Based on the digital mask technique, the distribution of sand area density and the sediment-transport rate in flow field were obtained.
采用图像处理的数字掩码技术，处理图像得到了沙粒在流场中的面密度以及单宽输沙率。
2
It is wrong that some users want to reduce the operation cost through reducing the flowrate of sand.
有些用户想要通过降低砂料流速降低运行成本，这是错误的。
3
The critical flow velocity of reservoir, sand production rate of oil well and sand control rate of sand retention layer are the key of the technology that is successfully used.