Experimental Study: Anionic-Zwitterionic Surfactant Mixture for Chemical Enhanced Oil Recovery BACHELOR THESIS Michael Arya Yutaka 12218095 Submitted as partial fulfillment of the requirements for the degree of BACHELOR OF ENGINEERING in Petroleum Engineering study program PETROLEUM ENGINEERING STUDY PROGRAM FACULTY OF MINING AND PETROLEUM ENGINEERING INSTITUT TEKNOLOGI BANDUNG 2022 Experimental Study: Anionic-Zwitterionic Surfactant Mixture for Chemical Enhanced Oil Recovery BACHELOR THESIS MICHAEL ARYA YUTAKA 12218095 Submitted as partial fulfillment of the requirements for the degree of BACHELOR OF ENGINEERING in Petroleum Engineering study program Approved by: Thesis Adviser, Prof. Ir. Pudji Permadi, M.Sc., Ph.D. NIP. 195303041980081001 Approved by: Thesis Adviser, Ivan Kurnia, S.T., M.Sc., Ph.D. NIP. 198812052015041004 1 Experimental Study: Anionic-Zwitterionic Surfactant Mixture for Chemical Enhanced Oil Recovery Michael Arya Yutaka*, Pudji Permadi**, and Ivan Kurnia** Copyright 2022, Institut Teknologi Bandung Abstract Surfactant flooding has been known to increase the ultimate recovery factor by reducing interfacial tension (IFT) between water and crude oil. To achieve the expected result, surfactant solution must be selected and formulated properly, usually based on IFT measurement and phase behavior test. Determination of the interfacial tension can be done by using a spinning-drop tensiometer. However, the procedure for using a spinning-drop tensiometer is expensive and time-consuming when it is used to measure IFT at various salinities and various surfactant candidates. Surfactant screening before determining IFT with a spinning-drop tensiometer is one option that can be done because the number of surfactant candidates can be reduced, and the optimum salinity range can be obtained. In this study, there are several types of anionic and zwitterionic surfactant mixtures that will be screened first to see which surfactant mixture is indicated to be the best for IFT measurement using a spinning-drop tensiometer. The selection of the surfactant mixture was carried out based on the aqueous stability test and the phase behavior test. This study aimed to know the performance and the effect of the addition of zwitterionic surfactant into anionic surfactant solution based on an aqueous stability test, phase behavior test, and interfacial tension (IFT) measurement. It was found that the addition of zwitterionic surfactant to anionic surfactant has good synergy and helps in reducing IFT.