Applications of aluminium oxide and zirconium oxide nanoparticles in altering dolomite rock wettability using different dispersing medium

Abstract

Application of nanotechnology in oil and gas industry has received great attention from many researchers. This is due to two features of nanoparticles that make them unique which are their size and the ability to adjust their behaviour. Nanoparticles are very active and energetic materials with a high tendency to form nano textured surfaces in combination with surfactants, and causing a major change in the system's interfacial properties. Surface energy of surfactants can be significantly increased by the interaction of nanoparticle and surfactant and more adsorption on the rock surface occurs with higher surface energy. The objective of this study is to investigate the effectiveness of Al2O3 and ZrO2 nanoparticles to alter oil-wet dolomite rock to more water wet condition. In this study, nanoparticle was dispersed in three different surfactants namely cetyltrimethylammonium bromide, CTAB (cationic), sodium dodecyl sulphate, SDS (anionic) and TX-100 (nonionic). Critical micelle concentration of the surfactant was determined by measuring its surface tension (SF). The CMC value of the surfactant was established at the inflection point of the curve. The IFT was determined after the addition of nanoparticles. The results revealed that there is significant reduction of IFT after addition of nanoparticles. Reduction of IFT indicates the ability of the solution to decrease capillary forces and increase mobility of the oil in pore throat. Initial wettability of the dolomite substrate was determined and then was submerged in different nanofluids at different concentration. Contact angle of the rock surface was measured as quantitative method to determine the wettability of the system. The experiment was further investigated by evaluating adsorption of the surfactant on the rock surface. Isotherm adsorption of the surfactant was studied and the result revealed that ionic surfactant has higher adsorption capacity. This is mainly because the charged group on solid surface strongly influences the adsorption of surfactant at solid-liquid interface.