垂直井砾石充填防砂最小排量的确定方法

将水平管中清水及低粘液体携砂时的临界流速公式用于计算垂直井砾石充填防砂的最小排量 ,研究了垂直井低粘液体及清水携砂液临界流速计算公式的特点及应用条件 ,分析了射孔孔眼临界流速及防砂井最小排量的影响因素 ,并利用现场数据计算了防砂井最小排量。结果表明 ,射孔孔眼直径及携砂比增加时 ,临界流速增加 ;射孔密度、射开厚度、孔眼直径及临界流速增加时 ,砾石充填最小排量也增加。提出的临界流速计算方法可用于现场施工排量的设计 ,携砂液初始排量接近或高于临界排量是保证防砂成功并获得较长有效期的根本条件。

Determination method for minimum flow rate of gravel pack in vertical well

The formulas for calculating critical flow velocity of sand-laden fluids such as water and viscous fluid in horizontal pipe were applied to calculate the minimum rate of gravel pack in vertical well. The characteristics and the application conditions of these formulas were analyzed. The factors that influence the critical injection velocity in perforations and the minimum injection rate of gravel pack were discussed. The minimum flow rate of gravel pack well was calculated with the critical velocity formulas. The result shows that the critical flow velocity of sand-laden fluid in perforations increases with the increment of diameter of perforation tunnel and the concentration of gravel in slurry. The minimum injection rate of gravel pack increases while increasing the diameter of perforation tune, the perforation density, the perforated thickness and the critical velocity. The result also shows that these formulas can be used to determine the flow rate of gravel pack. The flow injection rate of sand-laden fluid greater than or close to the minimum flow rate is very important to ensure the sand control success and prolong the effective life.