Influence of Pressure Drop Along the Wellbore on Horizontal-Well Productivity

This study investigates the effect of wellbore pressure drop on horizontal-well productivity and presents guidelines to design horizontal-well completions. The central new result of this study is a general semianalytical model that couples wellbore and reservoir hydraulics. The model enables the rigorous evaluation of horizontal-well productivity and can be used to determine optimum well length, wellbore diameter, and production rate. Field examples are presented to emphasize the consequences of the infinite-conductivity well assumption. The extension of the model to the flow of real gases is also discussed. It is shown that the pressure losses due to acceleration may play an important role in the wellbore hydraulics of horizontal gas wells and should not be ignored.