【摘要】 积液气井连续管注氮排液过程中，为了优选注氮排量、注气深度、连续管尺寸及下入速度等参数，基于气液两相流动压降理论及临界携液模型，建立了连续管注氮排液算法模型，从临界注氮排量、井底压力、注氮泵压3个方面对注氮排液参数进行分析，研究了最佳注氮排量范围及排液参数对井底压力和注氮泵压的影响规律。研究结果表明：随着注氮排量的增加，满足临界携液的井筒段增大，对应的井底压力先降低后增大；增大注气点深度、减小连续管下入速度、减小连续管外径均可以获得更低的井底压力；积液黏度仅对泡状流等含连续液相的流型的压降影响较大，对雾状流等含连续气相流型的压降影响较小；连续管外径的改变对泵压的影响最为显著。研究结果可为连续管注氮排液参数的选择提供理论依据。更多还原

【Abstract】 During the operation of nitrogen injection and unloading by coiled tubing in gas wells with liquid accumulation, in order to optimize the parameters such as nitrogen injection displacement, gas injection depth, size of coiled tubing and running speed, based on the pressure drop theory and critical liquid carrying model of gas-liquid two-phase flow, an algorithm model of nitrogen injection and unloading by coiled tubing was established.The parameters of nitrogen injection and unloading such as critical nitrogen injection displacement, downhole pressure and nitrogen injection pump pressure were studied.The optimal range of nitrogen injection displacement was defined and the influences of unloading parameters on downhole pressure and nitrogen injection pump pressure were clarified.The study results show that, with the increase of nitrogen injection displacement, the wellbore interval meeting the critical liquid carrying capacity increases, and the corresponding bottom hole pressure decreases first and then increases.Bottom hole pressure can be reduced by increasing the depth of gas injection point, decreasing the running speed of coiled tubing and decreasing the size of coiled tubing.The viscosity of liquid accumulation only has a great influence on the pressure drop of the flow pattern with continuous liquid phase such as bubble flow, but has little influence on the pressure drop of the flow pattern with continuous gas phase such as mist flow.The change of coiled tubing size has the most significant effect on pump pressure.The results can provide a theoretical basis for selecting unloading parameters of nitrogen injection and unloading by coiled tubing.更多还原