东辛油田稠油举升井筒保温对策研究及现场试验

稠油在井筒举升过程中,由于热损失造成温度下降,致使其黏度迅速增大,举升负荷较大。因此,研究稠油举升中的井筒保温对策具有现实意义。基于传热学的基本原理,采用计算稠油井井筒温度场的Hansan模型,以东辛油田Y12X2X3井为例对井筒温度分布进行了计算分析,并对影响稠油井井筒温度的油管类型、油管长度和产液量等3项参数进行了优化,提出了采用长度1 000 m的D级隔热油管和普通油管组合、产液量由11 m3/d提高到20 m3/d的井筒保温措施。现场试验显示,井口温度由调整前的20.5℃升高至41.5℃,井深1 000 m以浅井段原油黏度大幅度降低,原油流动性增强,有杆泵充满程度增加,泵效提高了47%。研究结果表明,采用稠油井筒温度场计算模型能准确描述井筒温度的分布情况,并能有针对性地制订稠油井井筒保温措施。 

Development and Application of Borehole Insulation Techniques for the Development of Heavy Oil Production in the Dongxin Oilfield

Due to thermal loss and temperature drop during oil lifting in the wellbore, the viscosities of heavy oil may increase rapidly and so will the lifting loads. Accordingly, it is important to develop effective insulation techniques for borehole to enhance productivity of heavy oil. The Hansan mathematical model for calculating the heavy oil wellbore temperature was established based on the theories of thermal transmission. The wellbore temperature distribution in Well Y12X2X3 was calculated and analyzed. In addition, the liquid-producing capacity, the type and length of insulation tubing were analyzed and optimized as main factors of wellbore temperature distribution. Reasonable wellbore heat preservation measures included choosing insulated tubing which length with a length of 1, 000 m and increasing the fluid volume from 11 m3/d to 20 m3/d. Field application showed that the wellbore temperature was enhanced from 20.5℃ to 41.5℃, and the viscosity of crude oil above a depth of 1, 000 m was greatly reduced. Eventually, the fluidity of oil as well as the filling level of the rod pump were also increased while the pumping efficiency increased by 47%. The results showed that the mathematical model for calculating the heavy oil wellbore temperature could describe the wellbore temperature accurately and the resulting effective wellbore insulation measures could be followed to enhance heavy oil productivity.