丙烯酰胺/2-丙烯酰胺-2-甲基丙磺酸共聚物水解及成胶规律

Hydrolysis and gelation study of acrylamide/2-acrylamide-2-methylpropane sulfonic acid copolymer

利用丙烯酰胺(AM)/2-丙烯酰胺-2-甲基丙磺酸(AMPS)共聚物、纳米硅颗粒、乙酸铬交联剂等原料制备了AM/AMPS共聚物铬冻胶堵剂,分析了AMPS单体含量和纳米硅颗粒用量对共聚物水解及铬冻胶体系性能的影响。实验结果表明,随AMPS单体含量的提高,共聚物水解速度降低,铬冻胶体系成胶时间逐渐延长;纳米硅颗粒对共聚物水解基本没有影响,但可提高冻胶强度和长期稳定性。90℃下AM/AMPS共聚物铬冻胶堵剂最优配方为:0.8%(w)AM/AMPS共聚物聚合物(AMPS单体含量为50%(x))、0.3%(w)乙酸铬、0.1%(w)硫脲、0.6%(w)纳米硅颗粒。该配方的铬冻胶堵剂的成胶时间为21 h,可满足现场作业对成胶时间的需求,成胶后弹性模量大于16 Pa,突破压力梯度可达2 MPa/m以上,属于高强度冻胶,封堵能力强。

Acrylamide(AM)/2-acrylamide-2-methylpropanesulfonic acid(AMPS)copolymer chromium gel plugging agent was prepared with AM/AMPS copolymer,nano silicon particles,chromium acetate crosslinker and other auxilaries.The effects of AMPS monomer content and nano silicon dosage on the hydrolysis of copolymer and gelation properties of chromium gel were evaluated.The results showed that with the increase of AMPS monomer content,the hydrolysis rate of copolymer decreased and the gelation time of chromium gel system gradually increased.Nano silicon had little effect on the hydrolysis rate and gelation time,but could improve gel strength and long-term stability.At 90℃,the best formulation of chromium gel plugging agent was as follows:0.8%(w)polymer(50%(x)AMPS in copolymer),0.3%(w)chromic acetate,0.1%(w)thiocarbamide and 0.6%(w)nano silicon.The gelation time was 21 h,which could meet the requirements in field operation.The elastic modulus was greater than 16 Pa and the breakthrough pressure gradient could exceed 2 MPa/m,suggesting high strength and strong plugging ability.