In this paper, we present a model for calculating the open-hole extended-reach limit for an extendedreach well which takes into account such factors as annular pressure loss, equivalent density of formation fracture pressure, etc. Studies have shown that the proposed model is the most accurate model available. We also present results of an analysis of the effect of different drilling parameters on the extended-reach limit of the well. Calculations have shown that the extended-reach limit is proportional to the equivalent density of the formation fracture pressure and inversely proportional to the pump rate, the drilling fluid density, and the mechanical rate of penetration (ROP).