LAUSR

Abstract In most super-heavy oil reservoirs, depletion recovery is one of the important cold recovery methods accompanied by foamy oil production. However, the inflow profiles of horizontal wells in super-heavy foamy oil reservoirs cannot be obtained by conventional methods at present. In this study, a semi-analytical model which couples the wellbore and reservoir was established to predict the inflow profile of horizontal wells in super-heavy foamy oil reservoirs with cold production method. The coupled wellbore/reservoir model is based on the prediction of the dynamic physical property parameters of foamy oil, and employs reservoir engineering methods, such as the microelement, mirror reflection, and potential function methods. The numerical solution was obtained by applying iteration method in MATLAB. Meanwhile, the model accounts for formation heterogeneity along the horizontal well that has never been considered before and pressure drop loss along the horizontal wellbore. The model was applied to a field case, and the calculation results were compared with those predicted by using the Joshi and Furui productivity formulas. It showed that the developed model led to the smallest errors from field production data, which further verifies the accuracy of the model. Moreover, sensitivity analysis is conducted by changing the permeability distribution along the horizontal well and the length of the horizontal section based on the established model. And the results are instructive for horizontal well optimization design. In short, this model is of great significance for productivity calculations, horizontal well design optimization, and production predictions of cold production with horizontal wells in super-heavy oil reservoirs.