硫酸钡锶垢清垢剂的制备与性能评价

Preparation and Property of Sulfate Scale Removing Agent

唐泽玮 朱方辉 李明星 刘宁 董俊

TANG Zewei ZHU Fanghui LI Mingxing LIU Ning DONG Jun

为了消除硫酸钡锶垢对地层的堵塞，以二乙烯三胺五乙酸、二乙烯三胺五乙酸五钠、乙二胺四乙酸、氨基三甲叉磷酸、乙二胺四甲叉磷酸钠、二乙烯三胺五甲叉膦酸多种螯合剂为主剂，合成了浅黄色的硫酸盐清垢剂，研究了该清垢剂的清垢效率、岩心渗透率恢复率及腐蚀性。结果表明，该清垢剂可有效清除硫酸盐垢，使结垢岩心渗透率恢复。60 ℃条件下，8%～10%清垢液的清垢效率约80%；升高温度可提高清垢效率，温度从20 ℃升至80 ℃时，清垢效率从80.52%增至85.65%；随清垢时间延长，清垢效率增大并逐渐稳定，12 h 时的清垢效率达到83.0%；在30～70 ℃下，水驱后注入10 PV 100 mg/L 清垢液，结垢岩心渗透率恢复至原始渗透率的85.56%～92.59%。该清垢剂对油套管的腐蚀性小，25 ℃和60 ℃下，10%清垢液对油套管的腐蚀速率分别为0.0404 和0.1014 mm/a，低于常用酸液体系，有利于安全施工。图3 表3 参12

In order to remove the formation plugging caused by barium and strontium sulfate precipitation，a buff sulfate scale removing agent was synthesized by various chelating agents， such as diethylene triamine pentacetic acid， diethylene triaminepentaacetic acid pentasodium，ethylene diamine tetraacetic acid，amino trimethylene phosphonic acid，ethylene diamine tetra（methylene phosphonic acid） sodium and diethylene triaminepenta（methylene phosphonic） acid. The cleaning scale efficiency，core permeability recovery and corrosivity were evaluated. The results showed that the scale remover could effectively remove sulfate scale and recover the permeability of fouling core. The cleaning scale efficiency of 8%—10％ cleaning scale solution was about 80％ at 60℃. Higher temperature increased cleaning scale efficiency. When the temperature rose from 20℃ to 80℃，the cleaning scale efficiency increased from 80.52% to 85.65%. With prolonging time of cleaning scale，the cleaning scale efficiency went up and got stably to 83.0% after 12 hrs reaction. The core permeability could restore 85.56%—92.59% when 10 PV cleaning scale solution with 100 mg/L was injected at 30—70℃ after water flooding. The scale remover had low corrosion to tubing and casing. At 25℃ and 60℃，the corrosive rate of 10% cleaning scale solution to casing and tubing was 0.0404 mm/a and 0.1014 mm/a，respectively，which was much lower than that of common acid solution and was helpful to safe on-site operation.