VSP and well logs from the U of C test well

Joe Wong, Soo-Kyung Miong, Eric V. Gallant, Henry C. Bland, Laurence R. Bentley, Robert R. Stewart

Shallow VSP and geophysical well logging surveys were conducted in a 127 m-deep well drilled at the Rothney Astrophysical Observatory site near Priddis, Alberta. The well was drilled through interbedded sands and shales of the Paskapoo formation. A contractor obtained a suite of well logs (including natural gamma-ray, single-point resistance, focused-beam resistivity, density, neutron-neutron, caliper, temperature and SP) in the open hole immediately after drilling. After PVC casing was inserted into the well and grouted to the formation rocks, we obtained natural gamma-ray and fullwaveform sonic logs. For the VSP surveys, we used a 5.5 kg sledge hammer source with a downhole clamping 3C geophone and an eight-element hydrophone array. From the full-waveform sonic logs and VSP data, we determined P-wave velocities to lie between 1.7 to 3.0 km/s.