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以渤海湾盆地南部东营凹陷沙河街组三段-四段和沧东凹陷孔店组二段细粒沉积岩为研究对象,通过厘米级岩心观察描述、岩石薄片鉴定、X射线衍射分析、扫描电镜观察、地球化学测试、岩石力学及压裂模拟实验等方法明确了细粒沉积岩的基本特征、划分了岩相类型、对储层基本特征进行分析,认为断陷湖盆细粒沉积岩发育多种岩相类型,不同凹陷岩相类型存在差异,储层孔隙和裂缝类型多样,可压裂性较好.结果表明:黏土矿物质量分数普遍小于30%,碳酸盐质量分数大于30%.纹层状(粉砂质、云灰质)细粒混合沉积岩最为发育,东营凹陷典型岩相类型为纹层状灰岩相、页状黏土岩相,沧东凹陷典型岩相类型为纹层状白云岩相、块状白云岩相.层间缝、构造缝、粒间孔、粒内溶孔、晶间孔是最主要的储集空间类型.岩石力学特征方面表现出较高杨氏模量(平均为20GPa)、较低泊松比(平均为0.242)、较低断裂韧性(平均为0.26 MPa·m(1/2))、脆性指数整体较高(集中在40~60)等特征.
Fine grained sedimentary rocks in the second member of Kongdian Formation in the fourth member of Shahejie Formation and the Cangdong Depression in the Dongying Sag, southern Bohai Bay Basin, are studied. Centroid observation, centrometal identification, X-ray diffraction analysis and scanning electron microscopy , Geochemical tests, rock mechanics and fracturing simulation experiments and other methods to clear the basic characteristics of fine sedimentary rocks, divided the lithofacies type, the basic characteristics of the reservoir analysis that the fine-grained sedimentary faulted lake developed a variety of lithofacies Types and different diagenesis facies types, and the types of reservoirs and fractures are diverse and the fracability is good.The results show that the mass fraction of clay minerals is generally less than 30% and the carbonate mass fraction is more than 30% Silty, and calcareous) fine-grained mixed sedimentary rocks. The typical lithofacies in Dongying depression are laminar limestone facies, page-like clay facies and Cangdong Sag typical lithofacies dolomite facies, Shaped dolomite facies, interlamellar seams, structural seams, intergranular pores, intragranular dissolution pores and intergranular pores are the most important types of reservoir space.The rock mechanics characteristics show high Young’s modulus (average 20 GPa) , More Poisson’s ratio (average 0.242), fracture toughness is low (average of 0.26 MPa · m (1/2)), the higher the overall brittleness index (concentration 40 to 60) and other features.