地震沉积学在复杂岩性地区的应用——以歧北凹陷沙二段为例

以地震沉积学理论为指导,立足于地震岩性学和地震地貌学,在歧北凹陷沙二段滨4油组开展地震沉积学研究。针对研究区复杂岩性波阻抗值差异小以及自然伽马值差异明显的特点,开展相对波阻抗约束下的测井参数反演工作来获取岩性数据体。同时,结合测井和钻井资料,对地层切片进行地震沉积学解释。研究结果表明:测井参数反演方法可以有效区分研究区的复杂岩性,基于等时地层格架生成的一系列地层切片识别出了滨4油组三角洲—湖泊沉积体系中不同的沉积单元,准确反映了其物源方向、储层平面展布特征及空间演化史。

Application of seismic sedimentology in the area with complex lithologies:A case from the second member of Shahejie Formation in Qibei Sag

With the guidance of seismic sedimentology theory,the seismic sedimentology study was carried out in the Bin-4 oil group of the second member of Shahejie Formation in Qibei Sag based on the research of seismic lithology and geomorphology.According to the geophysical response features of complex lithologies,the log parameter inversion constrained by relative acoustic impedance was conducted to obtain lithologic data.With the help of logging and well drilling data,the stratal slices were interpreted.The result shows that log parameter inversion can be used to distinguish the complex lithologies.The source direction,evolutional history and reservoir distribution characteristics of the sandstone of delta-lacustrine depositional system in Bin-4 oil group were clearly delineated by a series of stratal slices produced under the isochronous stratigraphic framework.