This data release contains water chemistry data used to create a total dissolved solids (TDS) map of the Wabamun hydrostratigraphic unit (HSU) as part of the Alberta Geological Survey’s (AGS) Provincial Groundwater Inventory Program. The source data are water chemistry analysis data from oil and gas well drillstem tests (DSTs) and production fluid samples.
Data have been processed, relevant records selected, and outliers removed to compile this dataset. The dataset consists of a file containing calculated TDS values.
All attributes for oil and gas wells are as received from the data source. The total dissolved solids (TDS) values are calculated from other fields and do not contain any decimal places. Calculation of TDS is dependent on the measurement of the availability of specific ions at the time of testing and the generally accepted standard for displaying TDS is a whole number.
The mid-point of the sampled interval is also a calculated value and its accuracy is dependent on the accuracy of the measured depths and elevations provided from the well header. For oil and gas wells, the well elevations and locations are surveyed, so accuracy will be to the same significant digits provided by the source, even though there may be considerable uncertainty as to where the sample actually came from.
Data containing chemical analyses were obtained from formation water analyses from oil and gas well DSTs and production fluid samples.
DST and production well data, current up to 2017 (test dates ranging from 1950-2009), were used to provide chemical information for the deeper groundwater system.
Process steps for selection of chemical analysis from oil and gas wells:
1. Records that have values for interval top and bottom were selected.
2. The screen interval was constrained to less than or equal to 50 m.
3. Acceptable charge balance error was constrained within plus or minus 10%.
4. Samples labelled as “incomplete analysis" were removed.
5. Records were allocated, and selected if they were within the Wabamun HSU.
6. In the case of duplicate samples, the water analysis with the best sample location was used.
The remaining formation water analyses were subjected to additional screening to identify potential contamination of the formation water by drilling fluids such as acid water, corrosion inhibitors, mud filtrates, and alcohols.
Details about the screening process can be found in the following reference: Jensen, G.K.S., Rostron, B., Palombi, D., and Melnik, A. (2013): Saskatchewan Phanerozoic Fluids and Petroleum Systems project: hydrogeological mapping framework; in Summary of Investigations 2013, Volume 1, Saskatchewan Geological Survey, Sask. Ministry of the Economy, Misc. Rep. 2013-4.1, Paper A5, 10 p. URL http://publications.gov.sk.ca/details.cfm?p=80100 [October 2018]