无氧条件下聚合物溶液黏度的测试

Viscosity Measurements for HPAM Solution without Dissolved Oxygen

受空气中氧的作用,大庆油田清水溶解、污水稀释聚合物溶液黏度的注入井口测试值偏低。研制了井口密闭取样瓶和黏度计隔离罩,建立了一套密闭取样和隔氧黏度测试方法。室内实验结果表明,有氧条件下黏度测定值受溶液中Fe2+的影响很大,无氧条件可大大减轻Fe2+的影响。现场取样测试结果表明,以现配聚合物溶液黏度值为基准,无氧条件下17口井的井口黏度测试值平均误差、最大误差、最小误差分别为12.6%、30.4%、0.4%;有氧条件下分别为50.1%、72.8%、24.3%。

Rather low viscosity determinations are often obtained for wellhead polymer flooding solutions,prepared by dissolving powdered polymer in fresh water and diluting with produced water.Special hermetic sampling bottles and viscosimeter housing are designed and manufactured and a systematic oxygen-free procedure of sampling and viscosity determination is established.In laboratory experiments it is found that the viscosity values determined in open air are highly influenced by Fe2＋ in the polymer solution and oxygen-free conditions significantly reduce the bad effects of Fe2＋.Field results show that for wellhead polymer solution samples taken from 17 injection wells,the average、the biggest,and the lowest values of relative error of oxygen-free viscosity determinations are of 12.6%,30.4%,and 0.4%,respectively,on the basis of the viscosity values of polymer solutions as prepared in contrast with 50.1%,72.8%,and 24.3%,respectively,for open-air viscosity determinations.