樊学地区注入水与产层水的配伍性及注水处理工艺

Compatibility of Injection Water and Formation Water and Treatment Process in Fanxue Area

王梓民 刘 亮 吕 雷 张淑侠 张世君

WANG Zimin LIU Liang Lü Lei ZHANG Shuxia ZHANG Shijun

针对延长石油樊学地区注入水与产层水混合结垢严重的问题， 通过分析水样离子组成和配伍性， 预测了混注水结垢趋势， 确定了注水处理工艺， 并进行了岩心伤害实验。结果表明： 产层水矿化度在 104 mg/L数量级， 其中钡锶离子质量浓度高达 1000 mg/L， 注入水中的硫酸根离子质量浓度约 1000 mg/L。同层回注时， 控制硫酸根浓度是水处理工艺的关键。当硫酸根质量浓度低于 100 mg/L时， 不会产生硫酸锶沉淀； 当硫酸根质量浓度高于1 mg/L时， 会形成硫酸钡垢。采用预混合+沉淀剂+阻垢剂联合处理工艺， 可将硫酸根浓度降至 50 mg/L以下， 再加入 40 mg/L的阻垢剂即可使混注水达到要求。处理后混注水对岩心的伤害率为 15%。图2表 3参 15

Scale formed seriously when formation water and injection water mixed together for water flooding in Fanxue area of Yanchang oilfield. Water treatment technology was determined after ion content detection，compatibility and scaling tendency prediction of mixed injection water were studied. Then core damage experiment was done. The results showed that the salinity of formation water was as high as 104 mg/L and the concentration of barium and strontium ions was about 1000 mg/L. The concentration of sulfate was about 1000 mg/L in injection water. The critical step was how to control sulfate concentration during the same formation layer reinjection process. Strontium sulfate precipitate did not form if sulfate concentration was less than 100 mg/L， while barium sulfate precipitate appeared when sulfate concentration was greater than 1 mg/L. Use of the precipitant，scale inhibitor and a pre-mixing combined treatment process could improve the compatibility significantly，and the concentration of sulfate was less than 50 mg/L. The mixed water met the requirement of injecting water standard if 40 mg/L inhibitor was added. The core damage rate of the mixed water was 15% correspondingly.

10.19346/j.cnki.1000-4092.2016.06.015