Dynamic wettability alteration for combined low salinity brine injection and surfactant flooding on silica surface

Abstract

Experimental results of dynamic contact angle measurements of low salinity brine and combined low salinity water and surfactant flooding (LSW-SF) on silica surface are presented in this study. Dynamic contact angle experiments were carried out for four crude oil samples with low salinity brines and combined low salinity and sodium dodecylbenzene sulfonate (SDBS) solutions. Similar measurements with the same ion strength in presence of different cations, Na + and Ca 2+ , for low salinity injections and combined low salinity-SDBS solutions were also carried out to study the change in dynamic contact angles and wetting behavior. The presences of different cations change the initial contact angles in low salinity solution injections and show different dynamic behaviors in presence of different crude oils. The signs and values of the line tension to oil/water interfacial tension ratios have been calculated from the size dependence of the dynamic contact angle measurements on the silica coated quartz crystal microbalance sensors. Analysis indicates positive line tension values for low salinity brine systems and negative values for LSW-SF systems. Injection of surfactant solutions in presence of electrolyte prompts the spreading of the oil droplet over the surface, which is induced by interfacial tension gradient from the top of the oil droplet toward the contact line. The results indicated that spreading time, which is the required time for oil drop to gradually flatten out, is dependent on type of electrolytes and is a function of surface excess concentration of the surfactant.

Experimental and Molecular Dynamics Simulation to Investigate Oil Adsorption and Detachment from Sandstone/Quartz Surface by Low-Salinity Surfactant Brines

“…At minimal interfacial tension, the contact angles are reduced. This behavior aligns with the principles of the Gibbs adsorption isotherm, which describes the relationship between the changes in interfacial tension and alterations in the chemical activity of solution components, including ions in the bulk solution and at the interface, as described by eq 9 ( 94 , 95 ). where dγ is the change in interfacial tension, R presents the universal gas constant, T denotes the absolute temperature, and Γ n and a n stand for the surface excess concentration and the chemical activity of the n th component in the solution, respectively.…”

“…At minimal interfacial tension, the contact angles are reduced. This behavior aligns with the principles of the Gibbs adsorption isotherm, which describes the relationship between the changes in interfacial tension and alterations in the chemical activity of solution components, including ions in the bulk solution and at the interface, as described by eq 9 94,95 .…”

“…where dγ is the change in interfacial tension, R presents the universal gas constant, T denotes the absolute temperature, and Γ n and a n stand for the surface excess concentration and the chemical activity of the nth component in the solution, respectively. 94 The decrease in NaCl concentration causes expansion of the electrical double layer and greater repulsive forces between oil/ brine and rock/brine; this is due to the more negative surface charge created on the rock surface which repels the co-ions associated with low-salinity brine, creating a favorable surface for oil detachment. For higher brine concentrations like in formation water, cations in this brine get attracted to negatively charged sites on the rock surface and negatively charged polar groups at the oil−water interface, which causes electrostatic attraction to occur.…”

Effect of Salinity on Hydroxyapatite Nanoparticles Flooding in Enhanced Oil Recovery: A Mechanistic Study

“…LSWF increases oil recovery through rock/fluid interactions, solution and surface chemistry, and other factors . It is widely accepted that LSWF’s EOR is related to wettability adjustment toward more water-wet conditions, which causes positive capillary forces and boosts microscopic sweep efficiency in heterogeneous pore systems. − …”

Experimental Core Flooding Investigation of New ZnO−γAl2O3 Nanocomposites for Enhanced Oil Recovery in Carbonate Reservoirs

“…After at least 3 h, the CA was extracted from the recorded images . In this experiment, the measurement is based on Young’s formula as follows σ os = σ ws + σ ow 0.25em c os 0.25em θ where σ so is the surface energy between the solid and oil, σ wo is the surface energy between water and oil, σ ws is the surface energy between the solid and water, and θ is CA at the solid/water/oil boundary.…”