Brooks revisited

J. Helen Isaac, Donald C. Lawton

The first CO₂ injection well was drilled in 2015 at the Containment and Monitoring Institute’s Field Research Station near Brooks, Alberta. We used well logs from the new well to compare our pre-drill depth estimates of formation tops with those encountered in the well. Our estimate of the depth of the target Basal Belly River Formation, which we had derived from the seismic data interpretation tied to existing wells, was about 3.5 m high. We had also predicted a thin sand near the top of the Medicine Hat Formation and this prediction was 3 m high. Our predictions of the shale content in the Belly River Formation above the target injection zone are supported by gamma ray log and lithology data from the new well.

We created synthetic seismograms from the dipole logs acquired in the new well and tied them to the seismic data. The PP and PS data show good character matches between the seismic data and the synthetic seismograms. Although the seismic data did not require re-interpreting, we used the formation tops from the new well to revise the depth structure maps. We also updated the post-stack joint PP-PS inversion to 550 m depth by using the dipole logs from the new well.