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Chemical EOR - High Potential beyond ASP
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, IOR 2017 - 19th European Symposium on Improved Oil Recovery, Apr 2017, Volume 2017, p.1 - 12
Abstract
Chemical enhanced oil recovery methods like alkali-surfactant-polymer (ASP) flooding can yield high additional recoveries at the right conditions. But chemical floods are often cost intensive, and are limited to certain reservoir temperatures, water salinities, and so on. These restrictions reduce the number of reservoirs where chemical floods can be applied with highest performance.
Surfactants are defined and well-known by their ability to lower the interfacial tension (IFT) between oil and water to ultra-low values and thereby mobilize the trapped oil. It is less known that due to their intrinsic properties surfactants and related chemicals can also be used to improve oil recovery via most other EOR techniques. They have the ability to decrease heavy oil viscosity, change reservoir wettability, reduce injection pressure, create stable foams, and increase miscibility. Hence, involving those materials in steam injection, gas/(sc)CO2 injection, solvent flooding, wettability alteration, or foam assisted procedures is an easy way to increase the economics of oil recovery processes even more if the injection facilities are already in place.
This paper describes the physical principles of different EOR techniques and presents examples on how to select the best surfactant for each of the above applications by considering the varying requirements and limitations.