• Centrifugal hypergravity experiments successfully reproduce stress and fluid pressure gradients, revealing that higher g-levels cause increasingly asymmetric hydraulic fracture propagation.
• A theoretical fracture mechanics model shows that when the fluid pressure gradient exceeds the stress gradient, a positive net gradient increases net pressure at the lower fracture tip, promoting downward growth.
• The study provides the first experimental verification that the net gradient (difference between fluid pressure and stress gradients) significantly alters hydraulic fracture propagation.
• Findings offer practical guidance for optimizing wellbore placement in reservoirs with stress gradients to enhance fracture height growth and stimulated reservoir volume.