I'd first like to thank Dr. Bryant, whom I first met as a sophomore when he taught me how to program in excel. With his guidance I believe I am finally closer to being 90% right 100% of the time. Dr. Huh, for helping me through countless edits of my papers and a calm approach toward research has made my time here that much more enjoyable. I would also like to thank is Dr. Bommer, who advised me to go to graduate school where I became a better engineer; and Glen Baum for not just being a lab supervisor, but being the person I call no matter how badly I screwed up an experiment. You are like a father figure of the petroleum labs who always gets us out of trouble. Lastly, Arletta for being the best advisor I could have, more like a mother away from home. My lab-mate Federico Caldelas, who provided the example for me as an engineer. My lab-mate Nic Huerta for being a great lunch partner and friend, and helping me stumble onto the tests for critical shear rate. I would also like to thank the other members of the nanoparticle group, Tina Zhang, Ki Youl Yoon, and Matt Roberts for your added input on presentations, experiments, and making the meetings exciting with your findings too.

Nanoparticles, when synthesized in a specific size range and with a special surface coating tailored to achieve certain desired functionalities, exhibit unique properties. This is because they are almost of molecular size but still retain many useful colloidal characteristics. Recent developments on novel potential upstream applications of nanoparticles are reviewed with focus on research at our laboratory. Oil-water emulsions and CO2 foams that have long-term stability under harsh downhole conditions could be employed as alternatives to surfactant-stabilized emulsions and foams for drilling and other applications. Nanoparticles that show minimal retention can be employed as sensing-capability carrier to detect fluid and rock properties of the producing zone. For example, paramagnetic nanoparticles delivered to the target formation could evaluate fluids saturations there, with application of magnetic field and measurement of response. Emulsions stabilized with surface-coated silica nanoparticles remain stable for months at high temperatures. By designing the hydrophilic/hydrophobic nature of surface coating, either oil-in-water or water-in-oil emulsions can be generated, with droplet size approaching uniform ~5 micron diameter, and with strongly shear-thinning rheology. Stable foams of supercritical CO2-in-water have been generated by co-injecting CO2 and silica nanoparticle aqueous dispersion through a glass-bead pack. The domain of foam stability and the apparent foam viscosity (which were 10 to 100 times more viscous than CO2) reveals threshold values of critical shear rate, particle concentration and phase ratio. An extensive series of sand-pack column and core-plug flow experiments revealed the mechanisms controlling retention of silica and paramagnetic iron-oxide nanoparticles in porous media. A wide range of particle loadings (0.1~18 wt%) and different rock samples were employed. With proper coating, retention was below 10% of the injected amount even in low permeability rock and with large particle concentrations. Potential for various novel upstream applications of engineered nanoparticles is demonstrated. Introduction Novel nanoscale structured materials, in the form of solid composites, complex fluids, and functional nanoparticle-fluid combinations, are bringing major technological advances in many industries. A few examples are the extraordinary material strength, elasticity and thermal conductivity of nano-based metal and polymer composites; targeted and programmed delivery of drugs and enhanced imaging of human organs in medicine; and chemical/physical properties of nano sensors. These and many other novel advances are due to the orders-of-magnitude increase in interfacial area and associated excess stress and chemical potential for the nano-structured materials; and some chemical and physical properties that are unique to nanoscale. In the petroleum/geosystems engineering discipline, research and applications of nanotechnology have been very limited. This is because subsurface formations have heterogeneity of all length scale and any treatments have to be carried out through boreholes, so that process control is generally difficult with significant uncertainties. And any process application requires a large volume treatment so that the material/process cost has to be small. Despite the difficulties, the current advances in nanotechnology are such that a judicious choice of potential applications, and carrying out focused research to bring those potentials to practical maturity, will result in quantum benefits to the oil and gas industry. The recent surge of interest on nanotechnology applications in upstream oil industry, as evidenced by the search of the SPE literature, shows that the important potential of the nanotechnology is beginning to be recognized.

A variety of sodium alginates, differing in molar mass and structural composition, have been evaluated in the preparation of multi-component microbeads and microcapsules. Bead formation occurred by gelation with calcium chloride. Capsules were produced by reacting the pre-formed beads with the oligocation poly(methylene-co-guanidine). Despite the equiponderous (1:1) mixing with a second polyanion, sodium cellulose sulphate, the influence of the alginate properties remains evident. Specifically, the effect of the chemical composition was found to be more significant than that of the molar mass for both the mechanical and transport properties. Furthermore, for alginates of 73% alpha-l-guluronic acid content less shrinking was observed compared to the 38% guluronic materials. This results in the case of the same encapsulator settings in larger microsphere diameters and thicker membranes accompanied by enhanced mechanical resistance though, also, in a higher permeability for the high-G capsules. However, subsequent coating with lower molar mass alginate allows one to adjust the permeability over a broad range, suitable for cell encapsulation and immunoprotection, without compromising the durability.

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Polymer flooding by liquid polymers is an attractive technology for rapid deployment in remote locations. Liquid polymers are typically oil external emulsions with included surfactant inversion packages to allow for rapid polymer hydration. During polymer injection, a small amount of oil is typically co-injected with the polymer. The accumulation of the emulsion oil near the wellbore during continuous polymer injection will reduce near wellbore permeability. The objective of this paper is to evaluate the long-term effect of liquid polymer use on polymer injectivity. We also present a method to remediate the near well damage induced by the emulsion oil using a remediation surfactant that selectively solubilizes and removes the near wellbore oil accumulation. We evaluated several liquid polymers using a combination of rheology measurement, filtration ratio testing and long-term injection coreflood experiments. The change in polymer injectivity was quantified in surrogate core after multiple pore volumes of liquid polymer injection. Promising polymers were further evaluated in both clean and oil-saturated cores. In addition, phase behavior experiments and corefloods were conducted to develop a surfactant solution to remediate the damage induced by oil accumulation. Permeability reduction due to long term liquid polymer injection was quantified in cores with varying permeabilities. The critical permeability where no damage was observed was identified for promising liquid polymers. A surfactant formulation tailored for one of the liquid polymers improved injectivity three- to five-fold and confirms our hypothesis of permeability reduction due to emulsion oil accumulation. Such information can be used to better select appropriate polymers for EOR in areas where powder polymer use may not be feasible.