闭式热流体循环井筒温度分布规律研究

Temperature Distribution in Closed Wellbore with Hot Fluid Circulation

为了合理配备闭式热流体循环降黏设备、设定循环参数,利用传热学相关理论,建立了闭式热流体循环井加热段和非加热段的井筒温度场模型,结合模型的定解条件,对井筒压力和温度进行耦合求得数值解。利用建立的模型对采用闭式热流体循环降黏4口井产出液和上返液的井口温度进行了预测,并探讨了生产参数和循环参数对井筒加热效果的影响,结果表明:预测的产出液和上返液的井口温度与实测结果相比平均相对误差分别为3.08%和1.38%,符合工程要求;产出液量每增加1t/d,产出液温度降低0.134 5℃;含水率每升高10%,产出液温度降低0.161℃;随注入循环量的增大和注入温度的升高,产出液温度升高,但注入温度对产出液温度影响较大。利用闭式热流体循环井筒温度场模型分析井筒温度场,可以为闭式热流体循环降黏设计提供依据。

To configure the closed equipment with hot fluid circulation and set its circulation parame-ters properly ,the temperature field model was established for heating and non-heating sections of a closed wellbore with hot fluid circulation on the basis of relevant heat transfer theories .Under the condition of definite solution ,the model was used to determine the coupling values of pressure and temperature in well-bore .Moreover ,the model was also used to predict the wellhead temperature of fluids produced and re-turned in four closed wells in which hot fluids were circulated ,and the influences of production and circula-tion parameters on wellbore heating were discussed .The results showed that the average error of predicted wellhead temperature of fluids produced and returned was 3.08% and 1.38% respectively ,compared with the measured values ,w hich meet the engineering requirements ;the temperature of fluid produced declined by 0.134 5 ℃ if fluid volume increased one ton per day ,and declined 0.161 ℃ if water cut increased by 10% ;and the temperature of produced fluids rises with the increase of circulation rate and injecting temperature ,which is the main factor to affect the heating effects .The method can provide basis for the design of the hot fluid circulation in closed wellbore to lower viscosity of produced fluids by modeling the temperature field .