石油与天然气地质 ›› 2019, Vol. 40 ›› Issue (3): 512-523.doi: 10.11743/ogg20190307

• 油气地质 • 上一篇    下一篇

东营凹陷页岩油储集地质特征与有效性

刘惠民1, 张顺2, 包友书2, 方正伟2, 姚素平3, 王勇2   

  1. 1. 中国石化 胜利油田分公司 油气勘探管理中心, 山东 东营 257001;
    2. 中国石化 胜利油田分公司 勘探开发研究院, 山东 东营 257015;
    3. 南京大学 地球科学与工程学院, 江苏 南京 210023
  • 收稿日期:2018-12-28 修回日期:2019-03-28 出版日期:2019-06-28 发布日期:2019-04-26
  • 作者简介:刘惠民(1969-),男,教授级高级工程师,油气勘探研究与管理。E-mail:hmliu@vip.163.com。
  • 基金资助:
    国家科技重大专项(2017ZX05049-004-002)。

Geological characteristics and effectiveness of the shale oil reservoir in Dongying sag

Liu Huimin1, Zhang Shun2, Bao Youshu2, Fang Zhengwei2, Yao Suping3, Wang Yong2   

  1. 1. Manage Center of Oil & Gas Exploration of Shengli Oilfield Branch Company, SINOPEC, Dongying, Shandong 257001, China;
    2. Exploration and Development Research Institute, Shengli Oilfield Branch Company, SINOPEC, Dongying, Shandong 257015, China;
    3. School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023
  • Received:2018-12-28 Revised:2019-03-28 Online:2019-06-28 Published:2019-04-26

摘要: 以济阳坳陷东营凹陷古近系泥页岩为研究对象,通过岩心观察、偏光显微镜、氩离子抛光-扫描电镜分析以及高压压汞、小角X射线散射等实验,表征泥页岩不同尺度储集空间类型及组合连通方式,结合孔隙度、含油饱和度等数据,明确其储油的孔径及孔隙度下限。综合热演化程度(Ro)、岩相发育特征、地层压力特征和储集空间发育特征(孔隙度和孔径)等因素,建立东营凹陷泥页岩储集空间发育分布模式,预测页岩有利储集相带。结果表明:①研究区泥页岩储层孔隙类型主要为粒间孔、有机质和粘土矿物收缩孔及碳酸盐晶间孔,且具有三级孔缝网络的连通形式;②粘土片间孔和碳酸盐晶间孔对总孔隙度的贡献率最高,平均可达50%~70%,其次为粘土收缩缝和构造张裂缝;③页岩油赋存的孔径下限、游离油赋存孔径下限以及游离油大量富集的孔径门槛值,分别为5、10和30 nm;④富有机质和富碳酸盐矿物的纹层状页岩在总孔隙度、孔隙连通率和有利于游离油赋存的孔隙所贡献的孔隙度等方面最好,可作为优势岩相类型;⑤泥页岩岩相类型、成岩阶段、地层压力与裂缝发育程度控制了储集空间的发育分布特征,也是页岩油甜点评价的重要因素;有利储集相带预测就是在储集分级评价方案的指导下,寻找富有机质纹层状页岩分布区、相对较高的热演化程度页岩发育区、裂缝发育区、高地层压力发育区等叠合区。

关键词: 页岩油, 储集空间, 孔径, 岩相, 有利储集相带, 沙河街组, 东营凹陷, 济阳坳陷

Abstract: The reservoir space types of various sizes and their connection patterns of the Paleogene shale in Jiyang Depression were characterized through core observation,polarizing microscope and argon ion milling-scanning electron microscopy (SEM) analyses,and high pressure mercury injection,as well as small angle X ray scattering experiment; in addition,the lower limits of effective pore diameter and porosity were clarified according to data such as porosity and oil saturation.A spatial development and distribution model of shale reservoir in Dongying sag was established to predict the favorable reservoir facies belt through integrating thermal maturity (Ro) with the characteristics of lithofacies,formation pressure,and reservoir space (porosity and pore diameter).The results show that:(1) the pores of the shale reservoir in the study area are mainly intergranular pores,shrinkage pores in organic matter and clay minerals,and intercrystalline pores in carbonate,all of which are connected through a three-level pore-fracture network; (2) the intraparticle pores in clay minerals and intercrystalline pores in carbonate are the most effective pores with the highest contribution to the total porosity,averaging at 50% to 70%,followed by clay shrinkage cracks and tension fissure; (3) the lower limit of pore diameter for shale oil occurrence,the minimum pore diameter for free oil occurrence,and the threshold pore diameter of free oil enrichment are 5nm,10nm and 30mm,respectively; (4) the laminated shale rich in organic matter and carbonate minerals is the highest in total porosity,pore connectivity,and contribution of pores favorable for free oil storage to porosity,so it is a preferential lithofacies; (5) the development and distribution characteristics of shale reservoir space are controlled by the lithofacies type,diagenetic stage,formation pressure and fracture development degree,all of which also serve as important factors for the evaluation of shale oil sweet spots; the prediction of favorable reservoir facies belt is to identify laminated organic-rich shale with relatively higher thermal maturity,highly-developed fracture and high formation pressure under the guidance of graded evaluation scheme.

Key words: shale oil, reservoir space, pore diameter, lithofacies, favorable reservoir facies belt, Shahejie Formation, Dongying sag, Jiyang Depression

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