Increasing Reservoir Recovery Efficiency through Laboratory-Proven Hybrid Smart Water-Assisted Foam (SWAF) Flooding in Carbonate Reservoirs

This contribution introduces a new hybrid enhanced oil recovery (EOR) method which combines smart water-assisted foam (SWAF) flooding, known as the SWAF process. The concept of applying flooding in carbonate reservoirs is novel approach previously unexplored literature. synergy effect technique has potential to mitigate number limitations related individual (i.e., conventional water injection and flooding) methods encountered carbonates. In general, rocks are characterized by mixed-wet oil-wet wettability state, contributes poor recovery. Hence, solution been designed produce dual-improvement altering rock towards more water-wet, preconditions reservoir augments stability lamellae, for some conditions favorable relative permeability behavior. Then combined with surfactant (surfactant aqueous or SAS) gas produces effect, leads alteration, interfacial tension (IFT) reduction, thus improves Accordingly, determine optimal an SAS, we conducted series experimental laboratory studies. design divided into three main steps. At first, screening process required so that candidates can be narrowed down our using contact angle tests employ calcite plate Indiana limestone ILS) first filter. Following this, optimum solutions blended different types cationic anionic surfactants create SAS formulations. Subsequently, second performed aim narrow varying gases carbon dioxide, CO2 nitrogen, N2) via test (AST), foamability (FT), (FST). We employed state-of-the-art R5 parameter rapid accurate results place half-life method. most effective combination endorsed core-flooding experiments. this work, two crude oils (Type A B) total acid base numbers (TAN TBN). Results showed greatest changes occurred SW (MgCl2) at 3500 (ppm) both types. demonstrates efficacy alteration carbonates, also supported zeta-potential measurements. concentrations CTAB-based considerably affect up 90% stability). However when presence oil, same solution, reduced from 80%, indicates negative on stability. Moreover, core floods MgCl2-foam mixture (MgCl2 + CTAB AOS provided highest residual factor 92% cumulative original (OIIC). showcases effectiveness proposed reservoirs. Additionally, changing large slug 5 PVs small 2 was producing higher OIIC reducing fluid circulation costs thereby, lowering footprint), making environmentally benign. Thus, it expected under (SW SAS), potentially successful EOR reservoirs, having economic environmental benefits.