Distribution of Hydraulic Head in the Cardium Hydrostratigraphic Unit

This map depicts the distribution of hydraulic head in the Cardium hydrostratigraphic unit (HSU). The map is a result of an empirical Bayesian kriging technique using representative hydraulic head values calculated from pressure data from oil and gas well drillstem test pressures and static water level data from water wells.

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. Hydrogeological mapping was limited to the northern portion of the Cardium HSU, where hydrocarbon production is infrequent and isolated. More extensive production from hydrocarbon pools is found throughout the remainder of the Cardium HSU, precluding the availability of data for hydraulic head mapping. The location of water wells and oil and gas well drillstem tests used for mapping hydraulic head is displayed on an inset map.

The uncertainty of prediction is depicted on an additional inset map, which shows the residual values (predicted value minus measured value) plotted at each location to indicate where underprediction or overprediction occurs.

Two additional inset maps show the distribution of total dissolved solids (TDS) and the results of water driving force analysis, respectively. The geometry and variable thickness of the Cardium HSU are illustrated on schematic cross-sections. The regional lithostratigraphy and hydrostratigraphy of the Cardium HSU and overlying and underlying units are highlighted in a table.