井下雾化排液短节数值模拟及影响因素分析

Numerical Simulation and Analysis of Influencing Factors of Downhole Atomization and Discharge Tool

现有文献对井下雾化排液短节的雾化原理与设计方法研究还不够充分。为此,针对新疆油田应用的井下雾化排液短节,基于计算流体力学相关方法建立了数值试验模型,对短节雾化原理与参数影响规律进行了模拟研究。研究结果表明:气液混流经切向入口进入并起旋分离,经引流体和气流通道至喷嘴处加速喷出,主喷嘴处液膜受剪切破碎成雾滴,副喷嘴处高速气流辅助雾化;选取日产气量、入口压力和喷嘴当量直径3个关键参数进行了计算分析,日产气量与喷嘴压降呈正相关趋势,入口压力、喷嘴当量直径与喷嘴压降呈负相关趋势。研究结果及提出的“一井一策”的短节设计方法对井下雾化排液采气技术的广泛应用具有理论指导意义。

The existing reported studies are not sufficient on principle and design method of underground atomization.To address the problem,taking the downhole atomization and liquid discharge tool applied in Xinjiang Oilfield for case study,a numerical test model was established based on the computational fluid dynamics methods.The working principle,the influence of key parameters and the design method of the atomization and liquid discharge tool were studied.The results show that the gas-liquid mixed flow enters through the tangential inlet and swirls to separate,and is accelerated at the nozzle through the fluid and air flow channel.The liquid film at the main nozzle is sheared and broken into droplets,and the high-speed air flow at the auxiliary nozzle enhances the mist.Three key parameters of daily gas production,inlet pressure and nozzle equivalent diameter were selected for calculation and analysis.Daily gas production and nozzle pressure drop showed a positive correlation trend.The inlet pressure and nozzle equivalent diameter showed a negative correlation trend with the nozzle pressure drop.The proposed“one well,one strategy”tool design method has theoretical guiding significance for the wide application of downhole atomization liquid discharge technology.