The improved oil recovery techniques, such as customized ionic composition waterflood or "smart-water" flood, are being developed to increment crude oil production. 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 this work, we identify these flaws in the spontaneous imbibition experiments with mixed-wet limestone samples saturated with crude oil. We describe an improved Amott method and study crude oil recovery from 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 mixed-wet carbonate core samples.
|Original language||English (US)|
|Title of host publication||Day 1 Sun, February 19, 2023|
|State||Published - Mar 7 2023|
Bibliographical noteKAUST Repository Item: Exported on 2023-03-10
Acknowledgements: The authors acknowledge Sirisha Kamireddy, Research Specialist in Ali I. Al-Naimi Petroleum Engineering Research Center (KAUST), for physicochemical analysis of brine solutions and mineral oil, and Samuel D. Fontalvo Guzman, PhD student in Ali I. Al-Naimi Petroleum Engineering Research Center (KAUST), for petrophysical analysis of core plugs. We greatly appreciate and thank SLB Reservoir Laboratory in Dhahran and Joshua Cassidy, Lab Supervisor, for the physicochemical analysis of asphaltenic crude oil and knowledge sharing.