Pore Wetting Phenomena: Implications to Enhanced Oil Recovery and Geologic Carbon Storage

Abstract

Pore wetting has been considered as an important factor in carbon storage and enhanced oil recovery. Previous studies were limited to the wetting measurements on flat substrates; few measurements were directly carried in a pore to indicate the pore wetting. In this paper, we used the pore contact angle measurement technique recently developed in our laboratory to measure the contact angles of fluids in a single capillary, by considering the effects of pore size, applied pressure and temperature and three different CO2 phases (gas, liquid and supercritical). The results indicate that the pore wetting only significantly changes on the CO2 phase transition boundary and then remains unchanged. The effects of pressure and temperature are not significant on the pore wetting when there is no CO2 phase variation. Our data conclude that the pore wetting of liquid in presence of CO2 is in the order of θgasCO2<θsupercriticaCO2<θliquiCO2. The pore wetting varies with glass pore size and applied liquid. The contact angles measured in a glass pore are significantly different from the ones measured on a flat glass substrate.