渤海稠油物性特征分析及开发措施研究

ANALYSIS OF PHYSICAL PROPERTIES OF HEAVY OIL IN BOHAI SEA AND STUDY ON DE⁃VELOPMENT MEASURES

针对渤海稠油黏度大、流动性差、开采难度大等问题,从稠油物性特征分析着手,研究了渤海油田5种稠油族组分含量与黏度的关系、研究了温度对稠油黏度和屈服应力值的影响,并研究了稠油黏度对开发措施效果的影响。结果表明:渤海稠油黏度随着饱和分和芳香分含量的增加而呈指数函数关系降低随着胶质沥青质含量的增加呈指数函数关系升高;随着温度的升高,稠油的黏度和屈服值逐渐降低,普通稠油的屈服应力曲线拐点温度为50~60℃,特稠油拐点温度为70~80℃;对于黏度低于500 mPa·s的稠油,适宜进行中低温水驱来提高采收效果;黏度范围在1000 mPa·s以上的原油可进行注热开采,对B-2原油,建议注热温度应不低于200℃;黏度在5000 mPa·s以上的原油,300℃热采相比60℃水驱驱油效率提升的幅度可达到20%以上,建议采用300℃高温热采方式进行开发。

Aiming at the problems of high viscosity,poor fluidity and difficult exploitation of heavy oil in Bohai Sea,the phys⁃ical properties of five kinds of heavy oil in Bohai Oilfield are studied.The relationship between the content of heavy oil group components and viscosity,the influence of temperature on viscosity and yield stress value of heavy oil is analyzed,and the in⁃fluence of viscosity on the effect of development measures is studied.The results show that the viscosity of heavy oil in Bohai Sea decreases exponentially with the increase of saturation and aromatic content,and increases exponentially with the in⁃crease of gum asphaltene content.With the increase of temperature,the viscosity and yield value of heavy oil gradually de⁃crease,and the inflection point temperature of yield stress curve of common heavy oil is between 50-60℃,and the inflection point temperature of extra heavy oil is between 70-80℃.For heavy oil with viscosity less than 500 mPa·s,medium tempera⁃ture water flooding is suitable to improve recovery effect;crude oil with viscosity over 1000 mPa·s can be exploited by heat injection.For B-2 crude oil,it is suggested that heat injection temperature should not be less than 200℃.For crude oil with viscosity over 5000 mPa·s,thermal recovery at 300℃can increase recovery by more than 20%compared with water flooding at 60℃,and it is suggested that high temperature thermal recovery at 300℃should be adopted for development.