Improved polymer flooding due to wettability modification

摘要

In this paper wettability modification effects due to polymer injection are presented. Laboratory experiments on a mixed-wet reservoir have shown that the system becomes more water-wet thereby reducing the relative permeability to water much more than to oil. A reduction of one order of magnitude in the end point for water has been measured when a 2000-ppm polymer concentration is injected. The result of such effect is a more favourable mobility ratio, improved sweep efficiency and higher ultimate recovery. Simulation studies have shown that, on the reservoir under consideration, ultimate recovery increases by 90% when a 2000-ppm polymer concentration is injected and by 120% when wettability modification effects also occur.