A temperature-pressure coupling model for predicting gas temperature profile in gas drilling

In the gas drilling design, accurate prediction of wellbore temperature profile is very crucial. Different from liquid fluid, physical and thermophysical parameters gases are sensitive to change pressure temperature, at same time, these will react against pressure. Based on energy conservation principle, a temperature-pressure coupling calculation model was established predict during process. The solved by cycle iteration method. shows that annular rises sharply near wellhead, drops bottom hole little higher than formation in other places. Without considering influence friction heat, calculated lower actual temperature. Temperature trends under different pump rates larger rate leads range wellhead hole. Compared with rate, bit nozzle size has more drop range. reduction increases 31.3-57.2? while decreases 539-339 mm2.