A Fully Implicit Thermal Wellbore Model for Multicomponent Fluid Flows

Abstract

Summary This paper describes a thermal wellbore model that simulates flow hydraulics in the wellbore and heat transfer between the wellbore fluid and the overburden. The thermal wellbore model includes the transient differential equations for multicomponent three-phase fluid flow in the wellbore and the transient heat conduction equation in the overburden. Phase behavior of the wellbore fluids is obtained from isenthalpic flash calculations, which compute the phase splits and compositions at a specified pressure and enthalpy. The wellbore and overburden equations in the entire discretization domain are solved simultaneously with a fully implicit Newton's method. The thermal wellbore model was validated with steam-injection and gas-condensate production field data. The calculated heat losses and pressure drops compared favorably with published models. The thermal wellbore model is also used to predict the critical production rate of methane above which hydrate will not form.