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.

• 由于携砂液向地层的滤失以及通过筛管缝隙的流体质量交换,水平井砾石充填过程中冲筛、井筒环空两个流动系统均为复杂的变质量流。