An efficient semi-analytical solution method appropriate for the approximate modeling of the performance of non-conventional wells operating under primary production is described. The approach, referred to as the s-k* method, accounts approximately for the effects of reservoir heterogeneity and for pressure losses within the wellbore. The accuracy of the method is demonstrated through comparison to detailed finite difference results. Extensive calculations for the performance of non-conventional wells in multiple realizations of log-normally distributed permeability fields are then presented. The effect of wellbore hydraulics on well performance is assessed for several different well geometries and for varying degrees of reservoir heterogeneity. Comparisons between ensemble-averaged quantities (i.e., results averaged over many realizations) and results for a single "average" (homogeneous) reservoir representation are also made. As expected, these calculations differ in general, though for some quantities (e.g., productivity ratio) the homogeneous results give very accurate estimates. The overall approach provides an efficient means for estimating the combined effects of reservoir heterogeneity and wellbore pressure losses on the productivity of non-conventional wells.

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