泥页岩中有机质的赋存形态与油气形成

根据不同类型泥页岩镜下微观特征观察，发现泥页岩中的沉积有机质和矿物质主要以"富有机质—矿物聚集体"和"贫有机质—矿物基质体"2种微观组构形态存在。通过泥页岩的生排烃模拟实验研究表明:泥页岩有机质赋存的差异性控制了油气的生成和初次运移过程，由于"富有机质—矿物聚集体"形态组构非均质分布，在不同演化阶段生成、排出及滞留的油气以不同的状态赋存和运移；镜质体反射率（R_o）介于0.6%~1.0%之间，泥页岩层系中滞留的油与富集有机质聚集体呈游离-吸附共轭相态，流动性较差，开采前景较差，R_o介于1.0%~1.3%之间是页岩油开采的有利范围；高演化阶段页岩气资源量的大小受控于泥页岩中富有机质聚集体的含量。基于烃源岩内沉积有机质和无机矿物质微观结构上的非均质性特征，把油气的形成、排出、滞留作为一个统一过程加以认识，将是深入认识页岩油气形成与富集机理的有利手段和重要方法。 

Organic matter occurrence and hydrocarbon generation in shale

The microscopic features of various shales showed that sedimentary organic matter and minerals mainly exist as an "enriched organic matter and mineral aggregation" or "lean organic matter and mineral matrix". The simulations of hydrocarbon generation and expulsion in shale indicated that the difference of organic matter occurrence in shale controlled hydrocarbon generation and primary migration. Due to the heterogeneous distribution of "enriched organic matter and mineral aggregation", the hydrocarbon generated, expelled and preserved at different stages showed different occurrence and migration features. When maturity ranges from 0.6%-1.0% R_o, oil is free or absorbed in the "enriched organic matter and mineral aggregation". Poor liquidity restricts exploration potential. When R_o ranges from 1.0%-1.3%, it is more favorable for shale oil exploration. The content of "enriched organic matter and mineral aggregation" determined the gas potential in shale during the high evolution stage. In view of the heterogeneity of the microstructure of sedimentary organic matter and inorganic minerals in source rocks, the generation, expulsion and retention of oil and gas should be regarded as a united process when exploring for shale gas.