Study on Influencing Factors of Chemical Flooding for Heavy Oil

Abstract

Alkali and alkali/surfactant displacing agents are designed for two kinds of heavy oil. Results of emulsifying capacity, dynamic interfacial tension (IFT) and water-wet core flooding tests show that, although alkaline/surfactant systems exhibit better capacity in emulsification and IFT reduction, oil recovery values of alkaline/surfactant flooding are lower than those of alkaline flooding. Glass-etched micromodel tests further demonstrate that, when alkaline solution penetrates into the oil phase, water streams break into ganglia coating oil film. Water ganglia may be entrapped by narrow throats, consequently presenting a water-oil alternating slug flow. Similar water ganglia also appears in alkaline/surfactant flooding, however, water channeling along the pore surface occurs subsequently, resulting in its relatively lower oil recovery.

Keywords:

• Alkaline
• displacement mechanism
• microscopic model

Acknowledgments

Financial support by the Fok Ying-Tong393 Education Foundation for Young Teachers in the Higher Education Institutions of China (Grant 114016) and the New Century Excellent Talents Awards Program from the Ministry of Education of China (Grant NECT-07-0846) is gratefully acknowledged.