Distribution of Hydraulic Head in the Grand Rapids Hydrostratigraphic Unit

This map depicts the distribution of hydraulic head in groundwater in the Grand Rapids hydrostratigraphic unit (HSU). The map is a result of an ordinary kriging technique using publicly available data from Alberta Environment and Parks' (AEP) Alberta Water Well Information Database (AWWID) and formation water analyses from oil and gas well drillstem tests and production data.

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 and overprediction occurs. A Cumulative Inference Index (CII) methodology is 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 Grand Rapids HSU are shown on schematic cross-sections.