Achieving Accurate History Matching in Polymer-Flooded Reservoir Through Advanced Simulation of Polymer Properties

Abstract

Abstract This study aimed at history-matching a full-field numerical model representing a mature oil field that underwent polymer flooding for several years. The main technical challenge was to account for the polymer thermal degradation and the change of polymer molecule that occurred during the development of the field. Accurately representing these changes was crucial for satisfactory oil production history matching. Advanced simulation software was used to simulate all relevant mechanisms, resulting in a successful history matching of the production data. An innovative workflow based on an integrated approach to define geobodies and connections between injectors and producers was implemented to obtain a satisfactory model calibration on the initial water flooding phase. To model the subsequent polymer flooding phase, a single polymer model was not sufficient to accurately represent the impact of polymer injection on oil production rate, in particular towards the end of the historical period. The simulation model was therefore improved using advanced EOR capabilities involving multi-polymer simulation, advanced adsorption model and thermal degradation. Adjusting these properties supported by laboratory data yielded a robust history-match on the whole polymer flooding period.