中上扬子地区二叠系碳酸盐岩烃源岩特征及评价

Characteristics and Evaluation of Permian Carbonate Source Rocks in Middle-Upper Yangtze Region

中上扬子地区烃源岩以海相为主,其中二叠系碳酸盐岩为一套重要的烃源岩层位。通过野外剖面实测和钻井资料,结合岩相古地理特征,查明了该区二叠系碳酸盐岩烃源岩的分布特征,显示其厚度总体较大;通过有机地球化学分析测试表明,该区二叠系碳酸盐岩总体上有机质类型好、有机质丰度较高以及热演化成熟度适中,但在各个层位仍存在一定的差异。综合研究表明,该区二叠系碳酸盐岩烃源岩生烃潜力极大,其中以茅口组和栖霞组最好,吴家坪组次之,长兴组较差。

In the Middle-Upper Yangtze Region,the type of source rock was mainly marine facies,in which the Permian carbonate was an important set of source rocks.By using the measured profiles and drilling data and combined with lithofacies palaeogeographic characteristics,the distribution of the Permian carbonate source rocks was clarified in the area and its thickness was larger in general.Organic geochemical analysis and tests showed that the Permian carbonate source rocks had a good organic matter type with high organic matter abundance and moderate thermal evolution maturity.But there existed a certain difference in each layer.Comprehensive study indicates that the potential of Permian carbonate source rocks is enormous in this area,in which the Maokou Formation and Qixia Formation are the best,Wujiaping Formation takes the second place and Changxing Formation is poor.