Diffusion Coefficients in Systems Related to Reservoir Fluids: Available Data and Evaluation of Correlations

Molecular diffusion determines the time to reach local equilibrium in a reservoir. It can be main production mechanism scenarios such as from fractured reservoirs or tight formation. However, there is lack of high-pressure coefficients for reservoir fluids and its related systems. Many correlations exist, but no consensus on their accuracy these We provide systematic review available data systems fluids, well comprehensive comparison five commonly used hydrocarbon mixtures, including extended Sigmund, Riazi-Whitson, Leahy-Dios-Firoozabadi, Wilke–Chang, Hayduk–Minhas correlations. collected extensive binary mixtures petroleum established database over 80 binaries 1600 points. also gas different oils live are extremely scarce. The were evaluated using database, few selected oil database. None show consistent dominant superiority all although some better particular groups/regions. For composition information often incomplete. Only sets allow between Although trends identified correlation evaluation, conclusive recommendation made model, due scarcity. findings underscore need more accurate measurement modeling that representative at high pressures.