Abstract To investigate the influence of the duration-temperature pairs chosen for laboratory thermal maturations on the evolution of the organic matter (OM) and porosity of the clay-rich source rocks with increasing maturity, long duration (104 days) thermal maturations, bulk, molecular geochemical OM characterization (Rock Eval, GC-TCD, GC/MS) and nitrogen adsorption porosimetry were applied on six type II mudstones from the Kimmeridge Clay formation. These results were compared with shorter duration experiments (72 h) previously carried out. The results show that the increase in the duration of thermal maturation experiments enhanced the degradation of heavy polar OM components into saturated and aromatic hydrocarbons, leading to the production of similar amounts of extractible OM (EOM) enriched in saturated and aromatic hydrocarbons. Then, in preventing the early breaking of low energy bonds, the lower temperature used for the longer duration experiments led to a less pronounced early cracking of OM resulting in a different timing of gas generation. This process did not influence the general evolution of the pore volume, which increased during gas generation. Whatever the duration-temperature pair chosen for maturation experiments highly oil-prone samples formed lower pore volumes during gas generation. Increasing the duration of thermal maturation seemed, nevertheless, to influence the amplitude and the timing of pore alteration events that occur during gas generation, leading to slightly different pore size distributions and pore volumes between short and long duration experiments. However, these differences remain limited, suggesting that results from different time-duration experiments can be easily compared.

中文翻译：

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实验温度和室内封闭热成熟实验时间对富有机质烃源岩孔隙度演化的影响

摘要 为了研究实验室热成熟选择的持续时间-温度对对富粘土烃源岩有机质 (OM) 和孔隙度演化的影响，随着成熟度的增加、长时间（104 天）热成熟、体积、分子地球化学 OM 表征（Rock Eval、GC-TCD、GC/MS）和氮吸附孔隙度测定法应用于来自 Kimmeridge Clay 地层的六块 II 型泥岩。这些结果与之前进行的较短持续时间的实验（72 小时）进行了比较。结果表明，热熟化实验持续时间的增加促进了重极性 OM 组分向饱和烃和芳烃的降解，导致产生相似量的富含饱和烃和芳烃的可提取 OM (EOM)。然后，为了防止低能键的过早断裂，长时间实验所用的较低温度导致 OM 的早期裂解不太明显，从而导致气体产生的时间不同。该过程不影响孔隙体积的总体演变，孔隙体积在气体生成期间增加。无论为成熟实验选择哪种持续时间-温度对，高度易油的样品在气体生成过程中形成的孔隙体积较小。然而，增加热成熟的持续时间似乎会影响气体产生期间发生的孔隙改变事件的幅度和时间，导致短期和长期实验之间的孔径分布和孔隙体积略有不同。然而，这些差异仍然有限，