Distributions and Applications of Nitrogen- and Oxygen-Containing Compounds in the Saline Lacustrine Source Rocks of the Baoding–Raoyang Sag, Bohai Bay Basin, Eastern China

βα/αα-tricyclic terpane, which can be used as auxiliary indicators for maturity evaluation and have particular advantages in saline lacustrine source rocks when there is little vitrinite and/or the vitrinite reflectance fails. Oil-source rock correlation of saturated hydrocarbons and nitrogen- and oxygen-containing compounds indicates that the mature first member of the Shahejie Formation at burial depths greater than 3000 m is the major contributor of the low-mature oil in the study area. The hydrocarbon generation model of the saline lacustrine source rocks in the Baoding-Raoyang Sag is thereby re-established, offering important guiding significance for the exploration of low-mature oil in this and analog areas.