A semi-analytical model for predicting inflow profile of horizontal wells in bottom-water gas reservoir

Abstract

In this study, a semi-analytical model which couples the reservoir and wellbore, is developed to predict the inflow profile of horizontal wells in a box-shaped gas reservoir with a bottom water zone. The developed gas reservoir flow model is based on a 3D volumetric source model which considers the reservoir properties in the region near the wellbore, in terms of anisotropy, heterogeneity and formation damage. Meanwhile, pressure drops in the wellbore flow model was also considered, due to fluid flow in the horizontal wellbore. The model was calculated by a field case, and the results of the calculation were compared with a commercial simulator: ECLIPSE (Schlumberger, 2011). The comparison between the developed model and ECLIPSE indicates that, a good match was obtained, so that, the model derived in this study can be applied to predict the inflow profile of horizontal well in a gas reservoir with bottom water zone. Moreover, sensitivity analysis is conducted by using various wellbore pressure drops, wall roughness, skin factors, wellbore diameters, anisotropy and producing pressure drops.