Prediction of Critical Gas Velocity of Liquid Unloading for Entire Well Deviation
Prediction of Critical Gas Velocity of Liquid Unloading for Entire Well Deviation
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DOI：
10.2523/iptc-17846-ms
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
Jeff C. H. Li;Fahad Almudairis;Hong-quan Zhang
中科院分区：
文献类型：
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作者：
Jeff C. H. Li;Fahad Almudairis;Hong-quan Zhang
注液是成熟气井中常见的生产问题。由于地层压力降低，气体流速也随之降低，气体动能无法将液相完全提至地表。液体开始在井底积聚，这增加了储层的背压。这反映在液体和气体产量的波动中。与此同时，它会显著降低产量，并最终杀死油井。正确预测井开始加载时的临界气速对作业者来说非常重要，因为他们可以采取适当的措施来防止液体加载并延长井的生产寿命。过去，大多数关于液体加载的研究都集中在直井上。直到最近，人们才对斜井和水平井的液载问题进行了一些研究。迄今为止，关于如何在大斜角范围内预测临界气速的研究还很少。事实上，不同的研究人员得出了相互矛盾的结论。本文利用已发表的文献资料，建立了临界气速数据库。建立了一个新的模型，并用实验数据进行了验证。讨论了前人研究和建模的不足之处。
Liquid loading is a common production problem in mature gas wells. As the formation pressure decreases and gas flow rate also decreases, the gas kinetic energy is unable to lift the liquid phase completely to the surface. Liquid starts to accumulate at the bottom of the well, which increases the back pressure of the reservoir. This is reflected in a fluctuated production of liquid and gas rates. At the same time, it significantly reduces the production rate and eventually kills the well. Correct prediction of critical gas velocity at which the well starts to load is very important to the operators since they could take appropriate measures to prevent liquid loading and extend the well production life. In the past, most studies on liquid loading focused on vertical wells. only recently have a few studies been conducted to deal with the liquid loading for deviated and horizontal wells. To date, there are few published studies discussing how to predict the critical gas velocity across a wide deviation angle range. In fact, there are contradictory conclusions made by different researchers. In this paper a database related to the critical gas velocity is compiled with data from published literature. A new model is developed and evaluated with the experimental data. The gaps in the previous studies and modeling are also discussed.