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Abstract
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Two major challenges in using nanoparticles in enhanced oil recovery (EOR) projects, are high investment costs and environment protection. The objective of this thesis is to investigate the use of low-cost and bio-nanoparticles for EOR. The bio-calcium carbonate nanoparticles were first synthesized from cuttlebone (sepia pharaoins) by ball mill and surfactant methods and then, by producing stable nanofluid, the performance and mechanism of their effectiveness were investigated through contact angle, batch adsorption, and forced imbibition experiments. The results from characterization showed that both methods (ball mill and surfactant) are capable to produce calcium carbonate particles in nano-scale, and bio-nanofluid is stable in the acidic range and at different times. Bio-nanoparticles can alter wettability of rock from oleophilic to oleophobic. This phenomena was due to the presence of chitin in their bio-structure. The adsorption kinetics of bio-nanoparticles onto rock surface follows the pseudo-second-order model and Langmuir adsorption isotherm and the nature of adsorption is as endothermic. Optimal parameters for increasing oil recovery in forced imbibition experiments in water/oil and gas/oil systems in the sand pack include bio-nanofluid with a concentration of 0.05 wt%, normal heptane as phase oil, minimum salinity and ambient temperature and gas flow at 100 cc/min. In the coreflood experiments, the developed model by RSM showed that oil displacement efficiency is strongly influenced by nanofluid concentration, temperature and their interactions, all three parameters (temperature, nanofluid concentration, and salinity) had significant effects on retention of nanoparticles. Reducing the injection rate, increasing the nanofluid concentration and reducing the diameter of the nanoparticles in modeling of nanofluid injection into two phase flow in the prous media would increase oil recovery. Results of this thesis discovered that this bio-nanoparticle as a cos
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