Prediction of hydrocarbon source rock distribution using logging curves: A case study of Es32 source rock in Nanpu Sag, Huanghua depression, Bohai Bay Basin

The Es-3 is the main hydrocarbon source rock system in the Nanpu Sag. Finally, the TOC and hydrocarbon potential of each sub depression of Es(3)were predicted. The study shows that the hydrocarbon source rocks of Es-3 (2) and Es-3 (4) sections are mainly of type II2 and type II1 respectively, with good organic matter type and high maturity. Biomarker compound parameters indicate that the Es-3 (2) 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 Es-3 (4) 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 & UDelta;lgR method in predicting hydrocarbon source rocks in the Nanpu Sag, and the prediction accuracy is higher; the correlation between TOC and S-1 + S-2 is the best in the model for predicting hydrocarbon potential. The TOC and hydrocarbon potential of the hydrocarbon source rocks in Es-3 (1) are generally low; the high value area of TOC and hydrocarbon potential of the hydrocarbon source rocks in Es-3 (2) 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 Es-3 (4) is mainly concentrated in Shichang sub depression.

Automated summary

The hydrocarbon source rocks in the Nanpu Sag were studied, and it was found that the Es-3 (2) section mainly consists of type II2, while the Es-3 (4) section mainly consists of type II1, with good organic matter type and high maturity. The multiple linear regression method is more effective than the ΔlgR method in predicting hydrocarbon source rocks in this area. The hydrocarbon source rocks in Es-3 (1) have generally low TOC and hydrocarbon potential, while the high value areas of TOC and hydrocarbon potential in Es-3 (4) are mainly concentrated in the Shichang sub depression.