TY - JOUR EP - 134 SN - 01693913 PB - Springer TI - A Comparative Study of Gas Flooding and Foam-Assisted Chemical Flooding in Bentheimer Sandstones SP - 101 N1 - cited By 22 AV - none VL - 131 UR - https://www.scopus.com/inward/record.uri?eid=2-s2.0-85059583139&doi=10.1007%2fs11242-018-01225-3&partnerID=40&md5=2eb849c64235d598d6ad420120f77e73 A1 - Janssen, M.T.G. A1 - Pilus, R.M. A1 - Zitha, P.L.J. JF - Transport in Porous Media Y1 - 2020/// KW - Alkalinity; Computerized tomography; Enhanced recovery; Floods; Foams; Gases; Injection (oil wells); Sandstone; Secondary recovery; Surface active agents KW - Alkaline; Continuous gas injections; Core flood experiments; Displacement mechanisms; Enhance oil recoveries; Enhanced oil recovery; Immiscible gas injection; Water alternating gas KW - Oil well flooding KW - comparative study; displacement; enhanced oil recovery; fluid injection; foam; immiscible fluid; reservoir flooding; sandstone; surfactant ID - scholars14096 IS - 1 N2 - A laboratory study of principal immiscible gas flooding schemes is reported. Very well-controlled experiments on continuous gas injection, water-alternating-gas (WAG) and alkalineâ??surfactantâ??foam (ASF) flooding were conducted. The merits of WAG and ASF compared to continuous gas injection were examined. The impact of ultra-low oilâ??water (o/w) interfacial tension (IFT), an essential feature of the ASF scheme along with foaming, on oil mobilisation and displacement of residual oil to waterflood was also assessed. Incremental oil recoveries and related displacement mechanisms by ASF and WAG compared to continuous gas injection were investigated by conducting CT-scanned core-flood experiments using n-hexadecane and Bentheimer sandstone cores. Ultimate oil recoveries for WAG and ASF at under-optimum salinity (o/w IFT of 10â??1 mN/m) were found to be similar 60 ± 5% of the oil initially in place (OIIP). However, ultimate oil recovery for ASF at (near-)optimum salinity (o/w IFT of 10â??2 mN/m) reached 74 ± 8% of the OIIP. Results support the idea that WAG increases oil recovery over continuous gas injection by drastically increasing the trapped gas saturation at the end of the first few WAG cycles. ASF flooding was able to enhance oil recovery over WAG by effectively lowering o/w IFT (< 10â??1 mN/m) for oil mobilisation. ASF at (near-)optimum salinity increased clean oil fraction in the production stream over under-optimum salinity ASF. © 2019, Springer Nature B.V. ER -