A地区延长组B层页岩油储层渗流特征研究

Research on the seepage characteristics of B segment shale oil reservoir of Yanchang formation in the A region

A地区延长组B层页岩油资源前景十分广阔,但有效的压力驱替系统难建立,地层能量补充困难。为进一步提升勘探开发效果,在前人研究的基础上,利用室内实验数据,从相渗曲线、油水分布等方面,分析和明确了页岩油储层的典型渗流特征。结果表明:研究区B层页岩油储层呈现出高束缚水饱和度和高残余油饱和度的“双高”特征;页岩油岩心束缚水的T2谱分布区间以1~10 ms的孔隙为主,残余油的T2谱分布区间以10~100 ms的孔隙为主;页岩油储层可动流体主要赋存在0.10~1.00μm的孔喉中,与渗透率具有正相关性;B层页岩油储层启动压力梯度大,难以建立有效的驱替系统,注水驱油效率低。

The shale oil of Yanchang formation of B segment resources in the A region have a very broad prospect,but it is difficult to establish an effective pressure displacement system,and it is difficult to replenish the formation energy.In order to further improve the exploration and development effect,based on previous research,this study utilizes indoor experimental data to analyze and clarify the typical seepage characteristics of shale oil reservoirs from aspects such as phase relative permeability curves and oil-water distribution.The results show that the shale oil reservoir of B segment in the study area exhibits the"double high"characteristics of high bound water saturation and high residual oil saturation.The T2 spectrum distribution range of bound water in shale oil core is mainly in pores of 1~10 ms,while the T2 spectrum distribution range of residual oil is mainly in pores of 10~100 ms.The movable fluid in shale oil reservoirs is mainly distributed in throat pores of 0.10~1.00μm,which is positively correlated with permeability.The starting pressure gradient of shale oil reservoir of B segment is large,making it difficult to establish an effective displacement system,and the waterflooding oil recovery efficiency is low.