Application of Surfactant Solution for Lower Oligocene Formation, White Tiger Field

Abstract

Summary In this study we investigated the possibility of applying a surfactant solution for better oil recovery of the Lower Oligocene formation in the White Tiger Field. The research comprised steps ranging from optimizing the surfactant solution to coreflooding and piloting on two injection wells. The concentrations of surfactants [alkyl ether sulfonate (AES) and sodium α-olefin sulfonate (AOS)] and solvent (n-butanol) were optimized using response surface methodology with the response value set equal to the interfacial tension (IFT). The certified solution was used for conducting coreflooding, and the additional recovery factors from two sample cores were 32% original oil in place (OOIP) and 49% OOIP, respectively. Two injection wells were selected for piloting the injection and were located in White Tiger Field. These wells exhibited strong hydraulic connectivity to seven wells that were under production. The production rates in the observed wells demonstrated a significant increase after 2–3 months of surfactant injection. During the observation period, all seven producer wells showed an increment of approximately 8,475 tons of oil, accounting for approximately 21% of the cumulative oil production.