An Experimental Study of Viscous Surfactant Flooding for Enhanced Oil Recovery

This Master Thesis work aims to find a model system combining the positive effects of surfactant and polymer flooding to enhance oil recovery. This report presents the results of 12 core floors performed to enhance recovery of waterflood residual oil. The recovery is enhanced by a visous surfactant flood consistent of one polymer to increase the viscosity, one surfactant for interfacial tension reduction, and one di-alcohol to function as co-surfactant and for salinity control. The chemical treatment that gave the best result, gave an additional oil production normalized on OOIP of 20%, improving the oil recovery from 45 to 66% mostly by the means of mobility control. Pure viscosity floods gave an additional recovery of 12 to 13% of OOIP. Novel technology is used to investigate environmental friendly enhanced oil recovery. A biopolymer made out of microfibrils from wooden material was for the first time ever to my knowledge, attempted used in a core flood to enhance oil recovery. A viscous surfactant tertiary recovery process may help improve oil recoveries from many marginal oil fields or those that face shut-down due to uneconomic operating costs, but still contain significant amounts of oil