塔河油田9区下油组块状叠置厚油层渗流屏障研究

Research on Seepage Barriers of Massive and Superimposed Thick Oil Layers in the Low Oil Formation of No.9 Block in Tahe Oilfield

塔河油田9区三叠系阿克库勒组下油组储层为典型的块状叠置辫状河三角洲储层,夹层分布及连通性极其复杂,封闭断层和泥质屏障、钙质胶结帯等不同级次渗流屏障控制着油藏内部油水运动。为深化储层空间非均质表征,在储层构型分析基础上,笔者采用层次分析方法,动静态相结合,对渗流屏障类型及其级次进行划分,分析泥质屏障、钙质胶结帯形成机理及其受控因素,建立块状厚油层渗流屏障分布地质模型。研究表明:塔河油田9区下油组主要渗流屏障为封闭断层屏障和层间、层内发育的泥质及钙质隔夹层;依据渗流阻挡作用分为4个级次,东北向封闭性断层及复合河道顶部6级界面是1级渗流屏障,3~5级构型界面控制了2~4级泥质、钙质渗流屏障的发育,建立完全不遮挡型、部分遮挡型及完全遮挡型等3种渗流屏障模式。通过分级次定量表征渗流屏障的空间分布,深化储层空间非均质性研究,为基于流动单元的精细地质建模奠定基础。

The low oil formation reservoir of No.9 block in the Tahe Oilfield is a superimposedmassive braided river delta reservoir,moreover,distribution and connectivity of the interlayers as well as complexity produced the sealing faults,argillaceous barriers,calcareous cemented zones and other different–level seepage barriers to control the movement of oil and water within the reservoir is to deepen the heterogeneity of the reservoir space;and the analytic hierarchy process is adopted based on the analysis of the reservoir configuration,and combined with dynamic and static,to clarify the seepage barrier types and levels;the formation mechanism of calcareous cement zone and its controlling factors is analyzed by researcher,so that establishes a geological model for the distribution of seepage barriers in massive thick oil layers;Researches show that the main seepage barriers of the low oil formation in No.9 Block of Tahe Oilfield are sealing faults barriers,mud barriers,and cal-cium cemented zones,what is more,it can be divided into four levels according to the seepage blocking effect,and northeast sealing faults and the 6-level interface at the top of the composite channel are the first-level seep-age barrier,the 3~5 level configuration interface controls the 2~4 level mud and calcareous seepage barriers;to establish three types of seepage barrier modes composed by completely uncover,partial cover,and complete-ly cover.The spatial distribution of seepage barriers is characterized by hierarchical and sub-quantitative meth-ods,which deepening the study of reservoir spatial heterogeneity,and laying the foundation for fine geological modeling based on flow units.