Modern downhole temperature measurements indicate that bottomhole fluid temperature could be significantly higher or lower than the original reservoir temperature, especially in reservoirs where high pressure drawdown is expected during production. This recent finding contradicts the isothermal assumption originally made for routine caluculations. In a high-pressure drawdown environment, the Joule-Thomson (J-T) phenomenon plays an important role in fluid temperature alteration in the reservoir.
This paper presents a robust analytical model to estimate the flowing-fluid temperature distribution in a reservoir that accounts for the J-T heating or cooling effect. All significant heat-transfer mechanisms for fluid flow in the reservoir, including heat transfer due to convection, J-T phenomenon, and heat transfer from over- and under-burden formations, are incorporated in this study. The proposed model is successfully validated with results from a rigorous numerical simulator using field data.