Oil industry uses chemicals like methanol and glycols as gas hydrate inhibitors and other chemicals for diverse functions (corrosion, wax, scale inhibitors, antifoamers, emulsion breakers, etc.).
Over the last 10 years, a series of phase equilibrium measurements for well-defined systems (binary and ternary water-glycol-hydrocarbons mixtures) and oil-mixtures (with water and glycols) have been carried out in three PhD projects (of Samer Derawi, Georgios Folas and Muhammad Riaz) funded by Statoil. The measurements were conducted at Statoil’s R&D center at Trondheim. The measurements have been used in the on-going joint-industry project CHIGP for the development and the validation of the CPA equation of state. The focus of the two first aforementioned PhD projects has been well-defined systems, while in the most recent project some oil mixtures have been considered. In parallel, the CPA model has been to a first approximation extended to real oil mixtures using a characterization procedure. The results are satisfactory for the few systems used for validation (due to lack of data), particularly for relatively light (condensate) and non-aromatic oils. Finally, at CERE, during the PhD project of Jose Fonseca, an apparatus for measuring multicomponent multiphase equilibria over extensive T/P ranges has been recently developed.
As basis for further development of the CPA model for calculation of oil in MEG/water and MEG/water in oil (and possibly also for other chemicals of interest), (i) more equilibrium data are necessary for well-defined and for oil mixtures with substantial aromatic and naphthenic content and (ii) a more detailed characterization method should be developed for the CPA model which accounts for the complex interactions, especially at high aromatic content.
Michael Grynnerup Frost
Supervisor: Prof. Georgios Kontogeorgis, gk@kt.dtu.dk
Co-supervisor: Assoc. Prof. Nicolas von Solms, nvs@kt.dtu.dk
Co-supervisor: Prof. Erling H.Stenby, ehst@kemi.dtu.dk