**5. Conclusions**

The proposed transient heat transfer model allows us to obtain the temperature of both wellbore and formation throughout the whole well depth. A quantified concept, TDR, is introduced for quantitatively analyzing thermal disturbance in the formation. The TDR, a newly introduced concept, can be an index indicating how uncertainty can exist in the temperature measurement in any well test after a drilling operation. The following are the delivered significant insights into understanding thermal disturbance:


**Author Contributions:** Conceptualization, M.J.; methodology, M.J. and J.A.; formal analysis, M.J., T.S.C., and J.A.; investigation, M.J. and J.A.; writing—original draft preparation, M.J. and J.A.; writing—review and editing, T.S.C. and J.A.; supervision, J.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.

**Conflicts of Interest:** The authors declare no conflict of interest.
