Surfactant Flooding Performance Between Carbonate Reservoir and Sandstone Reservoir

Abstract

Abstract. High energy consumption must be balanced with an increase in oil reserves. One of them is to increase reserves from existing fields. So far, abundant oil production is still sourced from old or brownfields. This makes many oil companies still make efforts to increase their production on the brownfields. One of these efforts is implementing Enhanced Oil Recovery (EOR), intending to maximize recovery (RF) from the oil field. Enhanced Oil Recovery (EOR) can be categorized as a tertiary production stage to obtain oil in various types of reservoirs, especially heavy oil reservoirs. Around 60% of the world's oil reserves are in carbonate reservoirs, and the rest is sandstone and other lithologies. Therefore, it is crucial to know the characteristics of the reservoir to support the success of the EOR carried out. The stages of tertiary oil production are mainly carried out by chemical means. One widely used method in the field is surfactant injection or surfactant flooding. Surfactant flooding is an EOR method by injecting a surfactant-brine solution into a reservoir filled with oil that the previous step cannot wash away. Of course, surfactant injection carried out in both types of reservoirs will give different results considering the characteristics of each rock. The parameters examined were surfactant adsorption ability by both rocks, alteration of wettability after surfactant was injected, and recovery factor after injection. It was found that the surfactant adsorption on sandstone was low compared to carbonate rock; the wettability alteration was also more effective on sandstone compared to carbonate rock. So that from these two parameters, a higher recovery factor value is obtained in sandstone than carbonate rock reservoir.