Surfactant-Polymer Flooding: Influence of the Injection Scheme.

The use of standard enhanced oil recovery (EOR) techniques allows for the improvement of oilfield performance after waterflooding processes. Chemical EOR methods modify different properties of fluids and/or rock to mobilize the remaining oil. Moreover, combined techniques have been developed to maximize the performance by using the joint properties of the chemical slugs. A new simulator is presented to study a surfactant-polymer flooding, based on a two-phase, five-component system (aqueous and oleous phases with water, petroleum, polymer, surfactant, and salt) for a 2D reservoir model. The physical properties modified by these chemicals are considered as well as the synergy between them. The analysis of the chemical injection strategy is deemed vital for the success of the operations. This plays a major role in the efficiency of the recovery process, including the order and the time gap between each chemical slug injection. As the latter is increased, the flooding tends to behave as two separate processes. Best results are found when both slugs are injected overlapped, with the polymer in first place which improves the sweeping efficiency of the viscous oil. This simulator can be used to study different chemical combinations and their injection procedure to optimize the EOR process.