Abstract
Emulsification has the potential to profoundly change enhanced oil recovery (EOR) and to improve the mechanism of recovery, and the emulsification performance of the chemical is an important basis for the selection of the injection agent for the surfactant-polymer flooding. The objective of this research is the study of the transportation of the oil-rich zone of surfactant-polymer flooding, its ability to adjust liquid production profile in heterogeneous parallel conglomerate cores at different permeability. A stable water-in-oil emulsion was screened by ultrasonic emulsification experiment with the condition of oil-water ratio at 7:3, the ultrasonic power at 900 W. When the emulsion flowed through the conglomerate core, the blockage of pores by emulsion droplets included the blockage by single droplet and multiple droplets accumulation. A one-dimensional flow characterization model of the water-in-oil emulsion flow was established based on the generalized Darcy's law and corroborated with the single-core emulsion flow experiment. The water-in-oil emulsion had a conformance control when flowed in heterogeneous parallel conglomerate cores. When the pore size of the hyperpermeable layer of the heterogeneous layer is much larger than the size of the emulsion, the fluidity of the emulsion in the hyperpermeable layer would mainly be adjusted with high viscosity, so its adjustment ability is poor. When considering the influence of emulsification on the enhanced oil recovery, it is necessary to fully consider the compatibility of emulsion properties and reservoirs.
NSTL