Abstract: In the development of loose sandstone reservoirs，the problem of particle migration blockage is very common. When the particle migration is blocked，the fluid produced is greatly reduced，which constrains the development of this type of reservoir. To understand the mechanism and main controlling factors of particle blockage，the microscopic pore throat characteristics were observed from PX oil field cast thin sections，and a microscopic pore structure model was prepared using laser etching to simulate the migration and blockage mechanism of particles with different particle sizes，viscosity，flow rate，and concentration. The effects of particle size to throat ratio，fluid viscosity，solid phase particle concentration，and flow rate on particle migration/blockage were systematically evaluated. It was found that the particle concentration，particle size，pore throat size，fluid viscosity and displacement velocity were the main controlling factors affecting particle migration. When the ratio of particle size to throat diameter is greater than 2/3，large-scale blockages are easily formed. The factors influencing particle migration at different water content stages in the oilfield vary，and the fluid viscosity，fluctuation in fluid production，rising water cut，and adjustments to the production system can all cause particle migration blockage.

Key words:

">  , loose sandstone, particle migration, laser etching, reservoir blockage, plogging of pore throat, velocity sensitivity

摘要：

疏松砂岩油藏开发中微粒运移堵塞造成的油井产液能力大幅下降问题是制约该类油藏开发效果的关键节点。为了搞清微粒堵塞的机理及主控因素，根据PX油田铸体薄片观察微观孔喉特征，利用激光刻蚀制备了微观孔隙结构模型，模拟了不同粒径、黏度、流量、浓度下的微粒运移堵塞机理。系统评价了微粒粒径与喉道比值、流体黏度、固相颗粒浓度、流量等对微粒运移/堵塞的影响。认识到微粒浓度、微粒粒径和孔喉大小、流体黏度、驱替速度是影响微粒运移的主控因素。微粒粒径与喉道直径之比大于2/3时容易形成大规模堵塞。矿场中不同含水阶段微粒运移的影响因素不同，流体黏度、产液波动、含水上升、生产制度调整等都会造成微粒运移堵塞。

关键词:

"> 疏松砂岩, 微粒运移, 激光刻蚀, 储层堵塞, 孔喉堵塞, 速敏