基于架状结构内核的热采井内刚外柔颗粒堵剂研究及应用

Research and Application of Particulated Plugging Agent with Hard Framework Core and Soft External Structure for Thermal Production Wells

采用具有架装结构能够吸附并储存交联剂的硅铝酸盐矿物作为刚性内核,以丙烯酰胺和丙烯酸为主要聚合单体,以N,N-亚甲基双丙烯酰胺为交联剂,以过硫酸铵-亚硫酸氢钠氧化还原体系为引发剂,通过甲基丙烯酸十二烷酯引入疏水基团,采用水溶液聚合法制备了一种内刚外柔堵剂。通过静态性能评价实验对内刚外柔堵剂的吸水膨胀性能、耐温抗盐性能、封堵性能进行考察,结果表明:内刚外柔堵剂可吸水体积膨胀6.0倍,质量膨胀12.0倍,吸水饱和时间大约10 h;在高盐条件下(50 g/L氯化钠溶液、10 g/L氯化钙溶液),吸水膨胀倍数变化不大,具有良好的耐盐性能;具有良好的耐温性能,耐温可达200℃;具有弹性变形推进和可进行二次封堵的优点,其封堵率可达99.5%,经过10 PV的冲刷后,封堵率仍可达到96.7%,封堵效果良好。现场试验3口蒸汽吞吐井,1口蒸汽驱井,均取得了良好的调堵增油效果。

A new plugging agent with hard framework core and soft external structure was prepared by aqueous solution polymerization,using the aluminosilicate with framework structure and absorbing and storing cross-linking agent capacity as rigid core,acrylamide and acrylic acid as main monomers,N,N-methylene bisacrylamide as cross-linking agent,ammonium sulfate-sodium bisulfite oxidation-reduction system as initiator,and introducing hydrophobic group through methacrylic acid dodecane fat. The water swelling performance,the temperature and salt resistance and the plugging performance of the new plugging agent were evaluated through the static experiments. The results show that after absorbing water,the volume of the plugging agent can expand 6. 0 times,its mass can increase 12. 0times,its water saturation time is about 10 h; in 50 g/L sodium chloride solution or 10g/L calcium chloride solution,its water swelling performance changes little,which shows that the plugging agent has good anti-salt performance; its temperature resistance can reach to 200 ℃; it has advantages of flexible deformation propulsion and secondary plugging,its plugging ratio can reach to 99. 5%,and the plugging ratio still reaches to 96. 7% after the scour of 10 PV. The plugging agent was applied to 3 steam huff-puff wells and 1 steam flooding well,and they all achieved a good water-controlling and oil-increasing effect.