ERTh: Electrical resistivity monitoring of heat tracer to characterize aquifer heterogeneities

Knowledge of spatially continuous hydraulic conductivity (K) distributions is crucial to the accurate modeling of hydrogeological processes. The representative scales of K estimates from traditional slug and pumping tests are, however, inadequate to accurately predict groundwater flow and contaminant transport processes. While several studies have utilized electrical resistivity tomography (ERT) to quantify high-resolution K fields, they typically involve the injection of large volume of saline tracer into an aquifer, which is feasible but impractical. We present a new technique, electrical resistivity thermography (ERTh), which uses heat instead of saline tracer. ERTh is based on the hypothesis that spatially continuous K variations can be estimated via ER monitoring of a heat tracer experiment. Unlike saline tracers, heat tracer experiments are easier to manage and repeatable with minimal environmental impact. The strategy couples ER with heat flow and transport processes through a petrophysical relationship to estimate spatially continuous, high-resolution K distributions. The technique is illustrated with a 2D synthetic heat tracer with ER monitoring experiments. The target consists of three lenses of high-K gravel and medium-K coarse sand embedded in a comparatively low-K fine sand background. The experiment involved continuous injection and extraction of heat at the left and right boundaries, respectively. We performed ER monitoring of the heat transport and temperature measurements at four multi-levels near the heat extraction well. The desired K-field was estimated from the joint time-lapse ER and temperature measurements using coupled stochastic inversion. The results demonstrate the potential of ERTh to estimate high-resolution, spatially continuous K configurations.

Grantor dc:publisher

State University of New York at Buffalo

Year dc:date.issued

2018

Author dc:creator

• Adetokunbo, Rasheed Peter

Contributors dc:contributor

• Oware, Erasmus
• Geology

• geophysics
• hydrologic sciences
• environmental geology

Statement dc:rights

• Users of works found in University at Buffalo Institutional Repository (UBIR) are responsible for identifying and contacting the copyright owner for permission to reuse. University at Buffalo Libraries do not manage rights for copyright-protected works and cannot assist with permissions.
• Copyright retained by author.

Language dc:language

eng

Handle dc:identifier

http://hdl.handle.net/10477/78100

OAI record oai:identifier

https://ubir.buffalo.edu/oai/request?verb=GetRecord&metadataPrefix=qdc&identifier=oai%3Aubir.buffalo.edu%3A10477%2F78100