Hydraulic heads from a calibrated, three-dimensional, constant-density, ground-water-flow model were used to compute Hubbert oil potentials and infer secondary petroleum migration directions within the Llanos Basin, Colombia. The oil potentials for the C7 reservoir show evidence of the development of two hydrodynamic stagnation zones. Hydrodynamic effects on secondary oil migration are greatest in the eastern Llanos Basin, where structural slopes are lowest and local hydraulic-head gradients drive ground-water flow westward down
