湖相与海相碳酸盐岩烃源岩生烃条件对比

根据分布特征、沉积环境、岩石类型、有机地球化学特征和生烃模式等方面的对比，讨论了湖相碳酸盐岩和海相碳酸盐岩两种相同岩性、不同沉积环境烃源岩生烃条件的异同。海相与湖相碳酸盐岩烃源岩，基本上都含有不同量的泥质成分；它们的干酪根类型一般以Ⅰ型或Ⅱ型为主；有机质赋存形式无太大差别，湖相碳酸盐岩烃源岩中可能存在更多的无形态有机质；海相碳酸盐岩有机碳含量普遍较低，而湖相中有机质含量则变化很大；湖相碳酸盐岩烃源岩的生烃模式相比海相研究薄弱，但其二次成烃作用不容忽视。湖相碳酸盐岩烃源岩的形成条件受到较多因素的控制，针对高有机质丰度湖相碳酸盐岩烃源岩形成的生物地球化学及沉积学等方面的研究尤其关键。另外，其晚期生烃可否为湖相深层油气勘探提供充足的烃源仍是未来工作的重要方向之一。

Comparison of hydrocarbon generation conditions between lacustrine and marine carbonate source rocks

The differences of hydrocarbon-generating conditions of lacustrine and marine carbonate source rocks were discussed in various aspects,such as the distribution characteristics,sedimentary environment,rock type,organic geochemical characteristics and hydrocarbon generation mode.The results show that marine and lacustrine carbonate source rocks all containe varying amounts of argillaceous components and are dominated by kerogen of typeⅠor type Ⅱ.In addition,there is no significant difference in occurrence of their organic matter,except for that lacustrine carbonate source rocks contain more amorphous organic matters.Organic carbon content of marine carbonate rocks is generally low,while that of lacustrine carbonate rocks is highly variable.The research of the hydrocarbon generation mode of lacustrine carbonate source rocks is still very weak in comparison with the marine carbonate source rocks,and the secondary hydrocarbon generation of the former should not be neglected.The formation conditions of lacustrine carbonate source rocks are controlled by many factors,the biogeochemical and sedimentological researches of lacustrine carbonate source rocks with high content of organic matters are especially important.Furthermore,the possibility of late hydrocarbon generation of lacustrine source rocks providing sufficient hydrocarbon sources for deep reservoirs of lacustrine faices is one of the important topics for future study.