In this study, a 1D unsteady-state two-phase mechanistic model of cuttings transport with foam in vertical wells has been developed. The model is solved numerically to predict the optimum foam flow rate and theological properties to maximize, the cuttings transport efficiency in vertical wells. Comparisons of model predictions with the field test data have shown that model predictions are in close agreement with the field test results. The numerical solution allows analyzing the effects of borehole geometry, drilling rate, foam theological properties, gas and liquid flowing rates, and reservoir fluid influx on the cuttings transport efficiency when drilling vertical wells. Results of sensitivity analysis study are presented.