Efficient management of oil reserves involves an understanding of the mechanisms that control the bypassing of oil in water drive reservoirs. The existing analytical models of water front advancement in side-water reservoirs do not account for the combined effects of water underruning and coning. This paper gives correlations for the prediction of the amount of bypassed oil in side-water systems. The correlations have been developed using numerical simulation and an experimental design framework. Considered in the correlations are the effects of dip angle; vertical-to-horizontal permeability ratio, oil viscosity, production rate, oil density, and well penetration.