Scaleup in the near-well region

Scaleup techniques are commonly used to coarsen detailed geological models to scales more appropriate for reservoir simulation. These techniques typic ally generate upscaled permeabilities through solution of the local pressur e equation, subject to some type of linear boundary condition. In the near- well region, coarse scale permeabilities computed in this manner may not ad equately capture key features of the fine scale how. In this article, we pr esent a general method for computing accurate coarse scale wellblock transm issibilities and well indexes for vertical wells in two and three dimension s. The method is based on the solution of local well-driven flow problems s ubject to generic boundary conditions. Simulation results for two-dimension al systems indicate that the near-well treatment always provides improved p redictions compared to those obtained using standard methods. In some param eter ranges, this improvement is quite substantial. Several three-dimension al models with vertical wells are also considered and improvement relative to the standard approach is achieved in all cases. Extension of the method to accommodate more general well configurations could result in significant ly improved coarse scale simulations of nonconventional wells.