The Influence of Rock Heterogeneity on Water Coning Below Horizontal Wells

When producing oil from an underground reservoir, a water cone will form below the production well leading to early breakthrough. In particular for the production of thin oil nms, a good understanding and estimate of the sensitivity for water coning is required. In heterogeneous reservoirs where horizontal wells are applied, not much knowledge is present to relate heterogeneity to production behaviour. In this paper we investigate the effects of dimensionless numbers arid of reservoir heterogeneity on the breakthrough time of a horizontai production well. We develop a model for the simulation of water coning in heterogeneous oil reservoirs. We consider flow of two immiscible and incompressible fluids in a porous medium. The model consists of a coupled system of a stream function and a saturation equation. The saturation equation is solved using a finite volume method with the aid of the Godunov flux. First we validate the numerical simulator by testing convergence under grid refinement. Then the influence of the dimensionless numbers and various geological settings on the breakthrough time is considered. From the results we conclude that knowledge of the influence of reservoir heterogeneity on water coning is needed in determining optimal production strategies and to minimize the occurrences of early water breakthrough.