国家青年科学基金“稠油火烧油层过程中二次点火热化学反应微观机理研究”（52004259）；南海西部油田上产2000万方关键技术研究（编号：CNOOC-KJ 135 ZDXM 38 ZJ 01 ZJ）。
China University of GeosciencesWuhan Wuhan Hubei
针对高黏土疏松低渗砂岩油藏注水过程中微粒运移堵塞储层孔喉导致注水压力高的难题,通过室内实验优选出了一种中性型梯度防堵体系,低速梯度防堵体系：0.5 %KCl黏土稳定剂,高速梯度防堵体系：0.2 % KCl+0.3%有机阳离子黏土稳定剂。考察了梯度防堵体系的防膨性、驱替过程中岩心压力和渗透率变化。结果表明,该体系防膨率超过91 %,与空白生产水驱替对比,低速下,经防堵体系处理后,压力增长倍数由5.41降为2.03,渗透率保留率由18.49%提高到49.15%；在高速下,经防堵体系处理后,岩心渗透率逐渐恢复,当转生产水驱替8PV后,渗透率保留率由10.56%提高至91.58%,压力增长倍数由9.47降为3.28,并持续降低。该防堵体系为中性,为低渗透油藏的超前绿色注水高效开发提供了有力支撑。图9表3参19
Aiming at the problem of high injection pressure caused by particle migration blocking the reservoir pore throat in the process of water injection in high clay loose and low permeability sandstone reservoir, a neutral gradient anti plugging system was optimized through laboratory experiments. The low-speed gradient anti plugging system is 0.5% KCl clay stabilizer, and the high-speed gradient anti plugging system is 0.2% KCl + 0.3% organic cationic clay stabilizer. The anti-swelling property of gradient anti plugging system and the changes of core pressure and permeability during displacement were investigated. The results showed that the anti-swelling rate of the system was more than 91%. Compared with the blank production water displacement, at low speed, after being treated by the anti-plugging system, the pressure growth multiple was reduced from 5.41 to 2.03, and the permeability retention rate was increased from 18.49% to 49.15%; At high speed, after being treated by the anti-plugging system, the core permeability gradually recovered. When 8PV was replaced by production water, the permeability retention rate increased from 10.56% to 91.58%, and the pressure growth multiple decreased from 9.47 to 3.28. The plugging prevention system is neutral, which provides a strong support for the advanced green water injection and efficient development of low permeability reservoirs.