AM-AMPS-TAC polymers with different charge distribution are synthesized using acrylamide (AM), 2-acrylamido-2-methylpropanesulfonate (AMPS) and 3-acrylamidopropyl trimethylammonium (TAC) at different feed ratios by polymerization in solution. The salt-responsive behavior, reasons leading to salt-responsiveness, and effects of polymers molecular structure on salt-responsiveness are studied by laboratory experiments to find out the adaptability of the polymers. Rheology test under stepwise shear mode shows that the AM-AMPS-TAC polymers have salt responsiveness, and the closer the feeds of AMPS and ATC, the more significant the salt responsiveness will be. Conformation change of polymers molecular chain under salt stimulus is studied by turbidity test and micro-morphology analysis, and the responsive mechanism is further investigated by intrinsic viscosity test and copolymer composition analysis. Results indicate that the salt-responsive behavior of AM-AMPS-TAC polymers derives from the “curled to expanded” transition of chain conformation under salt stimulus, and this transition is led by the screening effect of salt which weakens polymers intramolecular ionic bond. Application in saturated saltwater drilling fluid shows that the AM₉₀-AMPS₅-TAC₅ polymer has the best salt-tolerance and temperature-tolerance when used together with fluid loss controller PAC-Lv. The drilling fluid saturated with NaCl can maintain stable viscosity, good dispersion and low fluid loss for long time under 150 °C.

使用丙烯酰胺（AM），2-丙烯酰胺基-2-甲基丙烷磺酸酯（AMPS）和3-丙烯酰胺基丙基三甲基铵（TAC），通过在溶液中聚合，合成具有不同电荷分布的AM-AMPS-TAC聚合物。通过实验室实验研究了盐响应行为，导致盐响应的原因以及聚合物分子结构对盐响应的影响，以发现聚合物的适应性。在逐步剪切模式下的流变测试表明，AM-AMPS-TAC聚合物具有盐响应性，AMPS和ATC的进料越近，盐响应性就越显着。通过浊度测试和微观形貌分析研究了盐刺激下聚合物分子链的构象变化，通过特性粘度测试和共聚物组成分析进一步研究了反应机理。结果表明，AM-AMPS-TAC聚合物的盐响应行为源自盐刺激下链构象的“卷曲到扩展”转变，而这种转变是由弱化聚合物分子内离子键的盐的筛选作用导致的。在饱和盐水钻井液中的应用表明AM₉₀ -AMPS ₅ -TAC ₅聚合物与失水量控制器PAC-Lv一起使用时，具有最佳的耐盐性和耐温性。在150°C的长时间下，用NaCl饱和的钻井液可以保持稳定的粘度，良好的分散性和低漏失率。