High Pressure Phase Behavior of Asymmetric Mixtures for Oil Production

Development of a petroleum reservoir requires an accurate description of the phase behavior of the reservoir fluid.

The reservoir fluid phase behavior is used for judgement of the reservoir fluid type, estimation of the gas and oil in-place, determination of the composition, amount, and physical properties of the fluid phases during reservoir production.

Despite the fact that reservoir fluid phase behavior has been studied over decades, there are still some long-standing challenges like phase equilibrium description for gas condensate and volatile systems, density and viscosity description of high pressure and high temperature reservoir fluids, precipitation of wax and asphaltene.

We propose here to study the high pressure phase behavior of asymmetric mixtures related to reservoir fluids. The mixtures cover model systems consisting of components representing light gas components, intermediate components and heavy components in reservoir fluids, and reservoir fluid systems.

The experimental study will provide valuable data for the highly asymmetric systems at high pressure high temperature (HPHT) conditions. The measured data, together with the data collected from the literature, will form the basis for the subsequent modeling study.

For the phase equilibrium modeling, in addition to an investigation of various EoS models, characterization of the ill-defined fractions in the reservoir fluids will be emphasized. For density and compressibility modeling, non-cubic EoS models especially GERG-2008 and the same class of models will be investigated.

For viscosity modeling, the focus will be on the mixing behavior of asymmetric components. The theoretical study in this project is expected to advance the current methodology used in modeling HPHT reservoirs and to provide accurate and practical modeling tools for relevant phase behavior of HPHT reservoir fluids.


Erling Halfdan Stenby
Head of Department, Professor
DTU Chemistry
+45 45 25 20 12