Abstract
The production of unconventional gas plays including shale gas and coal bed methane is rapidly increasing as a new energy resource in Alberta, Canada. Horizontal drilling in combination with hydraulic fracturing is making it possible to produce from tight formations. There are concerns as to negative potential impacts from hydraulic fracturing, making it important to conduct a shallow groundwater baseline study to determine the source of gases in shallow groundwater against which future potential impacts can be compared. In this study, 124 samples from 66 groundwater monitoring wells collected from 2006 to 2014 were assessed for geochemical and isotopic compositions. Methane was found to be ubiquitous in groundwater throughout the province of Alberta while ethane was present in shallow groundwater samples often only in very low concentrations. Based on isotopic compositions and concentration data it was possible to determine that the origin of methane in shallow groundwater is mainly biogenic.
