An investigation was made of the three major phases of shale oil transport history during in-situ retorting (the formation of oil aerosol, the formation of oil film at the raw shale surface, and the release of shale oil from the raw shale surface) to formulate equations which can be used to predict in-situ retorting process performance. Available experimental data were reviewed and used along with theoretical derivations for the formulation of the above equations.