Abstract
Some nanoparticles and fluid dispersants that have the capacity to control migrating fines in formations have been investigated. The primary mechanisms through which fines were trapped and prevented from migrating were electrostatic forces of adsorption of which the pH value of the nanofluids played a significant role. The pH values and zeta potential of the nanofluids, the points of zero charge of the nanofluids and the surface charge density were used to explain the trapping of fines in the presence of some nanoparticles. The likely forces between the nanoparticle compounds and clayey fines that results in trapping and preventing fines migration were also studied. It is speculated that two or more forces of attraction contribute together to trap and prevent fines in sands from further migration.
Results indicate that aluminium oxide nanoparticle has a high capacity to trap fines and prevent them from migrating in sands. The pH value of aluminium oxide in distilled water, brine and ethanol were the lowest, implying that their zeta potentials were high and so contributed to the good performance of the nanoparticles. The high surface charge density of aluminium was also a contributing factor. With distilled water, brine and ethanol, more fines were trapped in the absence of crude oil than in the presence of crude however, in the presence of crude oil, diesel trapped the most fines. These could have occurred mainly as a result of various intermolecular interactions. It was concluded that the pH values of the nanofluids and its related properties work together with electrostatic forces of attraction to trap migrating fines in sands.
