Integrated geological and seismic site characterization at Priddis, Alberta

J. Helen Isaac, Donald C. Lawton

3C2D and 3D seismic data were acquired during field school in the last few years on and near university lan ds at Priddis, Alberta. The data were acquired so that we may characterize the shallowest 800 m for the purpose of future experimental CO₂ injection. Sandstones identified on gamma ray logs are assumed to be correlatable with sandstones observed in outcrop in the west of the study area and to strong reflectors seen on the seismic data. Two sands, termed the Middle Paskapoo and Lower Paskapoo, are interpreted to lie at depths of around 440 and 770 m below the surface, respectively, in the centre of the 2010 Priddis 3D survey. The Lower Paskapoo sand is of particular interest as it is under cons ideration for CO₂ injection. A robust static geological model was developed for the site and several scenarios of CO₂ injection were simulated for cas es of low and high reservoir permeability, and assuming a porosity of 8%. At low injection volumes (600 tonnes per year) the maximum free-phase CO₂ pl ume diameter after 5 years of injection is only 140 m, and updip migration over 100 years of shut is minimal due to solubility, residual and mineral t rapping.