Coupled calculation of transient temperature, pressure and cuttings transport and its applications in drilling

Abstract Hydraulics monitoring is an important component of intelligent drilling. Although wellbore temperature, pressure, and cuttings transport have been investigated separately, few models incorporate all these factors and are used for real-time monitoring. Based on previous studies, this work develops a coupling method with flexible solution schemes for wellbore temperature-pressure fields and transient cuttings transport. The method supports standalone simulations for simple drilling and coupled calculations for complex cases. A dynamically updated correction strategy is proposed to reduce errors in pressure prediction, alongside a multi-curve equivalent circulating density (ECD) monitoring method to overcome the limitations of the conventional single-curve ECD approach. Integrating these components forms a real-time drilling hydraulics monitoring framework. Two case studies are presented to illustrate the application of the framework in monitoring and analyzing drilling hydraulic conditions. The results reveal that transient wellbore temperature and pressure, as well as cuttings transport, significantly affect wellbore flow, especially in complex wells. Multiple ECD curves assists engineers in better assessing hydraulic conditions, notably when ECD derived from standpipe pressure (SPP) is adopted instead of theoretically calculated ECD in the absence of measured bottomhole pressure. This work improves real-time drilling Hydraulics monitoring and provides practical guidance for field operations.