During the process of gravel-packing in horizontal Wells, there are the filtration flow of the carrier fluid to the formation and the exchange flow through the screen slots.

This method determines the external dimension of packing-box according to package standards and the side of vehicle car. The new packing-box can improve the transport ability of carrier.

The invention has simple process, uniform grain diameter, narrow graininess distribution, high carrier and packing rate on hydrophobic drug.