Perpustakaan Digital ITB

Z Field, a giant mature oilfield located in the Central Sumatra Basin which is currently under waterflooding, has been seen declining in production. Detailed EOR screening and study were conducted and confirmed that Alkali Surfactant Polymer (ASP) flooding is ranked high among other EOR methods. The field is divided into several areas, with ASP flooding planned to be implemented in one area to reduce residual oil saturation, and polymer flooding planned for another area to recover oil above its residual saturation. This study aims to examine the effectiveness of ASP flooding implementation using numerical simulation in water-flooded and polymer-flooded areas. Results from both conditions are compared to conclude whether ASP flooding after a polymer flood will still be an effective method to recover oil or even a more effective way. This numerical simulation study uses similar practices with previously implemented successful pilot-scale CEOR projects in Z Field. The starting point is to history match the ASP core flood experiment in the laboratory using a 1D numerical model. A 3D reservoir model is then built by incorporating field data and the upscaled inputs from the core flood model. Results show that ASP flood could enhance oil recovery by up to 72.36% in water-flooded areas and 73.83% in polymer-flooded areas. It was found that polymer flood implementation as early as possible before the ASP flood could increase the oil recovery factor.