碎屑岩成油组合的成岩作用研究

STUDY ON THE DIAGENESIS OF CLASTIC OIL FORMATION ASSEMBLAGE

朱家祥 李淑贞

Zhu Jiaxiang Li Shuzhen

同济大学海洋地质系

Marine Geology Department, Tongji University

苏北高邮凹陷下第三系戴一段岩系可以划分出低、中、高三个演化带。其中,中演化带位于2800—3300m,有机质可进入成熟早期和中期,砂岩则处于成熟Ⅰ阶段。这样,大量低成熟石油能够生成,并随着粘土释放出的层间水运移到砂岩的第一次生孔隙密集在中。高演化带位于3300—4000m左右,在该深度上,由于高成熟石油和凝析气在成熟晚期生成,并沿着泥岩的微裂隙运移到深部储集层的第二次生孔隙密集带中,这是一个油气开采的潜在层段。

The first member of Dainan Formation(E1d1)in Gaoyou Depression, Northern Jiangsu can be devided into high, middle and low evolutionary zones in which the depth for the middle evolutionary zone is of 2800m-3300m. Its organic matter has evoluted to early and middle maturation stages. So that a large amount of low-mature oil was generated and subsequently migrated into sandstone belt with first secondary porosity created by the formation water released from clays. The depth of the high evolutionary zone is about 3300m-4000m where highly mature oil and condensate gas were generated at the later stage of maturation. Thereafter, the oil/gas migrated to the belt with second secondary porosity along the microfractures in claystones,and such a zone would be a favourable interval with a significant oil/gas potential.

https://doi.org/10.11781/sysydz198803223