Distribution of Hydraulic Head in the Winterburn Hydrostratigraphic Unit

This map depicts the distribution of groundwater hydraulic head in the Winterburn hydrostratigraphic unit (HSU). The horizontal and vertical extent of the unit was adopted from version two of the 3D Provincial Geological Framework model of Alberta. The map is a result of an empirical Bayesian kriging technique using publicly available 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 HSU rather than site-specific values. The final gridded map surface was clipped based on the spatial distribution of representative pressure data. 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. Three additional inset maps show the results of the cumulative interference index analysis, the distribution of total dissolved solids (TDS) and the results of water driving force analysis, respectively. The geometry and variable thickness of the Winterburn HSU are illustrated on schematic cross-sections, and the relationship between geological units is further described in an accompanying regional lithostratigraphic and hydrostratigraphic table.