Distributions of the alkyl dibenzothiophenes (DBT) are proven as effective proxies for the thermal maturity of bitumen extracts and oils expelled from marine source rocks containing Type II-S kerogen. Here we report on an expanded sample suite and DBT ratios to further refine these relationships. This study investigates the methyldibenzothiophenes (MDBT), dimethyldibenzothiophenes (DMDBT), and trimethyldibenzothiophenes (TMDBT) in 52 source rocks from formations in the United States and the Middle East to substantiate the reliability of these sulfur-bearing compounds to estimate maturity in Type II-S samples. The isomerization of MDBTs, DMDBTs, and TMDBTs shows strong correlations with pyrolysis data (T_max, hydrogen index, and equivalent %VR_o), enabling a direct calculation of thermal maturity from the ratios of the MDBT homologous series. Maturity indicators from biomarkers and other ancillary compounds are also analyzed to highlight the limitations and inconsistencies that can be observed when applying such methods to assess the maturity of Type II-S samples. The derived MDBT, DMDBT, and TMDBT maturity equations provide a reliable assessment of maturity for Type II-S samples, ranging from the immature window to the end of the condensate/wet gas window. Moreover, evaluation of 18 sulfur-rich oils validates the application of MDR maturity equations to fluid samples. Such flexibility allows for inclusive, yet consistent, maturity assessment in sulfur-rich formations when compared to other molecular maturity proxies.

烷基二苯并噻吩 (DBT) 的分布被证明是从含有 II-S 型干酪根的海洋烃源岩中排出的沥青提取物和石油的热成熟度的有效指标。在这里，我们报告了扩展的样本套件和 DBT 比率，以进一步完善这些关系。本研究调查了来自美国和中东地层的 52 种烃源岩中的甲基二苯并噻吩 (MDBT)、二甲基二苯并噻吩 (DMDBT) 和三甲基二苯并噻吩 (TMDBT)，以证实这些含硫化合物在评估 II 型成熟度方面的可靠性。 S 样品。MDBT、DMDBT 和 TMDBT 的异构化与热解数据（T _max、氢指数和当量%VR _o），可以根据 MDBT 同系系列的比率直接计算热成熟度。还分析了生物标志物和其他辅助化合物的成熟度指标，以突出在应用此类方法评估 II-S 型样品的成熟度时可以观察到的局限性和不一致之处。导出的 MDBT、DMDBT 和 TMDBT 成熟度方程为 II-S 型样品的成熟度提供了可靠的评估，范围从未成熟窗口到凝析油/湿气窗口结束。此外，对 18 种富硫油的评估验证了 MDR 成熟度方程在流体样品中的应用。与其他分子成熟度指标相比，这种灵活性允许对富硫地层进行包容且一致的成熟度评估。