There are various types of pores in shale, mainly consisting of nanopores and micropores, causing flow regime variations and apparent permeability cha

The Es₃ is the main hydrocarbon source rock system in the Nanpu Sag. Finally, the TOC and hydrocarbon potential of each sub depression of Es₃were predicted. The study shows that the hydrocarbon source rocks of Es₃² and Es₃⁴ sections are mainly of type II₂ and type II₁ respectively, with good organic matter type and high maturity. Biomarker compound parameters indicate that the Es₃² section hydrocarbon source rocks developed in a semi-saline, low to medium terrestrial source organic matter supplied reduction environment with a high algal contribution; the Es₃⁴ section hydrocarbon source rocks formed in a freshwater, low terrestrial source supplied reduction environment with a medium-high algal contribution. The multiple linear regression method is more effective than the ΔlgR method in predicting hydrocarbon source rocks in the Nanpu Sag, and the prediction accuracy is higher; the correlation between TOC and S₁ + S₂ is the best in the model for predicting hydrocarbon potential. The TOC and hydrocarbon potential of the hydrocarbon source rocks in Es₃¹ are generally low; the high value area of TOC and hydrocarbon potential of the hydrocarbon source rocks in Es₃² is partly between the No. 1 tectonic zone and No. 5 tectonic zone in Linque sub depression, and the TOC and hydrocarbon potential of the hydrocarbon source rocks in Liunan sub depression are larger; the high value area of TOC and hydrocarbon potential of the hydrocarbon source rocks in Es₃⁴ is mainly concentrated in Shichang sub depression.