注入流体中的悬浮固体微粒随流体进入储层后会对储层造成伤害,导致储层渗透率降低,明确不同因素对储层伤害的影响规律对现场储层伤害的预防和治理有十分重要的意义。因此应用网络模拟方法对不同条件下储层伤害变化规律及孔喉变化规律进行了研究。模拟结果表明:随驱替的不断进行,孔喉半径总体逐渐减小,且距离注入端面越近,孔喉半径减小幅度越大;注入流量越小、注入流体内微粒浓度越大、流体黏度越小、微粒粒径越大,越有利于微粒的沉积,造成的储层伤害越严重。
Particles suspended in injection water could damage the formation and decrease the permeability. And it’s of great importance to study the impact of various factors on the formation impairment for its prevention and treatment. In our study here,pore scale network modeling method is applied to the study of the formation damage patterns and the change of the pore-throat radius under various conditions. In network models,different microcosmic particle variation mechanisms are taken into consideration. The results indicate that the pore-throat radius will decrease with the process of waterflooding and pore-throats that are closer to the inlet face will have a much higher decrease of their radius. Besides,the lower the flow rate is,the higher the particle concentration in injection water is,the lower the fluid viscosity and bigger particle size,it will be beneficial for the formation damage.