A fully-coupled thermal multiphase wellbore flow model for use in reservoir simulation

A numerical thermal multiphase wellbore flow model is developed and applied. The formulation entails one-dimensional spatial (axial) and temporal discretizations and includes coupled mass conservation equations for oil, water and gas components, three-phase fluid flow, an energy conservation equation, and a pressure drop relationship. A drift-flux model is employed to represent slip between fluid phases. The model is implemented into a reservoir simulator to enable fully coupled reservoir-wellbore simulations. A series of numerical results are presented, including validation against previous experimental results, verification against an analytical model, and simulations of complex thermal multiphase flow scenarios that involve vertical and multilateral wells coupled with oil reservoir models. Taken in total, these numerical simulation results demonstrate the broad applicability and robustness of the new wellbore flow model.