Thermodynamic fluid characterization of an Iranian oil reservoir

Abstract

To achieve the best simulation model, fluid thermodynamic modeling and reservoir fluid characterization are basic steps, in which laboratory data should be validated and matched with a proper model. A proper fluid model can avoid expensive PVT experiments. In this paper, a case study is presented using PVT properties of live fluid samples obtained from one of the southwest Iranian oil reservoirs which resulted in a more accurate understanding of the reservoir. The model was used to investigate the effect of different hydrocarbon and non-hydrocarbon gas injection streams into the reservoir. In this paper, PR (Peng-Robinson) equation of state was selected as the best equation to attain the good agreement matching. For splitting the heavy fraction of crude oil, different critical property correlations were studied and the Twu correlation was found to be the best one. Volume shift of C12-C32 and Omega A were more sensitive for matching the experimental data with model. Another sensitive parameter is hydrocarbon interaction coefficient. The average error of CCE tests is 0.013401 and the average error of DL tests is 0.034204 which results in error equal to 0.029003 totally. As a result of this study, an excellent agreement achieved between experimental data and tuned model