In this communication, new experimental viscosity measurements at high pressure and high temperature are reported for three binary hydrocarbon systems: methane/heptane, methane/decane and methane/toluene and three multi-component mixtures: a natural gas, a gas condensate and a synthetic volatile oil. The measurements were conducted in a HPHT PVT cell equipped with capillary tube at pressures ranging from 34.5 to 138 MPa and temperature up to 473.15 K.
The experimental data obtained for these mixtures have been used to evaluate the performance of different viscosity models. The investigated viscosity models are the Lohrenz-Bray-Clark (LBC) correlation, the Pedersen correlation and a modified LBC correlation. Although the viscosity models were applied at challenging HPHT conditions, the predictions were in reasonable agreement with experimental results. In general, the Pedersen method showed slightly better viscosity predictions for the mentioned hydrocarbon systems.