Microscale Interactions of Surfactant and Polymer Chemicals at Crude Oil-Water Interface for Enhanced Oil Recovery

摘要

The conventional experimental techniques used for performance evaluation of enhanced oil recovery (EOR) chemicals, such as polymers and surfactants, have been mostly limited to bulk viscosity, phase behavior/ interfacial tension, and thermal stability measurements. Furthermore, fundamental studies exploring the different microscale interactions instigated by the EOR chemicals at the crude oil-water interface are scanty. The objective of this experimental study is to fill this existing knowledge gap and deliver an important understanding on underlying interfacial sciences and their potential implications for oil recovery in chemical EOR. Different microscale interactions of EOR chemicals, at crude oil-water interface, were studied by using a suite of experimental techniques including interfacial shear rheometer, Langmuir trough, and coalescence time measurement apparatus at both ambient (23°C) and elevated (70°C) temperatures. The reservoir crude oil and high salinity injection water (57,000 ppm TDS) were used. Two chemicals, a nonionic surfactant (at 1000 ppm) and a sulfonated polyacrylamide polymer (at 500 ppm and 700 ppm), were chosen since they are tolerant to high salinity and high temperature conditions. Interfacial viscous and elastic moduli (viscoelasticity), interface pressures, interface compression energies, and coalescence time between crude oil droplets are the major experimental data measured.