Prediction Model of Wellbore Temperature Field during Deepwater Cementing Circulation Stage

Accurate prediction of the wellbore temperature field during the cementing circulation stage contributes to the design of cement slurry performance parameters and the calculation of wellbore pressure. Therefore, based on the wellbore flow mechanism and heat transfer theory, the influence of different regional differences on the heat transfer process was considered, and the discrepancy of different fluid thermodynamic parameters and their characteristics of variation with well depth were analyzed. Combined with the fluid interface position description equation, a set of wellbore temperature field prediction models suitable for the deepwater cementing circulation stage was established. The model was verified by the measured data from two wells, and the key influencing factors were analyzed. The results show that the drilling fluid should be circulated for 2~4 cycles prior to cement slurry injection, so as to reduce the impact of circulation time changes on the bottom hole circulating temperature (BHCT) during the injection. During the cement slurry injection process, larger flow rate causes less obvious warming or cooling of the surrounding environment. If the influence of temperature on specific heat capacity is not considered in the calculation process, it is predicted that the BHCT will be 2~4 °C higher. The influence of cement slurry density on temperature is related to the direction of heat transfer. The research results can be used to guide deepwater cementing.