Scaling up of Surfactant EOR Field Implementation in an Offshore Field Through Optimal Pilot Design

Wettability Alteration from oil-wet to water-wet condition is a very promising EOR technique for producing significant incremental oil recovery from oil-wet tight pores. Surfactant EOR has been widely linked with IFT reduction through continuous surfactant injection for long durations. NOC along with DOW Chemicals developed an alternate Surfactant which induced wettability alteration in oil-wet cores at Lab. This Lab concept was derisked at field level through an injectivity test first (S. Furqan Gilani et al, 2018) and then sequentially scale up via single injector pilot (Neeraj Rohilla et. al, 2022). After the success of the first Pilot involving deeper injection a second pilot was recently completed in a different sub-surface environment involving shallow injection. Second pilot has helped prove permanency of the wettability alteration even after the injection of surfactant has been stopped. Unlike IFT reducing surfactant, wettability altering EOR requires only 9-month long treatment of injector, this tilts the economics related to this EOR to a favorable place and makes it one of the most robust and economical EOR technologies available for an offshore field. After successful implementation of two field trials for an offshore carbonate reservoir, comprehensive studies are being undertaken to scale-up from pilot to field-wide implementation.