Abstract Physical model experiments have been performed on perforation cavities in a weak sandstone. The objective of the study has been to investigate the effect of the flow geometry on sand production risk. Two extreme geometries have been tested, one with flow mainly axially towards the tip of the cavity and one with fluid flowing radially towards the side of the cavity. The experiments have been performed in a special pressure vessel for sand production studies. We have recorded the deformation of the cavity, the flow rate through the sample and monitored sand production and acoustic emission activity as functions of the imposed confining pressure and pore pressure drop across the sample. From the tests, we have found initial cavity failure and initial sand production at various combination of confining and pore pressure. The results have also been corroborated by finite element simulations. We have concluded that by directing the flow through the bottom of the cavity sand production is inhibited compared to the case where flow mainly enters through the side of the cavity. This is because the cavity fails along the wall first, while the bottom is intact. As flow promotes the removal of failed material, radial flow increases the risk of sand production.