A plugging agent for profile control of high temperature and high salinity reservoirs was developed by adding partially hydrolyzed polyacrylonitrile(HPAN) and modified silica to partially hydrolyzed polyacrylamide(HPAM) to improve the heat resistance and salt tolerance of crosslinked polymer gel. The properties of the developed gel system were investigated,and this system was applied to high permeability reservoirs in Qing Zu oil extraction area of Hu Qing oilfield. The results showed that the developed gel system formula was 0.6%(w) HPAM+4%(w) HPAN+3%(w) modified superfine SiO2+1.0%(w) urotropine+1.0%(w) resorcinol. The gel system was placed for 90 d under the conditions of 120 ℃ and salinity 20×104mg/L and exhibited little strength change without glue breaking hydration phenomenon. The stemming ratios of the gel system were all above 92% in high,medium and low permeability single pipe sand-filled cores. The plugging agent was applied 4 times to a high water bearing well group in Qing Zu oil extraction area of Hu Qing oilfield and took effect in 9 out of 10 corresponding oil wells with accumulative enhanced production of oil being 1 400 t,average water content being decreased by 1.8%(w). Moreover,the effective period of the plugging agent was up to 9 months.%通过在部分水解聚丙烯胺(HPAM)中加入部分水解聚丙烯腈(HPAN)和改性二氧化硅提高交联聚合物凝胶的耐温抗盐性能,研制了可用于高温高盐油藏调剖的堵剂,考察了所研制凝胶体系的性能,并将其用于胡庆油田庆祖采油区中高渗油藏.实验结果表明,所研制凝胶体系的配方为:0.6%(w)HPAM +4%(w)HPAN +3%(w)改性超细SiO2+ 1.0%(w)乌洛托品+1.0%(w)间苯二酚.该凝胶体系120 ℃、矿化度为20×104mg/L条件下,静置90 d,强度变化小,无破胶水化现象;在高、中、低3种渗透率单管填砂岩心中,封堵率均超过92%.该堵剂应用于胡庆油田庆祖采油区高含水井组4井次,10口对应油井中9口见效,累计增油1 400 t,平均含水率下降1.8%(w),有效期达9个月.
展开▼
