塑性组分对压实作用和储层物性的控制作用——以白音查干凹陷缓坡带下白垩统腾格尔组碎屑岩储层为例

The controlling effect of plastic component on compaction and reservoir physical properties:a case study of Lower Cretaceous Tengger Formation clastic reservoir in the gentle slope zone of Baiyinchagan Sag

塑性组分与压实作用和储层物性之间的定量关系目前尚不清楚。文中选取白音查干凹陷缓坡带开展塑性组分含量和压实量、储层孔隙度定量关系研究,探讨塑性组分对压实作用和储层物性的控制作用。白音查干凹陷缓坡带发育锡林好来、达尔其和翁特三大物源区,母岩形成的片岩岩屑和云母碎屑组成塑性组分。锡林好来和翁特地区塑性组分含量较低,与压实量不存在明显相关关系,储层孔渗随深度增大,减小较慢;达尔其地区塑性组分含量较高,且与压实量存在明显正相关关系,储层孔渗随深度增大,减小较快。研究显示:塑性组分含量较低(体积分数低于10%)时,对压实量和储层物性影响较小;塑性组分含量较高(体积分数高于10%)时,对压实量和储层物性具有明显的控制作用。

The quantitative relationships between plastic component and the compaction and reservoir physical properties are unclear at present.In this paper,a quantitative study of plastic component content,compaction volume and reservoir porosity was conducted in the gentle slope zone of Baiyinchagan Sag to investigate the controlling effect of plastic component on compaction and reservoir physical properties.It developes three major provenances of Xilinhaolai,Daerqi and Wengte in the gentle slope zone of Baiyinchagan Sag.The schist rock fragments and mica fragments formed by parent rocks comprise the plastic component.The contents of the plastic component are low in Xilinhaolai and Wengte area,which has no significant correlation with the compaction volume,and reservoir porosity and permeability decrease slowly with increasing depth.The contents of the plastic component are high in Daerqi area,which has a significant positive correlation with the compaction volume,and reservoir porosity and permeability decrease quickly with increasing depth.The study shows that when the volume fraction of plastic component is low(below 10%),it has less influence on the compaction volume and reservoir physical properties,and when the volume fraction of plastic component is high(above 10%),it has obvious controlling effect on the compaction volume and reservoir physical properties.