Publications

Chemical injection plans are constantly emerging as a mean to enhance mature oil fields production in Indonesia. The arising challenge, together with those plans is how to optimize CEOR in a situation where operations are governed by extreme price volatility. Through core-flood experiments, the efficacy of a locally-made-surfactant mixed with the polymer has proven to answer the challenge. Three different flooding schemes were analyzed after core-flood experiments at the reservoir temperature (70?) to acquire the finest injection mechanism. Firstly, for scheme A, 0.3% PV of surfactant-polymer was injected after water flooding then soaked; For scheme B, the water-flooded-core with residual oil saturation was injected with the first-phase 0.3% PV of surfactant-polymer then water flooded. Afterward, the second-phase 0.3% PV surfactant-polymer was injected and soaked then followed by chase water injection; Lastly, for scheme C, 0.6% PV of surfactant-polymer was injected and soaked after water flooding. The thermal stability of surfactant-polymer was also monitored as a function of chemical soaking time at reservoir condition. The oil recovery factor and the injected chemical volume are two essential parameters to select the most favorable flooding scheme to recover trapped and bypassed oil. In reference to the experiment, the result shows a high oil recovery factor of 45.16% Sor from scheme B where sequential chemical flooding is the key point that represents chemical soaking time. It also concludes that the addition of chemical volume without adequate soaking time has no significance in increasing oil recovery. This study provides an evident reference to produce oil from �K� Field in Riau economically with the most beneficial injection mechanism. It also highlights the necessity of soaking time in chemical injection along with thermally-stable-surfactant-polymer to be applied in other Indonesian fields.