低渗水敏油藏黏土稳定剂KS-1的性能

Performance Properties of Clay Stabilizer KS-1 for Low Permeability and Water Sensitive Oil Reservoirs

胜利油区90％以上低渗砂岩油藏有不同程度的水敏性，其中42．1％属中强水敏。针对低渗水敏性油藏研发的黏土稳定剂KS-1，为齐聚物型有机聚季铵盐，相对分子质量适中，为3000～5000。该剂与胜利油区矿化度0．917～14．4g／L的各种注入水（清水和污水）配伍。使用气测渗透率3．2×10^-3～27．1×10^-3时的中等和强水敏储层岩心，以2％KCl溶液渗透率为基准，考察以5PVKS-1溶液处理后再注入30PV注入水及蒸馏水时的渗透率保留率，结果表明当KS-1质量分数≥0．68％时，保留率均〉90％，最高达99．5％，而岩心未经KS-1处理时保留率仅5．4％～64．3％；25℃和90℃下的实验结果相差很小；经KS-1处理的极强和中强水敏岩心中注入100PV蒸馏水时，渗透率保留率在90％以上，蒸馏水注入量达300Pv时在82％以上，表明KS-1抗冲刷能力强。KS-1质量分数为0．34％或KS-1溶液注入量为2PV时，黏土稳定效果差。图2表2参5。

Over 90% samples of tow permeability oil reservoirs in Shengli are water sensitive in different degree and 42.1% samples are of medium-strong water sensitivity. Clay stabilizer KS-1, developed for water sensitive oil reservoirs, is organic oligomeric polyammonium salts of medium molar mass in range 3000--5000. KS-1 is compatible with various flooding waters, fresh and recycled produced, of TSD in range 0. 917 - 14.4 g/L for Shengli reservoirs. Medium and strong water sensitive reservoir cores of gas perme- ability 3.2×10^-3 -27.1×10^-3μm^2 are pretreated by injecting 5 PV of KS-1 solution and then flooded with 30 PV of a recycled produced water or distilled water（DW） and the core permeability retention related to 2 % KC1 solution permeability are determined to be 〉90% and 99.5% in one case when≥0.68% KS-1 solution is used for pretreatments meanwhile a permeability retention of 5.4 -64,3 % is obtained for unpretreated cores; the experimental data determined at 25℃and 90℃ are not greatly different; the very strong and medium strong water sensitive cores pretreated by KS-1 have a permeability retention 〉90% and 〉82% after 100 and 300 PV of DW injected, which demonstrates high resistance of KS-1 against washing and erosion. The results of KS-1 pretreatments are poor when 0.34% KS-1 solution is used or 2 PV of KS-1 solution is injected.