Water plays an important role as energy carrier in the solvent-aided thermal recovery processes of heavy oil and bitumen. The effect of water on phase behaviour of bitumen and solvent (light n-alkanes) mixtures is often ignored in thermal reservoir simulation. In this work, the effect of the presence of water on the phase behaviour of solvent in bitumen is studied. The solubility of solvents in bitumen as well as the density and viscosity of the bitumen rich phase are measured in both the presence and the absence of water. Results show a remarkable effect of water on solvent solubility in bitumen especially at high temperature conditions (T > 150 degrees C). A three-phase equilibrium calculation of the water-solvent bitumen ternary system is carried out using a Peng-Robinson equation of state (PR-EoS) coupled with Henry's constant. The results show that the PR-EoS regenerates the ternary system with acceptable accuracy. The density and viscosity of the bitumen rich phase in the presence of water are correlated using the experimental binary data. (C) 2017 Elsevier Ltd. All rights reserved.