内蒙古银额盆地居延海坳陷X井地层划分修正及其油气地质意义

The revision of stratigraphic division of X well in Juyanhai depression,YingenEjin Banner basin,Inner Mongolia,and its geological significance

对银额盆地居延海坳陷X井主要烃源岩发育层段和油气显示层段巴音戈壁组的生物组合、岩石学特征、碎屑岩颜色,以及镜煤反射率随深度变化等进行综合分析,提出了原地层划分存在的问题。通过与路井凹陷和路北凸起带的地层对比,以及过X井的地震反射特征分析,对主要岩石地层单元划分进行了修正。修正后的X井钻遇的主要烃源岩层段和含油显示层为二叠系,与路井凹陷及路北凸起的钻井资料一致,因此应将二叠系作为居延海坳陷油气勘探的主要目的层。

Based on a comprehensive analysis of characteristics of biological assemblies,petrologic features,clastic rock colors,the relationship between the vitrinite reflectance and the depth of Bayingebi Formation,and the main layer for development of source rocks of hydrocarbon shows,this paper puts forward the existent problems concerning the previous stratigraphic division.Therefore,in combination with stratigraphic correlation between Lujing depression and Lubeing convex belt as well as analysis of seismic reflection characteristics through X well,the authors significantly revised the division of some primary lithostratigraphic units.As a result,Permian strata are regarded as the major horizon of source rocks,as evidenced by the hydrocarbon shows in Permian intersected by revised X well,which is consistent with the drilling data of Lujing depression and Lubeing convex belt.The Permian strata are hence considered to be the major target strata for oil exploration in Juyanhai depression.