Chromatography Effects in Alkali Surfactant Polymer Flooding

Abstract

Abstract Phase experiments were performed to determine an Alkali Surfactant Polymer solution leading to low interfacial tensions for oil produced from the 16 TH reservoir of the Matzen field in Austria. Core flood experiments with the ASP solution were conducted to investigate the incremental oil recovery. Experimental data was history matched utilizing numerical simulation. Results show that at laboratory scale, the various chemicals travel at different speeds owing to the different retardation. Owing to the short distance travelled, the location of the various chemical fronts is close together. Hence, the conditions in the core floods resemble the conditions in the phase experiments. At reservoir scale, however, even after only 0.2 Pore Volumes (PV) injected, a significant separation of the species is seen. Owing to the difference of the reservoir and core scale, chemical compositions need to be used which are leading to sufficient incremental oil for a wide range of compositions. The incremental oil production from ASP flooding can be substantially overestimated if the separation of the chemicals owing to retardation is not accounted for in the design of the chemical flood. In case that pseudo components are used in reservoir simulation, the components should have similar retardation characteristics to ensure that incremental recovery is not overestimated.