Thermophysical properties estimation and performance analysis of superheated-steam injection in horizontal wells considering phase change
Thermophysical properties estimation and performance analysis of superheated-steam injection in horizontal wells considering phase change
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DOI：
10.1016/j.enconman.2015.04.029
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发表时间：
2015-07
影响因子：
10.4
通讯作者：
Haoxiang Gu;Linsong Cheng;Shijun Huang;Bing Bo;Yinguo Zhou;Zhongyi Xu
中科院分区：
文献类型：
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作者：
Haoxiang Gu;Linsong Cheng;Shijun Huang;Bing Bo;Yinguo Zhou;Zhongyi Xu
本文的目的是建立一个综合的热物性数学模型，分析水平井过热蒸汽注入的性能。本文首先根据质量和动量平衡原理建立了质量流量和压降的控制方程。更重要的是，考虑了过热蒸汽的相变行为。然后，根据井筒内的能量平衡，进一步推导出过热度和蒸汽质量的隐式方程。其次，采用迭代法求解数学模型，并给出了计算流程图。最后，通过与现场实测数据的对比验证了模型的有效性，详细分析了影响热物性剖面的重要因素。结果表明：当过热度一定时，过热蒸汽冷却为湿蒸汽后，质量流量下降较快；其次，要保证水平井趾段也能有效加热，注入速度不宜过慢。水平井筒同一位置的质量流量和过热度程度随着注入压力的增大而减小。最后发现，当储层渗透率较高或原油粘度较低时，质量流量和过热度迅速下降。
The objectives of this work are to establish a comprehensive mathematical model for estimating thermophysical properties and to analyze the performance of superheated-steam injection in horizontal wells. In this paper, governing equations for mass flow rate and pressure drop are firstly established according to mass and momentum balance principles. More importantly, phase change behavior of superheated steam is taken into account. Then, implicit equations for both the degree of superheat and steam quality are further derived based on energy balance in the wellbore. Next, the mathematical model is solved using an iterative technique and a calculation flowchart is provided. Finally, after the proposed model is validated by comparison with measured field data, the effects of some important factors on the profiles of thermophysical properties are analyzed in detail. The results indicate that for a given degree of superheat, the mass flow rate drops faster after superheated steam is cooled to wet steam. Secondly, to ensure that the toe section of horizontal well can also be heated effectively, the injection rate should not be too slow. Thirdly, the mass flow rate and the degree of superheat in the same position of horizontal wellbore decrease with injection pressure. Finally, it is found that when reservoir permeability is high or oil viscosity is low, the mass flow rate and the degree of superheat decline rapidly.