Shi Shuzhe, Han Guoqing, Zhong Ziyao, Li Zhun
The Research Institute of Petroleum Exploration and Development, Beijing 100083, China.
College of Petroleum Engineering, China University of Petroleum at Beijing, Beijing 102249, China.
ACS Omega. 2021 Jul 22;6(30):19458-19470. doi: 10.1021/acsomega.1c01563. eCollection 2021 Aug 3.
This work focuses on the two-phase slug flow in the curve pipe, which is very common in oil/gas wells. In terms of oil and gas production, the unstable slug flow may cause several problems and reduce production. In the present work, slug flow experiments were conducted in several curve pipes for varying inflow angles and gas-liquid velocity ratios. The real-time pressure was measured at the curve pipe using the Rosemount pressure gauges, and the liquid holdup was measured using the conductivity sensors, which were used to calculate the slug length. Then, we define the dimensionless slug length φ = / (the ratio of slug length to pipe diameter ), which can make the slug analysis free from the influence of different pipe diameters; φ is also used to analyze the change in the slug flow state. The experimental results show that the dimensionless slug length φ increases with the increase in the pipe curvature; φ first decreases and then increases with the increase in the inflow angle; φ also increases with the increase in the gas-liquid velocity ratio. This study adopts a dynamic slug flow model to simulate the well completion and the throttle cases under field conditions based on the hydraulic similarity principle. The pressure and liquid holdup results show that the large-scale segregated completion will lead to decreasing flow instability and the decrease in throttle opening will also lead to the decrease in flow instability.
这项工作聚焦于弯管中的两相段塞流，这在油气井中非常常见。就油气生产而言，不稳定的段塞流可能会引发若干问题并降低产量。在当前工作中，针对不同的流入角度和气液速度比，在几根弯管中进行了段塞流实验。使用罗斯蒙特压力计在弯管处测量实时压力，并使用电导率传感器测量持液率，这些用于计算段塞长度。然后，我们定义无量纲段塞长度φ = / （段塞长度 与管道直径 的比值），这能使段塞分析不受不同管道直径的影响；φ还用于分析段塞流状态的变化。实验结果表明，无量纲段塞长度φ随管道曲率的增加而增大；φ随流入角度的增加先减小后增大；φ也随气液速度比的增加而增大。本研究采用动态段塞流模型，基于水力相似原理模拟现场条件下的完井和节流情况。压力和持液率结果表明，大规模分离完井会导致流动不稳定性降低，节流开度的减小也会导致流动不稳定性降低。
