Distribution of Hydraulic Head in the Exshaw–Banff Hydrostratigraphic Unit

This map depicts the distribution of hydraulic head in groundwater in the Exshaw–Banff hydrostratigraphic unit (HSU). The map is a result of an empirical Bayesian kriging technique using publicly available data pressure data from oil and gas well drillstem tests.

The distribution of hydraulic head was mapped at a regional scale using many years of data, thus providing a good indication of hydraulic head within the unit rather than site-specific values. The uncertainty of prediction is depicted on an inset map, which shows the residual values (predicted value minus measured value) plotted at each location to indicate where underprediction or overprediction occurs. A Cumulative Interference Index (CII) methodology was used to identify and remove production/injection influenced drillstem tests from the underlying dataset. Two additional maps show the distribution of total dissolved solids and the results of water driving force analysis, respectively. The geometry and variable thickness of the Exshaw–Banff HSU is shown on schematic cross-sections.