Abstract
Summary This work has objective of studying the stability of oil-water emulsion stabilized by surfactant. A series of experimental study was conducted including spontaneous emulsification, emulsion stability assessments, and core flooding test. The emulsion prepared using 2000 ppm AOS, 10000 ppm NaCl, and with oil-water ratio of 1:1 were stable during the period of 72 hours. The buble distributions showed almost homogeniety along the surface promoting its stability. The experimental results revealed that in situ emulsification induced by surfactant injection improved the cumulative oil recovery by 26% relative to the residual oil remaining after conventional secondary water flooding. These findings demonstrate that surfactant injection can substantially enhance oil recovery by promoting the formation of stable in situ emulsions within sandstone reservoirs.