Prediction and Analysis of Wellbore Temperature and Pressure of HTHP Gas Wells Considering Multifactor Coupling

Abstract

In the production process of high-temperature and high-pressure gas wells, it is very important to understand the changes of the temperature and pressure parameters in the wellbore with the depth of the well. Based on the conservation of fluid energy, momentum, and mass in the wellbore, considering the influence of high-temperature and high-pressure gas wells on the temperature and pressure of the wellbore under the coupling of fluid velocity, density, and Joule–Thomson effect, a wellbore temperature and pressure prediction model was established based on this. Then, we could obtain wellbore temperature and pressure distribution along the well depth. The comparison with the actual wellbore data of Tarim X gas well and XX well in Southwest China shows that the calculation result of the multifactor coupling model is less than 3% of the field measured data, which verifies the accuracy of the multifactor coupling model result. Based on this, the effects of different gas production and production time on the temperature and pressure of high-temperature and high-pressure gas well boreholes were analyzed. The results show that for the Tarim X gas well, when the gas production is 80 × 104, 90 × 104 and 100 × 104 m3/day, the corresponding wellhead temperatures are 56.1, 65.3, and 69.8 °C; the corresponding wellhead pressures are 62.4, 62.2, and 62.0 MPa. When the production time is 1 day, 10 days, and 20 days, the corresponding wellhead temperatures are 61.5, 63.6, and 64.8 °C, respectively; the corresponding wellhead pressures are 63, 62.8, and 62.4 MPa.