油气叠合区气田废水回注油层配伍性研究

Study on the compatibility of oil reservoir reinjection in gas field wastewater in oil-gas superposition area

以鄂尔多斯某油气田叠合区气田和油田废水各代表性站点水质检测分析结果为基础,进行了气田与油田废水结垢趋势预测、静态配伍性研究,结果表明:在25℃与60℃下,QT-1与YT-1的不同比例混配下,结垢趋势均小于QT-2与YT-1、QT-3与YT-1、YL-2与YT-1和YL-1与YT-1。QT-1与YT-1在1∶9混配,QT-2与YT-1在5∶5混配,QT-3与YT-1在1∶9混配,YL-1与YT-1在5∶5混配,YL-2与YT-1在1∶9混配时失钙当量最低,结垢趋势最小。根据油气田废水配伍性实验结果,确定配伍性最优的QT-1与YT-1,研究其按比例混合后回注地层的配伍性实验,其结果为单注对地层伤害率为14%,合注对地层伤害率为46.2%。

Based on the results of water quality testing and analysis of water quality of representative stations,the results showed that the scaling trend of QT-1 and YT-1 was smaller than that of QT-2 and YT-1,QT-3 and YT-1,YL-2 and YT-1,and YL-1 and YT-1 at 25°C and 60°C.QT-1 and YT-1 were mixed at 1∶9,QT-2 and YT-1 were mixed at 5∶5,QT-3 and YT-1 were mixed at 1∶9,YL-1 and YT-1 were mixed at 5∶5,and YL-2 and YT-1 were mixed at 1∶9 when the calcium equivalent was the lowest and the scaling tendency was the smallest.According to the results of the compatibility experiment of wastewater from oil and gas field,QT-1 and YT-1 with the best compatibility were determined,and the compatibility experiment of reinjection formation after proportional mixing was studied,and the result was that the damage rate of single injection to the formation was 14%,and the damage rate of combined injection to the formation was 46.2%.