两性离子抑制剂的合成及性能

以二甲基二烯丙基氯化铵（DMDAAC）、甲基烯丙醇（MP）以及2-丙烯酰胺基-2-甲基丙磺酸（AMPS） 3种单体为原料，采用水溶液聚合法合成出了一种低分子量、线型、两性离子共聚物，并采用FTIR、SEM、乌式黏度计、凝胶色谱仪对其进行了表征。考察了引发剂的加量、单体的总浓度、单体的摩尔比、反应的温度、反应时间对其抑制性能的影响。结果表明最佳反应条件为：引发剂为4%，单体总质量分数为30%，单体间摩尔比率为AMPS∶DMDAAC∶MP=4∶3∶4，反应温度为65℃，反应时间为7h。采用线性膨胀率、滚动回收率考察了产物的抑制性，并与XY-27、SIAT、聚合醇进行了比较。结果表明共聚物的抑制性优于XY-27、SIAT和聚合醇。采用XRD、zeta电位从微观角度考察了其作用机理，结果表明：共聚物能够减小膨润土晶层间距，压缩其扩散双电层。将抑制剂加入钻井液体系，考察了体系的流变性、滤失性、抑制性，结果表明该抑制剂具有良好的配伍性和抑制性。

Synthesis and performance of a polyampholyte inhibitor

The polyampholyte inhibitor was synthesized with three monomers, namely, diallyl dimethyl ammonium chloride(DMDAAC), methyl allyl alcohol(MP) and 2-acrylamido-2-methyl propane sulfonic acid(AMPS), by means of aqueous solution polymerization. It was characterized by FTIR, SEM, Ubbelohde viscometer and GPC. It is a low molecular weight, linear and zwitterionic copolymer. The effects of initiator dosage, total monomer concentration, molar ratio of three monomers, reaction temperature and reaction time on the inhibition performance were investigated. The results showed that the optimum reaction conditions were determined as follows:4% ammonium persulfate initiator, 30% concentration monomer, the molar ratio of AMPS:DMDAAC:MP=4:3:4, 65℃ the reaction temperature and 7 hours reaction. The inhibition performance was evaluated by linear swelling experiment and rolling recovery rate, and compared with XY-27, SIAT and polymeric alcohol. The results indicated that the polyampholyte inhibitor had the best inhibitory effects. The microscopic mechanism was investigated by XRD and zeta potential,which showed that it can reduce the spacing of bentonite and compress the diffusion double electron layer. The performance of drilling fluid system with inhibitor was evaluated by rheological properties, filtration properties and rolling recovery, indicating that the inhibitor had good compatibility and strong inhibitory effects.