates the dynamics of the local capillary trapping and its effectiveness to add an element of increased capacity and containment security in carbon storage in heterogeneous permeable media. The overall objective is to obtain the rigorous assessment of the amount and extent of local capillary trapping expected to occur in typical storage formations. A series of detailed numerical simulations are used to quantify the amount of local capillary trapping and to study the effect of local capillary barriers on CO₂ leakage from the storage formation. Also, a research code is developed for finding clusters of local capillary trapping from capillary entry pressure field based on the assumption that in post-injection period the viscous forces are negligible and the process is governed solely by capillary forces. The code is used to make a quantitative assessment of an upper bound for local capillary trapping capacity in heterogeneous domains using the geologic data, which is especially useful for field projects since it is very fast compared to flow simulation. The results show that capillary heterogeneity decreases the threshold capacity for non-leakable storage of CO₂. However, in cases where the injected volume is more than threshold capacity, capillary heterogeneity adds an element of security to the structural seal, regardless of how CO₂ is accumulated under the seal, either by injection or by buoyancy. In other words, ignoring heterogeneity gives the worst-case estimate of the risk. Nevertheless, during a potential leakage through failed seals, a range of CO₂ leakage amounts may occur depending on heterogeneity and the location of the leak. In geologic CO₂ storage in typical saline aquifers, the local capillary trapping can result in large volumes that are sufficiently trapped and immobilized. In fact, this behavior has significant implications for estimates of permanence of storage, for assessments of leakage rates, and for predicting ultimate consequences of leakage. / text

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Orientador: Maria Aparecida Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-08T22:36:24Z (GMT). No. of bitstreams: 1 Miranda_MirladeNazaredoNascimento_D.pdf: 5279700 bytes, checksum: 7d1239d8ea7c570b2b598c0bbd46263b (MD5) Previous issue date: 2007 / Resumo: Sólidos porosos têm sido aplicados em vários setores industriais, principalmente como misturas de diferentes sólidos. A caracterização fisica, bem como a difusividade efetiva desses materiais é importante para a otimização de processos industriais que aplicam o transporte de massa em sólidos porosos. Investigações iniciadas sobre difusividade efetiva em misturas de sólidos indicaram a necessidade de informações sobre a estrutura dos componentes, para se obter um modelo mais adequado. Por isso, este trabalho tem como objetivo detenninar as relações existentes entre as propriedades fisicas dos sólidos puros e de misturas de sólidos e testar um modelo matemático para estimar a difusividade efetiva em sólidos porosos multicomponentes. Foi avaliado o comportamento de misturas dos materiais Zeólita NaY, Alumina, Caulim e Sílica. A difusividade efetiva foi determinada a partir de um modelo que considera a contribuição de cada mecanismo de transferência de massa envolvido em sólidos porosos, considerando as propriedades estruturais do sólido. Essas propriedades são: isotermas de dessorção de água, determinada pelo método estático; área superficial determinada por adsorção de Nitrogênio utilizando o método de cálculo de BET; densidade absoluta determinada por picnometria a gás Hélio; densidade aparente calculada pelo peso e volume do sólido preparado em formato cilíndrico; distribuição do tamanho das partículas determinada por difratometria a laser; distribuição do tamanho dos poros calculada pela equação de Kelvin, a partir dos dados de dessorção de água; porosidade, calculada a partir dos dados de densidade aparente e de densidade absoluta; tortuosidade; permeabilidade intlinseca e relativa. Também foram 'realizados experimentos de secagem para determinar a difusividade efetiva e comparar os resultados com o modelo aplicado. Os resultados obtidos mostram que as isotermas de sorção das misturas seguem uma regra de mistura simples, em função da fração mássica dos componentes. A pressão capilar e a penneabilidade relativa não seguiram a mesma regra, mas apresentaram uma tendência de comportamento de acordo com o material mais microporoso. A difusividade efetiva da água calculada pelo modelo para os materiais puros não concordou completamente com os resultados experimentais, mas a difusividade efetiva de misturas de sólidos apresentou resultados satisfatórios para algumas misturas, principalmente para as misturas quatemárias / Abstract: Porous solids have been applied in several industrial sectors, mainly as mixture of different solids. The physical characterization as well as the effective diffusivity of these materiaIs are important to the optimization of industrial processes that apply mass transport in porous solids. Investigations about effective diffusivity in solid mixture indicated the necessity of infonnation on the structure of the solids in order to obtain a more adequate model. So, the aims of this work were to detennine the relationship between the physical properties of solid mixtures and their single components, and to test the mathematical model to estimate the effective diffusivity in porous solid mixtures. NaY zeolite, Alumina, Kaolin and Silica were the materiaIs evaluated in this work. The effective diffusivity was detennined from the mo deI that considers tn~ contribution of each mass transfer mechanism involved in porous solids, taking into account the structural properties of the solid. The evaluated properties were: water desorption isothenns, detennined by static method; surface area detennined by the data of the Nitrogen adsorption isothenns using BET method; absolute density detennined by Helium gas picnometry; apparent density calculated by weight and volume of the solid prepared in cylinder shape; partic1e size distributions detennined by laser difratometry; pore size distribution calculated by Kelvin equatioh, from the data of water desorption isothenns; porosity, calculated from the data of apparent and absolute density; tortuosity; intrinsic and relative penneability. Drying experiments were also perfonned to detennine the effective diffusivity to compare to the values calculated with the model. The result showed that the desorption isothenns of the mixtures follow: a simple mixture rule, as a function of mass fraction of the components. The capillary pressure and the relative penneability do not follow a mixing rule, but they present a tendency to behave according to the more microporous component. The water effective diffusivity of single solids calculated by the model did nót agree completely with the experimental results, but the water effective diffusivity ofthe solid mixtures presented satisfactory results for some mixtures, mainly for quatemary ones / Doutorado / Engenharia de Processos / Doutor em Engenharia Química

