岐口17-2油田清水污水混注配伍性实验研究

Experimental research on compatibility of water and sewage mixed injection for reservoir flooding in QK17-2 Oil Field

清水污水混注是海上中高含水油田普遍采用的注水开发方式。岐口17-2油田自2009年6月实施清水污水混注以来,注入压力逐渐升高,酸化有效期由注清水期间的9个月以上降至3个月以下。通过清水污水配伍性实验,研究了混注后水质的变化特征。结果表明:清水污水不同比例混合有结碳酸钙垢倾向,混合水样中钙离子浓度降低,悬浮物浓度升高,清水与污水存在不配伍;不配伍程度随污水比例增大、温度升高、时间延长有加剧趋势。

Water and sewage mixed injection for reservoir flooding is commonly used in offshore oilfield with middle and high water cut. Since June 2009 the operation of water ＆ sewage mixed injection in QK17-2 oil field, the acidification valid period from 9 months down to 3 months. Experiment research on compatibility of the produced water and the fresh water was conducted to analyze the change of injection water quality after mixing. The results show that： the mixing liquid has certain calcium carbonate scaling tendency with different proportion of fresh and produced water. And the calcium ion concentration decreased while concentration of suspended solids increased in the mixed fluid. The compatibility experimental results show that sewage water and fresh water is slight non-compat- ibility, and the degree of compatibility has accelerated trend with increasing of produced water proportion, temperature increment and the mix-time extension.