新疆油田二元复合驱高黏采出液降黏技术

Viscosity-reducing technology for high-viscosity produced fluid in binary combination flooding in Xinjiang Oilfield

在新疆油田七中区化学驱油现场试验中,部分采油井出现了高表观黏度(4000 mPa·s)的乳状液,放置几天均不破乳降黏,严重影响采油与运输。为降低乳状液的表观黏度,研究了添加破乳剂、升温法、超声法及加盐法对乳状液表观黏度的影响,总结筛选出最优的降黏方法。结果表明:季铵盐类破乳剂对该种乳状液降黏效果很差;温度对乳状液的流变性影响很大,相同剪切率下,温度越高,乳状液的表观黏度越小;超声能显著降低乳状液的表观黏度;Nacl质量浓度为10000 mg/L、乳状液与污水体积比为5:5时,降黏效果最好。研究成果对化学驱高黏采出液集输及后续处理具有重要指导意义。

In the field chemical flooding test of the Qizhong District of Xinjiang Oilfield,emulsion with high apparent viscosity(4000 mPa·s)was found in some well,without demulsification and viscosity reduction after placement in several days,which affected the oil production and transportation seriously.In order to reduce the apparent viscosity of the emulsion,the effects of demulsifier,heating,ultrasound and salt on the apparent viscosity of the emulsion were studied to summarize the optimal method for viscosity reduction.According to the study results,quaternary ammonium salt demulsifier has very poor effect on viscosity reduction of the emulsion.Temperature has a great effect on rheological property of the emulsion.With same shear rate,the higher the temperature,the lower the apparent viscosity of the emulsion is.The ultrasound can reduce the apparent viscosity of the emulsion significantly,and the viscosity reduction effect is best in the condition that the salt content is 10000 mg/L and the volume ratio of the emulsion and the wastewater is 5:5.Generally,the above research results are of important guiding significance to the gathering and transportation of chemical flooding highviscosity produced fluid and its subsequent treatment.