Study of Sulfosuccinate and Extended Sulfated Sodium Surfactants on the Malaysian Crude/Water Properties for ASP Application in Limestone

摘要

Among the successful methods in enhanced oil recovery (EOR) is the chemical EOR. The surfactant-based chemical techniquesare highly recommended. However, some drawbacks remained unsolved such as surfactant selection and applicationin the reservoirs. Surfactants are particularly applied in sandstone reservoirs, so paving the path to expand the implementationto limestone reservoirs is required. Recently, alkaline surfactant polymer (ASP) was suggested for limestone reservoirs inMalaysia. However, limited studies discussed the effect of surfactant screening on the process. Thus, this study investigatesthe influence of sulfosuccinate and extended sulfated sodium surfactants in improving ASP performance. The evaluationconsidered the interfacial tension, wettability and recovery factor. The approach used was two-stage experiments of surfactantanalysis and ASP core flooding. The first step used the drop Kruss spinning drop tensiometer, and data physics equipmentdrop shape analyzer to analyze the IFT and the contact angle. The second stage included the limestone sandpack preparationand characterization, followed by ASP flooding. The results showed that single surfactant has low IFT between 0.005 and0.05 mN/m, while significantly, the synergy of surfactant mixtures has ultra-low IFT of 0.0006–0.001 mN/m. The contactangle results showed a drastic alteration of 65–81% reduction. The cationic surfactants achieved complete water-wet on limestone.The sandpack preparation confirmed acceptable uniformity by the histogram identification. The oil recovery provedadditional recovery between 22 and 40%. The results of this research are a step forward to attain the technical feasibility ofASP in limestone reservoirs.