Separation of macerals in organic-rich source rocks and their geochemical characteristics

Due to the low abundance, poor brittleness and strong lipophilicity of organic matter in source rocks, kerogen enrichment, freezing in liquid nitrogen-thawing at room temperature and adding ethanol to heavy liquid were applied during the separation of macerals in source rocks. The macerals of botryococcus, alginite, cutinite and vitrinite were successfully separated from source rocks in the Luquan area of the Yunnan Province and the Huadian area of the Jilin Province. Rock-Eval, infrared spectroscopy and activation energy analyses indicated that the hydrocarbon generation capacity of the exinite group is strong and the hydrocarbon generation temperature range is narrow. Different macerals have different structures and generation products. Compared with the exinite group, the hydrocarbon generation capacity of vitrinite is lower, the generation temperature range is wider and the products are dominated by gas. There is a negative correlation between maceral density and hydrocarbon generation capacity.