Wettability/spreading of alkanes at the water-gas interface at elevated temperatures and pressures
Pham, Daniel Thanh-Khac
Master of Science
A model consisting of the Hamaker-Lifshitz theory is used to calculate the spreading transition of alkanes at the water-gas interface. In the current work, the theory is extended to include effects of the temperature and pressure by estimating dielectric polarizability of the vapor and liquid as a function of density through the Clausius-Mosotti equation. The wetting transition temperature of alkane at the water-gas interface increases with increasing of carbon number. The theory is validated by measuring the contact angle of alkane at the water-gas interface by using an interference microscope. Spreading coefficients calculated from contact angles agree with the calculated values. The Hamaker constant calculation, measured contact angle, and measured spreading coefficient show that alkanes approach spreading as the NaCl concentration in water approaches saturation. The theory of this study is also used to predict the flow of sulfur containing sour natural gas in a reservoir, and the calculations are supported by the experimental results.
Chemical engineering; Petroleum engineering