梁11断块沙河街组二段河口坝砂岩体夹层特征

Interlayer characteristics of estuary dam reservoir of the 2nd member of Shahejie formation in L11 fault block

综合岩心、测井资料及其综合解释成果,对梁11断块沙河街组二段夹层的结构层次、岩石类型、成因等进行系统研究和分类,并通过井间对比及夹层平面分布研究,分析河口坝环境中不同位置、不同类型夹层的分布规律。结果表明:夹层的岩石类型分为泥质、钙质及过渡性3类,依照稳定性及封隔性能可分为A,B,C3个级别,其中A级夹层具有较好的封隔及阻流作用;坝主体位置的夹层以钙质夹层、过渡性夹层为主,厚度较小且不甚稳定、封隔性较差;坝缘和坝侧翼的夹层以泥质夹层为主,厚度较大且相对较稳定,封隔性能较好;坝顶位置的夹层数量少且厚度变化不稳定。

Synthetically using the core,log curve and their processing results,the types of interlayers about hierarchy,lithology and cause of the 2nd member of Shahejie formation in L11 fault block were studied. The distribution characteristics of interlayers of different types of sandwich and in different position of estuary dam reservoir through contrasting developmental differences of interlayers among wells and plane distribution were analyzed. The results show that there are 3 categories of rock types such as clay interlayer,calcareous interbeds and transitional interlayers. Interlayers can be classified A,B,C three levels according to stability and containment performance. A level has a good isolation and blocking effect. There are calcareous interbeds and transitional interlayers in the subject positions of estuary dam,which has small thickness,less stability and poor barrier. There are clay interlayer in dam edge and flank,which has great thickness,relative stability and good barrier. The number of interlayers is few at the top of dam,and thickness change is unstable.