应力加载及卸载对致密油层孔隙度的影响

Effect of stress loading and unloading on tight oil reservoir porosity

致密砂岩油层孔隙度受地层有效应力的影响。本文通过实验研究了不同的应力加载/卸载速率以及黏土矿物含量对致密砂岩孔隙度的影响。结果表明,应力加载及卸载速率越大,岩心孔隙度保留率及恢复率越小;岩心黏土矿物含量越高,应力加载及卸载过程中岩心孔隙度保留率及恢复率越小。

Porosity of tight sandstone oil reservoirs is affected by formation effective pressure.In this article,effects of different stress loading/unloading rate and different clay mineral content on tight sandstone porosity were researched through tests.And results indicate that the stress loading/unloading rate greater,the retention ratio and recovery ratio of porosity are smaller;the clay mineral content higher,the retention ratio of porosity during stress loading and recovery ratio of porosity during stress unloading are smaller.