The study of proppant transport in fractures is of great significance for guiding fracturing design and evaluation. The current researches of proppant placement rules mainly focus on displacement

proppant type

fracturing fluid viscosity

etc. However

there are few studies on the effects of different proppant combinations on proppant transport rules. In this paper

the experimental schemes of the influence of different proppant combinations on proppant transport rules are designed. Then the self-designed visual parallel plate device is used to carry out these experiments. The results show that the distribution of the proppant with smaller particle size is more evenly in the fractures

but the proppant with larger particle size is easier to settle at the wellhead. When medium particle size and large particle size proppant are combined in different proportions

there are small differences in the equilibrium heights of the formed sand bank

but the differences between the non-uniformity of the sand bank height are large. Meanwhile

a large amount of proppant settles at the entrance end of the crack. The proppant filling amount in the deep crack is small

and the effective filling crack with sufficient length and diversion capacity is failure to be formed. When the medium and small particle sizes are combined in different proportions

the proppant can obtain a farther distance than that of the combination of medium particle size and large particle size. The height of the formed sandbank is ideal

and the difference in the non-uniformity of the height of the sand bank between different proportions is also greater.