Thermal Hydraulics of Wellbores and Surface Lines During Steam/Hot Water Injection—Part I: Theoretical Model

A mathematical model is proposed for analyzing the thermal hydraulic behavior of wellbores and surface lines. The model discusses two-phase pressure drop and heat transfer for a variety of practical wellbore boundary conditions and includes theoretical formulations for calculating effects of geothermal gradient, transient heat flow to the surroundings of the wellbore, and radiation and convection heat transfer in the annulus. The model has been applied to evaluate the effects of insulation thickness, injection rate and injection time on steam temperature and quality. Some interesting performance behaviors are noted. The predictions of the model are compared with the results of other models [1, 2] and a field case [29].