Wellbore storage effect can highly degrade conventional pressure buildup and drawdown tests data disturbing the formation characterization of the wellbore surrounding area. Constant bottomhole pressure tests will eliminate this pitfall and provide good reservoir describtion.

This paper applies direct synthesis technique for infinite conductivity fractured wells producing at constant bottomhole pressure from finite reservoirs. Without resolving to type-curve matching or regression procedures, this technique analyzes the log-log plot of the reciprocal rate and reciporocal rate derivative data to determine the fracture and reservovir parameters. These plots reveal the presence of straight lines corresponding to linear and pseuso-radial flow regimes; while the the boundary flow effect is detected by an exponential behavior. A 0.65 slope straight line describing the transition period between the pseudo-radial and the boundary effect flow regimes in rectangular systems is also presented. The distinct features of the straight lines' slopes and intersection points are used to calculate various reservoir and fracture parameters such as fracture half-length, reservoir permeability, skin factor, drainage area and shape factor. Equations corresponding to the points of intersections are very useful to verify the accuracy of the results obtained from the slopes of the different flow regimes.

A systematic step-by-step procedure illustrating the methodology of the proposed technique for the analysis of linear, pseudo-radial, pseudosteady state flow regimes is described. Detailed examples using different simulated cases are presented to show the applicability of the proposed method.

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