低渗岩芯应力敏感性升降法实验研究

Lifting-Method Experimental Study on Stress Sensitivity of Low-Permeability Core

研究了低渗岩芯的应力敏感性,即油气层的渗透率随有效应力的变化而发生改变的现象。在岩芯常规孔隙度、渗透率测试的基础上,对CQ油田某区块柱塞岩芯分别进行变内压恒外压和变外压恒内压测试。实验结果表明,变内压恒外压更符合油田开发的实际,随多次应力敏感次数的增加,应力敏感性变弱,甚至趋于一个极限。

Stress sensitivity refers to the reservoir permeability change with the effective stress.Based on the conventional core porosity and permeability tests,we developed Change Inside Pressure Keep Outside Pressure Test method on five piston cores from CQ Oilfield.Experimental results show that Change Inside Pressure Test is more in accordance with actual oilfield development.With the increase of stress-sensitive number,variable stress sensitivity becomes weaker,and even tends to a limit.