At best, more than 50% of crude oil is remaining in the oil field formations after primary production and secondary recovery by waterflood. With the increasing global demand for crude oil, variety of improved oil recovery  (IOR) techniques, such as chemical flooding, thermal recovery by steam injection and miscible displacement by carbon dioxide flooding, are being intensively developed and studied in laboratories. Low/modified-salinity waterflood, frequently called in the literature "smart-water" flood, is a cost-competitive and relatively environmentally-benign IOR technique that aims to increment oil production by altering wetting properties of the rock and enhancing spontaneous imbibition of the injected brine. Counter-current spontaneous imbibition of brine into oil-saturated rock is a critical mechanism of recovery of the crude oil bypassed in highly-heterogeneous carbonate rocks. In laboratory, spontaneous imbibition in the Amott cell experiment is the main instrument to explore oil recovery from oil-saturated core plugs at different wettability conditions. The classical Amott test, however, masks a number of flaws that hinder interpretation of the physical phenomena in recovery dynamics and precise modeling of the cumulative recovery profiles. In our wor, we identify these flaws in the spontaneous imbibition experiments with water-wet and mixed-wet limestone samples saturated with mineral and crude oils. We describe an improved Amott method and study crude oil recovery from water-wet and mixed-wet carbonate core plugs. The introduced modifications of the Amott test ensure reliable and reproducible results for both non-wetting mineral and crude oils. Finally, we show that the resulted smooth recovery profiles of oil production can be described with a mathematical model with high accuracy. For the first time, we show that generalized extreme value (GEV) distribution can be applied to model cumulative oil production from water-wet and mixed-wet carbonate core samples. 

Zoom Meeting ID: 390 863 5638
http://kaust.zoom.us/j/3908635638