东营凹陷沙三段下亚段细粒沉积岩岩相特征及其分布模式

发布时间：2018-06-23 11:25

本文选题：细粒沉积岩 + 岩相　；参考：《油气地质与采收率》2017年01期

【摘要】：综合运用岩心观察、薄片鉴定、X衍射和扫描电镜等分析方法,对东营凹陷沙三段下亚段细粒沉积岩矿物组成、沉积构造和纹层类型及成因进行精细刻画,在此基础上建立细粒沉积岩岩相划分方案,并以樊页1井沙三段下亚段为例分析其岩相垂向演化特征。东营凹陷沙三段下亚段细粒沉积岩具有矿物组成复杂多变、受底流微弱改造作用频繁及纹层类型丰富的特点。参考矿物组成和沉积构造,研究区发育11种岩相类型,其中平直纹层粘土岩相、夹层灰岩相、平直纹层灰岩相、不平直纹层灰岩相、平直纹层混合岩相、不平直纹层混合岩相和块状混合岩相是最为发育的7种岩相类型,不同岩相发育环境差异性明显。细粒沉积岩岩相分布模式受古水深和古气候综合控制,在气候干冷、深水还原环境下主要发育平直纹层粘土岩相;气候由干冷向暖湿转变时形成夹层灰岩相;在气候半暖湿的广阔深湖环境下发育平直纹层灰岩相;在气候最为暖湿时期,底流发育,形成不平直纹层灰岩相;随着水深减小,水体分层不稳定,加之气候逐渐干冷,形成平直纹层混合岩相,若底流发育,则形成不平直纹层混合岩相;在半氧化—半还原的浅湖环境下发育块状混合岩相。
[Abstract]:By means of core observation, thin slice identification, X-ray diffraction and scanning electron microscopy, the mineral composition, sedimentary structure, type and origin of fine sedimentary rocks in the lower submember of the third member of Sha in Dongying Sag are described in detail. On the basis of this, the facies division scheme of fine-grained sedimentary rocks is established, and the vertical evolution characteristics of its lithofacies are analyzed by taking the lower sub-member of Sha-3 member of well Fan Pian 1 as an example. The fine-grained sedimentary rocks of the lower member of the third member of the Shahejie formation in Dongying depression are characterized by complex mineral composition frequent weak transformation of the bottom flow and rich types of laminae. With reference to mineral composition and sedimentary structure, there are 11 types of lithofacies developed in the study area, including plain grain clay facies, intercalated limestone facies, flat grain limestone facies, irregular grain limestone facies, flat grain mixed lithofacies, and so on. The migmatite facies and block migmatite facies are the most developed seven lithofacies types, and the development environment of different lithofacies is obviously different. The lithofacies distribution model of fine-grained sedimentary rocks is controlled by paleo water depth and paleoclimate. In dry and cold climate and deep water reduction environment, clay facies of flat grain are mainly developed, and intercalated limestone facies are formed when climate changes from dry cold to warm and wet. In the wide deep lake environment with semi-warm and humid climate, the plagitic limestone facies is developed; in the most warm and humid climate, the bottom flow develops, forming the irregular striated limestone facies; with the decrease of the water depth, the water layers are unstable and the climate is gradually dry and cold. The mixed lithofacies of the flat grain layer is formed, if the bottom current is developed, the mixed lithofacies of the irregular grain layer is formed, and the massive mixed rock facies is developed in the semi-oxidation-half-reduction shallow lake environment.
【作者单位】：中国石化胜利油田分公司勘探开发研究院;中国石油大学(华东)地球科学与技术学院;山东省地质调查院;
【基金】：国家“973”计划“陆相页岩油储集空间与发育模式”(2014CB239102) 国家科技重大专项“济阳坳陷页岩油勘探开发目标评价”(2017ZX05049-004) 山东省地质勘查项目“山东省页岩气成矿条件研究和资源潜力预测”(鲁勘字(2013)1号)
【分类号】：P618.13;P512.2

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