[pt] A formação de emulsões está presente em diversas atividades industriais, incluindo o setor petrolífero. A análise de quebra de gota em capilares com garganta remete ao estudo da formação de emulsões e suas características em meios porosos. Esta dissertação apresenta um modelo numérico baseado nas equações de conservação, e na teoria da lubrificação. O modelo foi desenvolvido considerando as duas fases como fluidos Newtonianos, e o sistema de equações diferencias resultante foi resolvido pelo método de diferenças finitas centrais, implementado em ambiente MATLAB®. Determina-se o campo de pressão dos fluidos, bem como sua interface ao longo do tempo. A análise da influência de parâmetros, tanto da geometria do capilar quanto das propriedades dos fluidos, indicou comportamentos adequados em comparação com os dados disponíveis na literatura. Observou-se que a viscosidade do fluido da fase contínua possui maior influência no tempo de formação de gota, do que a viscosidade do fluido da fase dispersa. O tempo de quebra de gota da fase dispersa varia linearmente com a viscosidade da fase contínua. Observa-se que o raio da garganta do capilar influencia diretamente no tempo de quebra de gota, onde para raios menores, o tempo de formação de gota será menor do que para um raio de garganta maior, devido a um gradiente de pressão capilar mais elevado. / [en] The snap off of emulsion drops appears in several industrial activities, including the oil industry. The analysis snap off in a constricted capillary is related to the study of emulsion formation and its characteristics in a porous media. This thesis presents a numerical model based on the conservation equations and lubrification theory developed for Newtonians fluids. The resulting system of differential equations was solved by finite difference and the code implemented in MATLB®. The analysis of the effect of different parameters, such as the geometry of the capillary and the liquid proprieties, indicated appropriate behaviors in comparison to data in the literature. It was observed that the viscosity of the continuous phase fluid has a stronger influence in the snap off time than the viscosity of the dispersed phase fluid. The snap off time rises with the viscosity of the continuous phase fluid. It was observed that the variation of the radius of the neck directly influences the snap off time, where smaller throat radius leads to shorter snap-off time, due to stronger capillary pressure gradient.

The main water transport properties of clay brick are critically examined in respect of suction and water content. An experimental investigation is carried out to compare the sorptivity and vacuum saturation porosity with suction and “porosity” tests in the standards. The water retaining ability (desorptivity) of freshly mixed hydraulic lime and cement mortars is examined and the effect of hydraulicity, pozzolanic and non-pozzolanic additive materials, binder particle size and the chemistry of mix water on the water retentivity of these mortars are investigated. The inter-relationship of substrate (brick) suction and desorptivity of freshly mixed wet lime and cement mortar are investigated. It is shown that the initial setting time of dewatered freshly-mixed mortars is reduced by a factor of up to 80% and the final setting time is reduced by a factor of 60%. The extent of this reduction depends on hydraulicity. For the cured mortars, following dewatering in the wet state, the compressive and flexural strengths are increased by about 40% for cement mortar and by more than 3 times for lime mortar. The sorptivity of hardened cement and lime mortars is reduced by 80%. These results have implications for the British and European standards where mortars are cast in impermeable steel moulds in which dewatering cannot occur prior to setting. The accuracy of the methodology of the American Petroleum Institute (API) pressure cell technique for testing the water retaining ability of fresh mortars was critically examined. An experimental investigation was carried out in two parts, first by changing the controlled variables of the experimental set up. Second the consequences for the results obtained were evaluated. Experimental verification is undertaken of the fundamental Sharp Front equation S=(2KΨf)^(1/2) which describes the inter-relationship of capillary pressure, sorptivity, porosity and hydraulic conductivity.

