Investigation of Devonian unconformity surface using High Resolution Legacy Seismic profiles, NE Alberta, Canada

摘要

The Devonian Grosmont Formation in northeastern Alberta, Canada is the world's largest accumulation of heavy oil in carbonate rock with estimated bitumen in place of 64.5×10~9 m~3. At the study location the eroded and buried surface of the Grosmont refers as the Devonian unconformity. This unconformity is a key to the development of the Grosmont resource because the resource abuts the unconformity. Using legacy seismic data and available well log information we were able to define the Devonian unconformity as a mature karst surface within observable features such as dolines, karst valleys, karst plain, a Poljie and a ridge. The Dolines and karst valleys and other such dissolution features have the potential to erode the bitumen reservoir of the upper Grosmont members. Mapping and avoiding areas such as the dolines and karst valley are highly important for oil prospectors to increase certainty of reservoir presence.