中国石油勘探 ›› 2024, Vol. 29 ›› Issue (5): 91-105.DOI: 10.3969/j.issn.1672-7703.2024.05.008

• 石油地质 • 上一篇    下一篇

鄂尔多斯盆地南缘宁县—正宁地区延长组地层结构重建及页岩油富集模式探讨

胡英杰,李晓光,单俊峰,刘兴周,谷团,鞠俊成,牟春,王宇斯   

  1. 中国石油辽河油田公司
  • 出版日期:2024-09-14 发布日期:2024-09-14
  • 作者简介:胡英杰(1973-),男,吉林通化人,博士,2001年毕业于中国石油勘探开发研究院矿产普查与勘探专业,教授级高级工程师,现主要从事石油地质综合研究工作。地址:辽宁省盘锦市兴隆台区辽河油田公司,邮政编码:124010。

New cognition on stratigraphic structure of Yanchang Formation and discussion on enrichment model of shale oil in Ningxian—Zhengning area, southern Ordos Basin

Hu Yingjie,Li Xiaoguang,Shan Junfeng,Liu Xingzhou,Gu Tuan,Ju Juncheng,Mou Chun,Wang Yusi   

  1. PetroChina Liaohe Oilfield Company
  • Online:2024-09-14 Published:2024-09-14

摘要: 鄂尔多斯盆地延长组页岩油资源丰富,但不同地区勘探研究程度差异大,延长组地层结构及页岩油形成及富集控制因素认识有待深化。利用伊陕斜坡南部宁县—正宁地区新采集的三维地震资料,以及区内的钻井、录井、测井、各类分析测试成果,对延长组地层分布结构和长7段页岩油形成及富集控制因素进行了探讨。综合研究认为,研究区延长组长7段—长2段地层具有逐层向湖盆中心进积的楔状地层结构特征;延长组物源主要来自秦岭造山带,各期楔形地层内顺物源方向以河流—三角洲—半深湖—深湖重力流序列充填,具有“同期异相”特征;长7 段发育砂质碎屑流及浊流沉积,储层横向变化快,非均质性强,总体属于低孔—特低孔、超低渗致密储层;延长组围绕长7段主力烃源岩,具有上生下储、自生自储、下生上储三种成藏组合类型,长7段主要发育自生自储(夹层)型页岩油,具有优质烃源岩—优势相带—断裂—构造共同控藏特征,其中烃源岩控制页岩油有利发育区,优势相带和断裂控制页岩油富集部位。

关键词: 鄂尔多斯盆地, 宁县—正宁地区, 延长组, 地层结构, 长7 段, 页岩油, 控制因素, 富集模式

Abstract: Ordos Basin is rich in shale oil resource with different level of exploration and cognition basin-wide, and stratigraphic structure of Yanchang formation, forming and controlling factors on enrichment for shale oil need to be deepened.The stratigraphic structure of Yanchang Formation is re-established, and the controlling factors on formation and enrichment are discussed for shale oil of Member Chang7 through the full application of newly acquired high-density and wide-azimuth 3D seismic data, combining drilling logging and analytical data in Ningxian-Zhengning area, southern Yishan Slope belt. The latest comprehensive study show that Member Chang 7 to Chang2 of Yanchang formation has the stratigraphic structure of wedge-shaped development and progradation layer by layer towards the lacustrine center, the provenance of Yanchang formation is mainly from the Qinling Orogenic Belt for Ningxian-Zhengning area, and sedimentary sequence of single-stage wedgeshaped formation is filled with fluvial-delta, semi-deep lake, deep-lake gravity-flow deposits along the sediment-supply direction, which has the characteristics of “same period with different sedimentary facies”. Deposits of sandy debris flow and turbidity flow are developed in Member Chang7 mainly, which belong to low-porosity and ultra-low porosity ultra-low permeability tight reservoir generally with characteristics of rapid lateral change and strong reservoir heterogeneity. The low-permeability, tight oil and shale oil reservoirs are continuously developed encompassing the main source rock of chang 7, resulting in three reservoir combination types including reservoir below source rock, reservoir and source rock co-existing in same layer, reservoir above source rock in Yanchang Formation. intercalated shale oil mainly exists in Chang7, controlled by combination of high-quality source rock, advantageous microfacies, fractures and structure. High-quality source rock controls beneficial distribution range of shale oil,sedimentary facies and fractures control enrichment area.

Key words: Ordos Basin, Ningxian-Zhengning area, Yanchang Formation, stratigraphic structure, Member Chang 7, shale oil, controlling factor, enrichment model

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