Investigation on Interfacial Interactions among Crude Oil–Brine–Sandstone Rock–CO₂ by Contact Angle Measurements

Abstract

Wettability plays a crucial role on the performance of enhancing oil recovery techniques because of its effect on fluid saturations and flow behavior in porous medium. This study is directed toward determining contact angles (i.e., wettability) in systems with carbon dioxide, brine, and an oil-saturated rock system. Two situations are considered: Rock system I is partially water-wet, whereas rock system II is effectively oil-wet. Contact angles have been determined experimentally as a function of brine salinity and pressure using the pendant-drop shape analysis. The experiments were carried out at a constant temperature of 318 K and pressures varying between 0.1 up to 16.0 MPa in a pendant-drop cell. For rock system I, the partially water-wet substrate, brine, and CO 2 system, the dependence on the pressure at constant salinity is very small. For this system, at a constant pressure, the contact angle decreases for increasing brine salinity. The results show that the carbon dioxide is the nonwetting phase in the pressure and salinity range studied. This behavior can be quantitatively understood in terms of the expected dependencies of the three interfacial tensions (IFTs) in Young's equation on pressure and brine salinity. For rock system II, the effectively oil-wet substrate, brine, and CO 2 system, the dependency of contact angle on pressure is considerable. This study proves that carbon dioxide becomes the wetting phase at pressures higher than 10.0 MPa. Beyond 10.0 MPa (i.e., in the supercritical region), the contact angle remains practically constant. The effect of salinity on the contact angle of the oil-wet rock system II is small. The behavior can again be quantitatively understood based on expected trends of the three IFTs that determine the contact angle. It is also shown that use of the equation of state method makes it possible to approach the experimental data quantitatively. We conclude that contact angle measurements form an essential ingredient to determine the efficiency of carbon dioxide flooding and storage.

Investigation of Rock Wettability Alteration by Carbonated Water through Contact Angle Measurements

“…Furthermore, wettability alteration by CO 2 dissolution in brine has already been investigated for the systems of CO 2 -water-coal 9-11 , CO 2 -brine-Mica 12, 13 , CO 2 -brine-Quartz 12, 14 , CO 2reservoir brine-reservoir rock [15][16][17][18] and CO 2 -water-glass 19,20 ; however, very limited study focus on the wettability alteration of oil-brine-rock system with dissolution of CO 2 21 . Grape et al 22 performed imbibition tests involving CO 2 -enriched water (carbonated water).…”

Molecular Dynamics Characterizations of the Supercritical CO2–Mediated Hexane–Brine Interface

“…It has been found that CO 2 -EOR and successful CO 2 sequestration are largely controlled by the interfacial characteristics among the injected CO 2 , the reservoir crude oil, the brine and the rock. [6][7][8][9] The interfacial tension (IFT) under high pressure directly relates to the capillary pressure, the maximum storage height of CO 2 , and the flow behaviors in porous media. [9][10][11] If the reservoir pressure is higher than the minimum miscibility pressure (MMP), CO 2 and oil become completely miscible 12 and they contact with brine together at the interface.…”

Study of Shale Wettability for CO2 Storage

“…IFEMA Madrid, Spain, 1-4 June 2015 1-4 June 2015 | IFEMA Madrid the measurements (Ameri et al 2013, Shojai Kaveh et al 2014. When the aqueous phase is not completely saturated with CO 2 , the injectivity and the gas distribution in the reservoir are not only influenced by the rock properties but also by the diffusion of CO 2 into the aqueous phase (Shojai Kaveh et al 2011, Shojai Kaveh et al 2012).…”