Distributed temperature fibre optic sensing (DTS) is now commonly used as part of the groundwater characterization toolkit. In this paper we present examples from two recent field site operations where DTS provided invaluable information about well operations. In a CO2 controlled release experiment in Western Australia, we discuss the surveillance of work-over operations using distributed temperature sensing in both the monitoring and injection wells. A wide range of well operations were performed in these two wells including completion installation and cementing. DTS was the sole tool used to monitor the drilling of an unexpected cement infill inside the monitoring well. In a different project in Victoria, where two deviated water wells were drilled through a fault zone, permanently installed fibre optics cable were used to inform the grouting process and the fault location. In both these case studies, DTS proved to be a valuable and reliable tool throughout the entire lifecycle of the well operations.