Phase behavior experiments and PVT modeling of DME-brine-crude oil mixtures based on Huron-Vidal mixing rules for EOR applications

Abstract

We present extensive experimental and modeling studies on phase behavior of DME-brine-crude oil mixtures using the Peng–Robinson equation of state (EOS) with the Huron-Vidal mixing rule to capture the interaction between various components of the mixture. We show that DME has strong preference towards the oil phase as compared to the aqueous phase due to its first contact miscibility with hydrocarbons and partial solubility in water/brine. This feature makes DME a potential candidate for enhanced oil recovery (EOR) applications that can lead to accelerated oil production compared to conventional waterflooding technologies. In particular, we present novel experimental data for (i) solubility of DME in brine at various conditions of pressure, temperature and salinity; (ii) phase behavior of a live crude oil; and (iii) partitioning of DME between brine and the live crude oil at reservoir condition. We also develop a PVT model for the DME-brine-oil mixture based on experimental data available from combination of in-house measurements and literature data. Finally, we investigate the predicting capability of the tuned PVT model and determine the effect of feed composition on DME-partitioning coefficients.