注过热蒸汽井筒沿程参数及加热半径计算模型

Calculation model of on-way parameters and heating radius in the superheated steam injection wellbore

过热蒸汽是单相的气体,以气液两相流理论为基础的普通蒸汽热损失计算模型对其不再适用。通过引入过热蒸汽PVT数据体,建立了注过热蒸汽井筒沿程参数计算模型。在一定假设的基础上,理论推导出了过热蒸汽带面积、加热带半径等的数学表达式。利用蒸汽沿程参数计算模型对肯基亚克油田盐上油藏X16井不同状态水蒸汽的沿程变化进行了计算,结果表明:计算结果与现场测试结果对应较好。分析认为,随着热量的传递,过热蒸汽的温度变化较大,压力变化也大于普通蒸汽,到达井底的蒸汽干度特别高,其热焓值比注普通蒸汽有大幅度提高,加热半径也有所增加。

As superheated steam is single-phase gas,the ordinary steam heat loss calculation model based on two-phase flow theories isn＇t applicable.With the introduction of the PVT data sets,this article builds a calculation model of on-way parameters in the superheated steam injection wellbore.Based on some basic hypothesis,the mathematic expressions of superheated steam heating area and heating radius are presented.The calculated results and measured data for on-way change of steams in Well X16 of the Kenneyak Oilfield fit well with the field test results.The analysis shows that,with the heat transfer,the temperature of the superheated steam varies greatly,its pressure varies greater than ordinary steam,the steam quality is high when reaching the bottom hole,the steam enthalpy value is much higher,and the heating radius is bigger than that of ordinary steam.