A Reservoir/Wellbore-Coupling Model for the Pressure, Flow Rate, and Optimum Perforation Distribution in Gas Wells

Due to the variation in pressure drawdown along a well, pressure drop can occur in a vertical well. Accurate prediction of the inflow performance for perforated vertical wells is of great significance to reservoir analysis and perforation optimization. Under steady-state inflow, a reservoir/well-bore-coupling model is proposed that combines a numerical reservoir model and a semianalytical wellbore model. One type of optimization problem is also established that considers the effects of perforation density on the productivity of a vertical well, for which the vertical-well production is treated as an objective function. A number of experiments are presented demonstrating how the model could be used to obtain the optimum perforation distribution for infinite-conductivity and finite-conductivity wells.