AUTHOR=Lang Liyuan , Zhao Shuang , Liu Lu 

TITLE=Experimental study of ultra-low IFT foam flooding for low permeability reservoirs

JOURNAL=Frontiers in Energy Research

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2024.1375831

DOI=10.3389/fenrg.2024.1375831

ISSN=2296-598X

ABSTRACT=Foam flooding is an effective oil displacement technique to improve fluid sweep efficiency and increase oil recovery. The objective of this paper is to investigate the applicability of ultra-low IFT foam flooding for low permeability oil recovery under the conditions of WX reservoir block in Tuha oilfield (84℃, 86072mg/L).A modified amphoteric hydroxy sulfobetaine surfactant (Cn-HSB) was formulated as a foaming agent based on the principle of compatibility with crude oil that could achieve the ultra-low interfacial tension (IFT) and strong foamability simultaneously. This is shown to reduce the oil/water dynamic IFT (DIFT) to an ultra-low value of the order of 10 -5 mN/m (0.10wt%), as well as produce a foam volume and half-life of 448mL and 2567s, respectively. In addition, results of IFT and foam quality tests indicate that the modified Cn-HSB has good thermal stability and excellent salinityresistance. Moreover, the ultra-low IFT foam flooding has an ideal injectivity and oil displacement efficiency in low permeability porous media that can mobilize the trapped oil in k=1.50×10 -3 μm 2 with a threshold pressure gradient of 0.115MPa/m. This improves oil displacement efficiency about 15%OOIP.Fundamental knowledge gained from this research gives insight into the application of ultra-low IFT foam flooding in low-permeability reservoirs under a combination of specific reservoir conditions.