New thermodynamic modeling of reservoir crude oil.

Highlights: [•] Asphaltene structures in Yen-Mullins model enable EoS for asphaltene gradients. [•] Flory-Huggins-Zuo EoS predicts asphaltene gradients in oilfield reservoirs. [•] ‘Downhole fluid analysis’ measures fluid gradients in oilfield reservoirs. [•] Oilfield studies show new science and new technology resolve major field issues. [•] Traditional chemical methods corroborate new analyses. [Copyright &y& Elsevier]