Wang Jinyu, Ran Dongsheng, Lu Hongsheng, Zhang Jiaping, Wu Yang
Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, Chengdu 610500, P. R. China.
Engineering Research Center of Oilfield Chemistry, Ministry of Education, Chengdu 610500, P. R. China.
Langmuir. 2024 Jul 17. doi: 10.1021/acs.langmuir.4c01867.
The increasing exploitation of fossil resources needs to shift people's attention to developing unconventional reservoir resources. Polyacrylamide-based emulsion drag reducers can effectively reduce the turbulence of fracturing fluid and improve oil recovery, but their release effect is poor, which limits their practical application. Here, we constructed a pH-responsive inverse polymer emulsion of poly(acrylamide-2-acrylamido-2-methylpropanesulfonic acid). Interestingly, HOA/Tween 80 exhibits remarkable pH-responsive behavior, which enables the monomer emulsion to change the type of emulsion under pH stimulation. Our results propose that the P(AM-AMPS) polymer emulsion is eluted with the same aqueous phase as the W/O P(AM-AMPS) polymer emulsion, thereby achieving the effect of drag reduction. P(AM-AMPS) can be rapidly released from the inverse polymer emulsion within 70 s upon pH stimulation, the drag reduction rate of which was 60.4%. Obviously, the inverse polymer emulsion prepared by a pH-responsive surfactant not only has good stability but also can achieve rapid release of the polymer upon pH stimulation, which supplies an interesting indication to explain why a balance exists between the stability of the emulsion and release of P(AM-AMPS).
对化石资源的不断开采需要将人们的注意力转移到开发非常规油藏资源上。基于聚丙烯酰胺的乳液减阻剂能有效降低压裂液的湍流并提高原油采收率，但其释放效果不佳，这限制了它们的实际应用。在此，我们构建了一种聚（丙烯酰胺 - 2 - 丙烯酰胺基 - 2 - 甲基丙烷磺酸）的pH响应型反相聚合物乳液。有趣的是，HOA/Tween 80表现出显著的pH响应行为，这使得单体乳液在pH刺激下能够改变乳液类型。我们的结果表明，P（AM - AMPS）聚合物乳液与W/O型P（AM - AMPS）聚合物乳液在相同水相中被洗脱，从而实现减阻效果。在pH刺激下，P（AM - AMPS）可在70秒内从反相聚合物乳液中快速释放，其减阻率为60.4%。显然，由pH响应型表面活性剂制备的反相聚合物乳液不仅具有良好的稳定性，而且在pH刺激下能够实现聚合物的快速释放，这为解释乳液稳定性与P（AM - AMPS）释放之间为何存在平衡提供了一个有趣的线索。
