一种感温聚合物复合凝胶暂堵剂的制备及性能研究

Preparation and Performance of a Temperature-sensitive Polymer Composite Gel Temporary Plugging Agent

以丙烯酰胺(AM)和丙烯酸(AA)为共聚单体,运用传统的溶液聚合和纳米复合技术制备出具有特殊堵水性能的P(AA-AM)/MMT聚合物复合凝胶暂堵剂,将其作为基体堵水材料。利用聚多巴胺(PDA)的二级反应修饰平台,采用自组装技术将具有疏水特性的石蜡(C_(25)H_(52))组装在聚丙烯酰胺基复合凝胶暂堵剂表面,成功制备出了具有低温疏水、高温消溶表面的多级结构P(AA-AM)/MMT@C_(25)H_(52)聚合物功能复合凝胶暂堵剂。在实验室模拟油藏地层的环境下,分析了聚合物复合凝胶暂堵剂吸水倍率与不同影响因素(时间、温度及矿化度)之间的关系;考察了聚合物复合凝胶暂堵剂黏度和老化时间随包覆层功能材料含量的变化。结果表明:丙烯酸的中和度为80%时,聚合物凝胶吸水性能最佳。当石蜡的含量为4%(质量分数)时,在温度较低时,凝胶的溶胀性能相对较弱,聚合物复合凝胶暂堵剂的吸水倍率在60℃达到最优值。表面包覆的乳化石蜡层起到了延迟吸胀的作用,可提高暂堵剂的输送运移能力。

Temporary plugging agent with special water shutoff properties,based on P(AA-AM)/MMT polymer composite gel,was prepared via the traditional solution polymerization by using acrylamide and acrylic acid as comonomer,which can be used as the matrix material for water plugging agent.Using the second reaction modification platform of polydopamine(PDA),the hydrophobic paraffin wax(C_(25)H_(52))was assembled on the surface of polyacrylamide based composite gel temporary plugging agent by self-assembly technology.A multi-stage structure P(AA-AM)/MMT@C_(25)H_(52)with low temperature hydrophobicity and high temperature dissolution surface was successfully prepared.Under the laboratory environment of reservoir formation simulation,the relationship between water absorption rate of polymer composite gel temporary plugging agent and different influencing factors(time,temperature and salinity)was analyzed.The change of viscosity and aging time of polymer composite gel temporary plugging agent with the content of functional material of coating was investigated.The results show that the neutralization degree of acrylic acid is 80%,the water absorption performance of polymer gel is the best.With the content of paraffin wax 4wt%,the swelling property of the gel is relatively weak at low temperature,and the water absorption rate of the polymer composite gel temporary plugging agent reaches the optimal value at 60℃.The emulsified paraffin layer on the surface can delay imbibition and improve the transport capacity of temporary plugging agent.