Origin of the unusually high dibenzothiophene oils in Tazhong-4 Oilfield of Tarim Basin and its implication in deep petroleum exploration

► FT-ICR MS was proved to be powerful in identifying HMW sulfur compounds. ► The relationship between TSR and aromatic sulfur compounds was discussed. ► The high DBT concentrations in Tarim Basin is mainly a result of oil mixing. ► TSR occurred in a deeper interval rather than the present petroliferous horizon.