流速和环空偏心对泡沫携砂能力的影响数值模拟

Numerical simulation for impact of velocity and annular space eccentricity on prop-carrying capability of foam fluid

泡沫流体广泛应用于油井的冲砂洗井作业中,携砂能力是衡量其性能的一项重要指标。利用FLUENT软件中的分散相模型对泡沫流体的携砂能力进行了数值模拟,得到不同直径的砂粒在同心环空和偏心环空中的携砂率,研究了泡沫流速和环空偏心对泡沫携砂能力的影响,并得出水平井泡沫流体冲砂洗井的安全携砂条件。从计算结果可看出,不同直径的砂粒在泡沫流体中的携砂率随环空倾角有不同的变化关系,携砂率随泡沫流速的增大而提高,环空偏心使得泡沫流体的携砂率降低,而且对接近水平段的影响尤为突出,对接近竖直段的影响较小。

Foam fluid is widely used in sand-flushing operations in oilfields, while the prop-carrying capability of foam fluid is very important. Numerical simulation for prop-carrying capability of foam fluid is conducted using the discrete phase model of FLUENT. The sand carrying rate of sands with different diameters in concentric and eccentric annular spaces is obtained, impact of velocity and annular space eccentricity on prop-carrying capability of foam fluid is researched, and safe sand carrying conditions in sand-flushing operations for horizontal oil wells are obtained. The results show that sand carrying rate of sands with different diameters has different relations with the inclination angle of annular pipes. Sand carrying rate increases with the increase of foam fluid velocity, while it decreases because of annular space eccentricity. The impact of annular space eccentricity on the horizontal segment is less than that on the vertical segment of oil wells.