Traditional decline curve analysis is an empirical procedure used mainly to predict recoverable reserves and future production rates, based on the boundary dominated declining rate. Modern (typecurve) analysis, however, are partially (Fetkovich) or fully derived analytically, based on reservoir fluid flow equations and assuming some simplifying conditions. Such typecurves are generally used for predicting reserves and future production rates as well as reservoir parameters.

In the current study, two cases have been analyzed using traditional and modern decline curves in an attempt to estimate key reservoir parameters. In the first case, an implicit reservoir simulator has been used for generating a set of declining rates for a well operating at ideal conditions, i.e. a homogenous cylindrical reservoir with isotropic permeability producing single phase oil at a constant bottomhole pressure. The generated data ware then used as an input for a decline curve analysis software to investigate the reliability and accuracy of estimated permeability, skin, and drainage area. In the second case, the declining rate of a real oil well is analyzed in terms of the previously cited parameters by the same software. The results of both cases indicate a good agreement between the actual and estimated parameters, with the Blasingame typecurve as the most accurate decline curve analysis technique.

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