Measurement of the Spatial Distribution of Heat Exchange Using Fiber Optic-Distributed Temperature Sensing

Tuesday, September 24, 2013: 12:50 p.m.
Adam Hawkins , Department of Geological Sciences, California State University Long Beach, Long Beach, CA
Matthew W. Becker, Ph.D. , Geological Sciences, California State University Long Beach, Long Beach, CA

Highly channelized flow in fractured geologic systems has been credited with early thermal breakthrough and poor performance of geothermal circulation systems.  An experiment is presented here in which the effect of channelized flow on fluid/rock heat diffusion is measured.  Hot water was circulated between two wells in a single bedding plane fracture and the elevation of rock matrix temperature was measured using fiber optic Distributed Temperature Sensing (DTS).  Between wells with good hydraulic connection, heat transfer followed a classic dipole sweep pattern.  Between wells with poor hydraulic connection, heat transfer was skewed toward apparent regions of higher transmissivity (or larger aperture).  These results are consistent with hydraulic and tracer tests, as well as ground penetrating radar imaging, that shows a heterogeneous distribution of transmissivity. The results suggest that flow channeling can have a significant impact on heat transfer efficiency even in single planar fractures.

Adam Hawkins, Department of Geological Sciences, California State University Long Beach, Long Beach, CA
TBA


Matthew W. Becker, Ph.D., Geological Sciences, California State University Long Beach, Long Beach, CA
Matt Becker holds a B.S. in Geology from Michigan State, and an M.S. and Ph.D. in Civil Engineering from the University of Texas. He was an NRC Post Doctoral Associate with the USGS National Research Program and a Senior NRC Associate with NASA Goddard Space Center. In 2007 he was a Fulbright Lecturer with the University of Trento, Italy. He is currently a Professor of Geology and holds the Conrey Chair in Hydrogeology at California State Long Beach. His current research interests include flow and contaminant transport in fractured bedrock, groundwater/surface water interactions, and the remote sensing of groundwater.