Desorption Mechanism of Asphaltenes in the Presence of Electrolyte and the Extended Derjaguin–Landau–Verwey–Overbeek Theory

Abstract

Desorption of asphaltenes from silica-coated quartz crystals upon exposure to a series of saline solutions was studied through the measurements of quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), and contact angle. Interestingly, it was found that the mass loading and thickness of asphaltene film decreased during the injection of sodium chloride solution at the concentrations ranging from 1 mM to 10 mM, with the surface tending to be hydrophilic; whereas, the mass loading and film thickness increased gradually when the concentration increased from 10 mM to 1000 mM, with the surface inclined to be hydrophobic. It was also found that the electrostatic force had a great effect on this process due to the interactions between the charged interfaces of oil/water and water/solid. Besides, some additional interactions may arise under small distance at the presence of the electrolyte solution, and therefore, a direct force-measuring technique was introduced, in which the functionalized AFM tips felt a solid surface to model the interactions among three phases of oil, water, and solid. Based on the computed results of disjoining pressure isotherms, the theory of Derjaguin-Landau-Verwey-Overbeek (DLVO) was extended, taking into account of the participation of hydration forces which played an important role at short range. These structural forces mostly originated from the overlap of the hydrated layers under a variety of salinity concentrations, resulting in the balance of resultant interactions.

Extended DLVO-based estimates of surface force in low salinity water flooding

“…However, all above mentioned studies have been carried out from core-scale to reservoir-scale. While the atomic force microscopy (AFM) [28,29] and quartz crystal microbalance with dissipation (QCM-D) [30] were used to investigate the effect of water chemistry on adhesion force, few have investigated correlation of nano-scale mechanism(s) of wettability alternation and core-scale experimental results, and fewer have looked beyond the simple and practical approach to guide industry to engineer the injected water chemistry, thus improving oil recovery based on disturbing the in-situ thermodynamic equilibrium. Our objectives were to gain better understanding of low salinity water flooding in nano-scale by addressing the following questions:…”

Response of Non-Polar Oil Component on Low Salinity Effect in Carbonate Reservoirs: Adhesion Force Measurement Using Atomic Force Microscopy

“…Thus, we used a Malvern Zetasizer ZS Nano series to measure the zeta potential of -CH 3 -brine and brine-calcite interfaces at different pH values (6.5, 9.5 and 11). However, the zeta potential experiment methodologies are well demonstrated by Yang et al [58]. It is worth noting that all the measurements were conducted at 27 • C, and the value of each zeta potential was taken from the mean average of four measurements.…”

Wetting Behavior of Tight Rocks: From Core Scale to Pore Scale

“…We assume the values suggested in the literature (Hirasaki, 1991) as 1.5 × 10 10 Pa for A s and 0.05 nm for h s . F S is also calculated for oil (Yang et al, 2015) as…”

“… F S is also calculated for oil (Yang et al, ) as where C 1 and λ 1 are the magnitude and the decay length of short‐range forces for the exponential model, respectively. C 2 and λ 2 are the magnitude and decay length of the long‐range forces, respectively.…”

“…These parameters are evaluated by fitting the experimental data. We assume the values suggested in the literature (Yang et al, ) as 8.86 × 10 7 Pa and 2.87 × 10 6 Pa for C 1 and C 2 , respectively. λ 1 and λ 2 are assumed to be 0.10 and 0.35 nm, respectively.…”