拟启动压力对低渗透单相流体及油水两相渗流的影响--以沙埝油田沙7断块为例

Effects of starting pressure on single phase fluid and oil/water two-phase fluid flow in low permeability reservoir-case study in Sha 7 fault block in Shanian Oilfield

应用压差—流量法测定岩心启动压力,根据实验结果和数学方法分析启动压力对油水渗流的影响,并对达西公式和JBN计算方法进行改进,推导出适合低渗透储层规律的公式。研究结果表明,由于启动压力的存在,低渗透油藏油水渗流非达西现象突出,借用达西公式所获得的视渗透率随压力梯度发生变化,当压力梯度达到最大启动压力梯度时,渗流进入拟线性流阶段。

The core pressure gradient was measured applying the pressure difference-flux method,the effects of starting pressure on oil-water flow were analyzed based on the experiment result and mathematics method,and the JBN method and Darcy formulation were modified and the formulation appropriate to low permeability reservoir was deduced in this paper.According to the test result,the phenomenon of non-Darcy flow was extraordinarily distinct when oil and water flow inside the low permeability reservoir because of the starting pressure.The apparent permeability calculated in Darcy formulation would change with the pressure gradient,and the fuid flow would be linear when the pressure gradient reached the maximum starting pressure gradient.