聚丙烯酰胺类堵剂的堵水机理实验

真实砂岩孔隙模型驱替实验结果表明,聚丙烯酰胺类化学堵剂在储层孔隙中以优先选择封堵大孔道为主,堵剂进入孔道后的粘度变化为:大段塞低粘度、大段塞高粘度和小段塞高粘度。封堵机理及堵效产生过程表现为:孔道表面的吸附水膜机理凝胶网状絮凝体动力捕集机理物理堵塞粘弹封堵效应。另外,在相同堵水条件下,甲叉基聚丙烯酰胺(PHMP)与粘土复合堵剂更适合于大孔道和裂缝性储集层的化学调剖堵水,而PHMP与TP-920膨胀颗粒复合堵剂适宜于对大孔道大裂缝的封堵。

EXPERIMENT ON PLUGGING MECHANISM OF POLYACRYLAMIDE WATER PLUGGING AGENT

The result of visual displacement experiment of the sandstone pore micro model indicates that polyacrylamide chemical plugging agent should have priority to be selected as a chief agent for plugging wide channels in reservoirs. The viscosity variations of the plugging agent after entering the channel can be classified as follows: big slug with low viscosity; big slug with high viscosity and small slug with high viscosity. The process that formed plugging mechanism and plugging result can be described as: absorbed water film produced by pore channel surface-dynastic entrapment of gel network floc-unit-physical plugging- viscoelastic plugging effect. In addition, under the same water plugging condition, PHMP and clay composite plugging agents are more suitable for plugging wide channel and fractured reservoirs, whereas PHMP and TP-920 swelled-grain composite plugging agents are fit for plugging wide channels and fractures, the chemical plugging agent above shows that plugging result in double pore medium has more significance than that in single pore medium.