Development and Application of a Fully-Coupled Thermal Compositional Wellbore Flow Model

Abstract

Abstract Thermal recovery processes are widely used for heavy oil production and are under investigation for other unconventional resources. The management and optimization of these processes require accurate representations of relevant physical phenomena in simulation models. An important aspect of the simulation capability is the modeling of flow in the wellbore and the coupling of wellbore and reservoir flows. In previous work, we developed and applied a black-oil thermal multiphase wellbore model and linked it to Stanford's General Purpose Research Simulator (GPRS). In this paper, we extend this formulation to treat thermal compositional systems. GPRS already contains a thermal compositional capability for reservoir flow; here we develop and test a thermal compositional wellbore model. This wellbore model includes an energy conservation equation, mass conservation equations for each component, and a general pressure drop relationship. The multiphase wellbore flow is represented using a drift-flux model, which includes slip between the three phases. The model determines the temperature, pressure, mixture flow velocity and component fractions as functions of time and axial position along the well. We apply the coupled thermal compositional wellbore-reservoir model to the simulation of several cases involving thermal effects. These include a verification example, in which we compare results from the compositional formulation to those of a black-oil model, and an example with seven components. Different well geometries (e.g., dual-lateral and deviated with varying inclination angle) are considered in these applications.