长期注水开发砂岩油田储层渗透率变化规律及微观机理

大庆喇萨杏油田为典型的陆相非均质砂岩油田，其储层非均质性强，由于不同渗透率储层孔喉结构特征、黏土矿物构成等存在差异，水驱前后表现出各不相同的变化特征，进入特高含水开发阶段后，“三大矛盾”更加凸显。综合利用扫描电镜、铸体薄片、核磁共振、检查井分析、驱油实验和生产动态等资料，系统研究了不同渗透率储层水驱前后渗透率的变化规律，量化了不同渗透率储层水驱前后渗透率变化幅度，从储层黏土矿物、粒度中值、孔隙分布和孔喉特征等方面分析了导致渗透率变化差异的机理，阐述了不同渗透率储层参数变化对注水开发的影响，从而对特高含水期不同类型储层控水挖潜有一定的指导作用。

Variation law and microscopic mechanism of permeability in sandstone reservoir during long-term water flooding development

Daqing La-Sa-Xing oilfield is a typical continental heterogeneous sandstone oilfield with strong reservoir heterogeneity. Due to the differences in pore throat structure characteristics and clay minerals composition of the reservoirs with diversified permeability, different variation characteristics are shown before and after water looding. After entering the ultra-high water-cut development stage, three major contradictions are more prominent. Scanning electron microscopy, cast sheet, nuclear magnetic resonance, inspection well analysis, flooding experiment, production performance and other data were comprehensively adopted to study the permeability variation laws and quantize the permeability change amplitude of the reservoirs with diversified permeability before and after water flooding. The mechanism for permeability variation difference was analyzed in terms of the clay minerals composition, median grain diameter, pore distribution and pore-throat characteristics of reservoirs. Meanwhile, this paper also narrates the influence of parameter changes in the reservoirs with diversified permeability on water flooding, which has a guiding role in tapping oil potential through water control in different types of reservoirs during the ultra-high water-cut stage.