In 2012 the Alberta Geological Survey (AGS) released an Open File Report (OFR 2012-06) on Alberta’s shale- and siltstone-hosted hydrocarbon resources that included those in the Duvernay Formation. The 2012 assessment of the Duvernay Formation included only the very earliest test wells in the Duvernay and therefore made many assumptions about rock properties, water saturation, fluid distributions, and pressure and temperature regimes. There was also relatively little data available for determining net thickness, porosity, and total organic carbon.
New data have shed light on some of the earlier uncertainties resulting in improved assumptions and more precise hydrocarbon resources models. This work provides an update to the estimates of in-place quantities of natural gas, natural gas liquids, and oil in the Duvernay Formation. The new resource estimates were generated by geostatistically simulating the spatial variation of most of the relevant reservoir characteristics, including their uncertainty, over most of the Duvernay Formation extent. One hundred simulated realizations were then used to calculate the in-place resources and the associated uncertainty.
This work produced updated property maps (simulated realizations and means of 100 realizations) and quantities of hydrocarbons in-place. The estimates for the total in-place resources in the Duvernay Formation are 22.1 1012m3 to 24.2 1012m3 (784 to 858 Trillion Cubic Feet (Tcf)) of raw gas, with a best estimate of 23.1 1012m3 (820 Tcf); 14.6 109m3 to 15.8 109m3 (91.7 to 99.4 billion barrels (Bbbls)) of natural gas liquids, with a best estimate of to 15.2 109m3 (95.9 Bbbls); and 31.5 109m3 to 34.9 109m3 (198 to 220 Bbbls) of oil, with a best estimate of 33.1 109m3 (208 Bbbls). These are the total in-place resource estimates and do not take into consideration accessibility, recoverability, or economics. The in-place resources are very different than reserves, which are based on estimated recovery from projects currently in development or expected to be within a short time frame.
Lyster, S., Corlett, H. and Berhane, H. (2017): Hydrocarbon resource potential of the Duvernay Formation in Alberta - update; Alberta Energy Regulator, AER/AGS Open File Report 2017-02, 44 p.