关键词: 泡沫流体, 携砂, 冲砂, 洗井, 水平井, 数值模拟

Abstract:

The numerical simulation has been carried out in the study on the sand carrying capability of foam fluid in horizontal
well sand washing operations with the computational fluid dynamics（CFD）software. The results indicate that by simulation，
we obtained the maximum volume fraction to of foam fluid and the minimum volume fraction to of sand particles are obtained
in the center of annulus in when keeping the tube in the middle. Because of the carrying effect of foam fluid，the speed of
sand particles in center area change with migration journey，and the average speed of sand particles increase slightly than inlet
velocity. Erosion area increased with the sand size，and the increase of sand size also has large impact on the sand carrying
capability of foam fluid. But overall，the erosion rate of sand to pipe wall is small. When the flow rate of foam is 0.30 m/s and
the sand diameters range from 0.1 to 2.0 mm，sand particles can be suspended in the foam fluid and move with it，and there is
no settlement phenomenon. When the flow rate of foam is 0.90 m/s or 1.50 m/s，the sand particles，ranging from 0.1 to 2.0 mm
in diameter，can smoothly pass the annular flow channel in horizontal section. The bigger the sand diameter is，the lower sand
carrying efficiency of foam.

Key words: foam fluid, sand carrying, sand washing, well flushing, horizontal well, numerical simulation