Carbon dioxide (CO2) sequestration is one of the most attractive methods to reduce the amount of CO2 in the atmosphere by injecting it into the geological formations. Furthermore, it is also an effective mechanism for enhanced oil recovery. Simulation of CO2 injection based on a suitable modeling is very important for explaining the fluid flow behavior of CO2 in a reservoir. Increasing of CO2 injection may cause a structural deformation of the medium. The structural deformation modeling in carbon sequestration is useful to evaluate the medium stability to avoid CO2 leakage to the atmosphere. Therefore, it is important to include such effect into the model. The purpose of this study is to simulate the CO2 injection in a reservoir. The numerical simulations of two-phase flow in homogeneous and heterogeneous porous media are presented. Also, the effects of gravity and capillary pressure are considered. IMplicit Pressure Explicit Saturation (IMPES) and IMplicit Pressure-Displacements and an Explicit Saturation (IMPDES) schemes are used to solve the problems under consideration. Various numerical examples were simulated and divided into two parts of the study. The numerical results demonstrate the effects of buoyancy and capillary pressure as well as the permeability value and its distribution in the domain. Some conclusions that could be derived from the numerical results are the buoyancy of CO2 is driven by the density difference, the CO2 saturation profile (rate and distribution) are affected by the permeability distribution and its value, and the displacements of the porous medium go to constant values at least six to eight months (on average) after injection. Furthermore, the simulation of CO2 injection provides intuitive knowledge and a better understanding of the fluid flow behavior of CO2 in the subsurface with the deformation effect of the porous medium.

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La modélisation numérique de la migration des hydrocarbures dans les bassins sédimentaires permet de déterminer les accumulations d’hydrocarbures au sein des formations géologiques. A partir de cela on peut prévoir la hauteur d’hydrocarbure piégé. Cette détermination est essentielle dans l’industrie du pétrole. Cependant grâce à certaines études, on a pu s’apercevoir que des erreurs numériques pouvaient apparaître lors de l’utilisation de pression capillaires polynomiales. Dans cette thèse, nous travaillons principalement sur les modèles dits de Darcy et nous évoquons sommairement les modèles de type percolation. L’objectif de ce travail est de fournir de nouveaux modèles des pressions capillaires, donnant de meilleurs résultats que ceux actuellement utilisés. Dans un premier temps, nous décrivons les mécanismes de la migration des hydrocarbures dans les couches. Ensuite nous étudions plus attentivement les lois des pressions capillaires permettant l’écoulement des fluides. Puis nous établissons la discrétisation, suivant la méthode des volumes finis, du problème. Dans la partie suivante nous testons en une dimension de nouveaux modèles de pressions capillaires affines par morceaux. Puis dans une autre partie, nous faisons les tests en deux dimensions de ces modèles auxquels nous rajoutons un autre modèle, bâti à partir des deux précédents. En conclusion, nous synthétisons l’ensemble des résultats et évoquons certaines perspectives concernant l’amélioration des modèles étudiés. / Numerical modeling of hydrocarbon migration in sedimentary basins makes it possible to determine hydrocarbon accumulations within geological formations. From this it is possible to predict the trapped hydrocarbon height. This determination is essential in the petroleum industry. However, thanks to some studies, it has been found that numerical errors can occur when using polynomial capillary pressure. In this thesis, we work mainly on the so-called models of Darcy and we briefly discuss percolation-type models. The objective of this work is to provide new models of capillary pressures, giving better results than those currently used. First, we describe the mechanisms of hydrocarbon migration in the layers. Then we study more closely the laws of capillary pressures allowing the flow of fluids. Then we establish the discretization, according to the finite volume method, of the problem. In the next part we test in one dimension new models of capillary pressures affine in pieces. Then in another part, we do the two-dimensional tests of these models to which we add another model, built from the two previous ones. In conclusion, we summarize all the results and discuss some perspectives concerning the improvement of the studied models.