Use of biomarkers, porphyrins, and trace elements to assess the origin, maturity, biodegradation, and migration of Alturitas oils in Venezuela

► Alturitas oils derive from one pulse of hydrocarbon generation, migration, and accumulation. ► These oils come from marine organic matter deposited under reducing conditions. ► Oils from the Marcelina (Palaeocene) reservoir under study, have not been biodegraded. ► A secondary oil migration model for the Marcelina crude oil reservoir is shown. ► V, Ni, polar compounds and porphyrins values had been affected by geohromatography.