缝合线对碳酸盐岩油气生排运聚的作用

探讨缝合线对碳酸盐岩中油气生成、运移、聚集的意义 .通过碳酸盐岩缝合线分布、形成及有机碳含量与热解参数的分析 ,并结合实际测量缝合线在碳酸盐岩剖面上一般所占的厚度很小 ,并且呈分散状态存在 ,可以生烃 ,也可以排出一部分 ,但由于其生成和排出的量都比较小 ,故很难作为有效的烃源岩 .通常在有明显的缝合线分布的碳酸盐岩地层中 ,其基质中碳酸盐含量很高 ,有机质丰度却很低 ,所以该基质一般也不能作为有效的烃源岩 .通常只有具有一定厚度 ,并且分布较稳定的含泥或泥质碳酸盐岩才可作为良好的烃源岩 .由于缝合线具有较高的孔隙度 ,可作为油气和其它流体运移的通道 .同时 ,溶蚀作用可在缝合线中形成孔洞 ,作为油气聚集的场所 .

Effects of Stylolites on the Generation, Discharge, Migration and Accumulation of Hydrocarbon in Carbonate Rock

The effects were discussed based on the analyses of the generation and distribution of stylolites and the content of the organic carbon in carbonate rock and its pyrolysis parameters. The hydrocarbon generating amount of the stylolites depends on its amount on carbonate rock section. The measured results show that on carbonate rock section, the amount of the stylolites is generally little, and its distribution is dispersive. The stylolites can generate a little of hydrocarbon, and some of the hydrocarbon can discharge, therefore, the stylolites can't become effective hydrocarbon source rock. Generally, in the carbonate rock containing stylolites, the content of carbonate is high and organics is not rich, then the matrix rock can't also become effective hydrocarbon source rock. But the stylolites can be as the migration channels of hydrocarbon and other fluids because of their high porosity, and hydrocarbon can also accumulate in them due to solution cavities.