产水凝析气井积液诊断研究

LIQUID-LOADING DIAGNOSIS OF WATER-PRODUCING CONDENSATE GAS WELL

在凝析气井中,当地层能量不足时,井筒中液体因无法排出而形成积液,导致井底压力增大,从而降低气井产能;更严重的情况可能会造成气井被压死,导致气井报废。因此,对产水凝析气井进行积液诊断至关重要。针对产水的凝析气井,以井底为连续排液的参考点,通过闪蒸计算得出凝析气井井底气油比,由此计算出井底凝析油产量,进一步计算油水混合物密度,分别带入Turner模型,Coleman模型,李闽模型进行分析计算,将不同模型计算的理论临界携液流量与气井实际产量进行对比分析,判断气井是否积液。诊断结果表明,Coleman模型和李闽模型诊断的准确率较高,Turner模型诊断的准确率相对较低。建议油田现场使用Coleman模型或李闽模型进行气井积液诊断。

In a condensate gas well, wellbore liquid loading caused by insufficient formation energy can lead to an increase of downhole pressure further resulting in a lower productivity. More seriously, it may cause well abandoned due to excessive well killing. Thus, it's so important to diagnose the liquid loading in water-producing condensate gas wells. This study takes the downhole as a reference point of continuous drainage, calculates the downhole gas-oil ratio by flashing, the downhole output of condensate oil, and the density of oil-water mixture. Subsequently, the calculated results are analyzed separately by Turner, Coleman and Limin models. And then, the theoretically critical flow rates of liquid carrying calculated by the models are compared with the actual output so as to determine the liquid loading. Results show that the diagnostic accuracy of Coleman and Limin is higher than that of Turner. It's suggested to use Coleman or Limin models for the field diagnosis.