永平油田稠油自发乳化降粘剂的筛选及驱油效果评价

针对永平油田稠油粘度大、油层厚度薄、原始含油饱和度低及热采投产后产油量低的现状,筛选出一种能使稠油在地层中发生自发乳化的降粘剂,使稠油以较低粘度的乳状液被采出,从而提高稠油的采收率。针对不同乳化降粘剂对永平油田稠油的乳化效果评价结果表明,自发乳化降粘剂NS在质量分数为2%、温度为45℃的条件下,可将油水界面张力降至10-3mN/m数量级以下,并可完全自发乳化等体积的永平油田稠油,降粘率达99.74%。NS自发乳化驱油实验结果表明,经过后续水驱后,自发乳化驱的采收率在水驱基础上提高了38.18%。

Screening of emulsified viscosity reducer on heavy crude oil and effect evaluation of oil displacement,Yongping oilfield in Jilin

An emulsion with low viscosity comes into being from two immiscible phases of oil and water by the spontaneous emulsi-fication of surfactant,which can be used to reduce the viscosity of heavy oil.In view of the situation of low production of thermal heavy oil recovery in Yongping oilfield of Jilin Province due to the characteristics of high viscosity for heavy oil,thin reservoir and low initial oil saturation.A formula of emulsified viscosity reducer which can make heavy oil self-emulsified in stratum is developed in order to reduce the oil viscosity and improve the heavy oil recovery in Yongping oilfield.The behaviors of spontaneous emulsification of the heavy oil in Yongping oilfield are studied by Brookfield DV-II viscometer,TX-500C interfacial tensiometer and microscope.The results show that the viscosity of equal volume heavy oil in Yongping oilfield can be decreased by 99.74% and the interfacial tension between oil and water is dropped to 10-3 mN/m under the performance of emulsified viscosity reducer (NS) with concentration of 2wt% and temperature of 45?.Flooding experiment test indicates that the final oil displacement efficiency may be increased by 38.18% and remarkable performance on heavy oil recovery may be achieved.