Wang Guicheng, Wang Xiaolin, Xie Licheng, Huang Ruili
Xi'an Shiyou University, Xi'an, China.
China University of Petroleum (Beijing), Beijing, China.
Sci Rep. 2024 May 8;14(1):10545. doi: 10.1038/s41598-024-60510-y.
The Fuxian-Yan10 layers are the main oil-producing reservoirs of Jurassic in Wuqi-Dingbian area of Ordos Basin. However, due to the lack of understanding of the pattern and distribution characteristics of oil reservoirs, the benefits of exploration and development are restricted. In order to provide theoretical guidance for the study of similar geological features, based on the analysis of paleogeomorphic features and evolution, the analysis focuses on the influence of palaeo-geomorphology on oil reservoir distribution, and summarizes the main types of reservoir models in the study area. The results show that there are four types of palaeo-geomorphic units in the Wuding area: palaeo-river, slope, highland and interriver hill. In the study area, the Jurassic paleogeomorphology controls the sedimentary development and distribution from Fuxian Formation to Yan 9 Formation. The compacted structure and lithologic barrier provide good trapping conditions for the paleogeomorphic oil. Moreover, the swampy coal measures and mudstone at the top of Yan 9 play a sealing role for oil accumulation, and the bottom water was obviously driven. In addition, the pre-Jurassic deep valley was the main channels for oil migration. On this basis, it is concluded that there are four reservoir-forming models in Wuding area: slope type, river hill type, ancient river type and highland type.
富县—延10油层组是鄂尔多斯盆地吴起—定边地区侏罗系的主要产油层。然而，由于对油藏的分布规律和特征认识不足，制约了勘探开发效益。为了给类似地质特征的研究提供理论指导，在分析古地貌特征及演化的基础上，重点分析古地貌对油藏分布的影响，并总结研究区油藏模式的主要类型。结果表明，吴定地区发育古河道、斜坡、高地、河间山4种古地貌单元。研究区侏罗纪古地貌控制了从富县组到延9组的沉积发育与分布。压实构造和岩性遮挡为古地貌油藏提供了良好的圈闭条件。此外，延9顶部的沼泽相煤系及泥岩对油藏起到封盖作用，底水驱动明显。另外，侏罗纪前的深谷是油运移的主要通道。在此基础上，总结出吴定地区存在斜坡型、河丘型、古河道型和高地型4种成藏模式。
