Enhanced nitrogen foams injection for improved oil recovery: from laboratory to field implementation in viscous oil reservoirs offshore Bohai Bay China

Foam injection has been a proven technique for IOR in light oil reservoirs, while for heavy oil reservoirs, enhanced foams are needed. In this study, a polymer enhanced foam system was evaluated via comprehensive laboratory experiments and a field pilot testing. Water flooding has been applied in the targeted oilfield (featured with high oil viscosity and severe heterogeneity), but low recovery factor (< 20%) and high water cut (over 85%) has been observed. The pilot testing of the foam injection indicates that nearly all producers around the injector exhibited good response with incremental oil recovery and the average water cut dropped by 6.3%. The experimental and field pilot data are presented to demonstrate the effectiveness of the enhanced nitrogen foam injection technique, which can be an effective IOR method for the targeted oilfield and other similar viscous oil reservoirs.