Overcoming Challenges of Polymer Injection Pilot in High-viscosity, High-salinity Reservoir – A Case Study from Sirikit Oilfield, Thailand

Abstract

In Pru Kratium (PKM) highly viscous oil reservoir, the secondary recovery method such as waterflood can adversely affect production due to an unfavorable mobility ratio, resulting in viscous fingering and early water breakthrough. Although polymer flooding which usually mitigates unfavorable mobility ratio, this technique also faces a challenge due to the high salinity formation water which may lead to excessive polymer consumption. To improve recovery, a special polymer injection scheme was designed and the small-scale pilot was initiated. After one year of injection, the pilot demonstrated that the polymer improved the sweep efficiency of the flood in both vertical and horizontal directions. Ultimately, the increase in oil recovery factor gain was 2.41%.