Geophysical Characterization of an Undrained Oil Sands Tailings Pond Dyke Alberta, Canada

Abstract

Geophysical characterization of an undrained oil sands tailings pond dyke was conducted at Syncrude Canada’s Southwest Sand Storage Facility (SWSS). Push tool conductivity (PTC), electromagnetic (EM), and electrical resistivity tomography (ERT) methods in conjunction with hydrogeological and chemistry measurements were used to investigate soil moisture, hydraulic head, and groundwater salinity distributions. Normalization and calibration procedures were conducted on EM data to build statistically consistent maps between survey years. An Archie’s Law petrophysical model was utilized to relate measured bulk conductivity, from geophysical surveying, with measures of soil moisture and fluid electrical conductivity. It was found that a relatively strong relationship between bulk electrical conductivity and soil moisture exists, while weak to no correlation was observed between bulk and fluid electrical conductivity. ERT surveying was capable of clearly identifying the location of the water table within the dyke. This study provides a unique look into the application of geophysical techniques to investigate soil moisture, hydraulic head, and salt distribution in an active undrained tailings dam structure.