Coupled modeling circulating temperature and pressure of gas–liquid two phase flow in deep water wells

Accurate predictions of wellbore temperature and pressure profile are essential for underbalanced drilling operations while circulating aerated drilling fluids in deep water wells. Based on aerated drilling fluids flow and heat transfer characteristics in deep water wells, coupled conservations of mass and momentum and energy have been developed to compute wellbore temperature and pressure profile. Discrete equations were formulated via thermodynamics correlations and finite volume integration. An algorithm was developed in which temperature and pressure are coupled, flow fields inside drill string and annular are coupled. Effects of energy sources, riser insulation blanket, sea current, etc. on heat transfer of gas liquid two phase flow with environment were considered in the model. Comparisons with Keller's wellbore temperature data and two phase flow pressure data from the Louisiana full scale experiments confirmed this model and the suggested algorithm. Wellbore temperature and pressure distribution while circulating aerated drilling fluids were analyzed with a simulated deep water well.

► Coupled mass and momentum as well as energy conservation equations are established. ► The outlet temperature is about 14 °C in a deep-water well. ► The bottom hole temperature decreases gradually with increased circulating duration. ► Deep-water wellbore pressure distribution is almost independent of circulating periods.