Field performance of the heat pulse flow meter: Experiences and recommendations

• Practice orientated article on field methods to measure flow in fractures
• Overview of the working principle of the heat pulse flow method and analysis are given.
• Report on flow measurements in fractured coal aquifers on two characteristically different sites in Eastern Australia.
• Based on the field experience the condition dependent performance is reported.
• Limitations and benefits of the measurements are highlighted.

A large extent of groundwater flow in fractured aquifers follows fractures and cleats. The heat pulse flow meter allows the localisation and quantification of in- and outflow along borehole profiles through field measurements and subsequent inverse modelling. In this paper the method is presented and its feasibility is discussed based on the experiences gained from two different field sites. Field work was undertaken on two sites on the East Coast of Australia under different conditions leading to different outcomes. The experiences with the heat pulse flow meter method and concluding recommendations are reported to help improve the performance of the method.