(262ad) Real-Component Based Molecular Characterization of Petroleum Fluids

As light to medium sweet crude oils keep depleting while demand of oil products are increasing, heavier and sourer crude has become a growing component to global oil market. Accompany with that, extreme bulk properties (including high molecular weights, high boiling points, large densities, high viscosities, etc.) are expected. However, current experimental approaches are still limited in characterizing heavy crudes in two aspects: 1) chemical structures of hydrocarbons with carbon number up to merely 12 can be accurately analyzed; 2) distillation cuts can only be obtained up to 750 K of normal boiling point, even with deep vacuum fractionation apparatus¹. With limited experimental data available, less than 50 wt. % of individual heavy oil or bitumen can be analyzed, which renders simple model extrapolation over the whole crude highly unreliable.

The present work introduces a real-component based molecular characterization method² derived from thermodynamically-consistent correlation of available crude oil data on chemical and physical properties. This method not only gives reasonable predictions for properties of crude oil including heavy cuts, but also provides chemical structures and compositions of model constituent components over the whole crude oil, which serves as a cornerstone of high fidelity refining simulation and molecular management. The results from the molecular characterization of three crude oils including Terengganu (API 73.1), HOOPS Blend (API 34.2), and Cold Lake Bitumen (API 8.1) are presented.

Reference

1. Sánchez-Lemus, M. C., et al. (2016). "Physical properties of heavy oil distillation cuts." Fuel 180: 457-472.

2. Chen, C. C. and H. QUE (2013). "Method of characterizing chemical composition of crude oil for petroleum refinery processing". US Patent 20130185044 A1.