Well-logging and Near-surface Seismic Methods for Aquifer Detection

Well-logs, high resolution shallow seismic, and VSP surveys were conducted in a experimental well near Priddis, Alberta, to test their feasibility in characterizing the near-surface stratigraphy and hydrogeological characteristics of the Paskapoo Formation. According to the analysis of well logs, the well penetrates interbeds of sandstone-shale layers and five porous zones were identified at depths of 28, 39, 50, 62 and 120 m, ranging from 0.34 to 0.58. Among these porous zones, there were three water-bearing zones at depths of 28, 50 and 120 m. Based on the P-wave velocities calculated from the sonic log, surface-wave analysis was carried out to estimate S-wave velocities. Up to depths of 40 m, the respective P-wave velocities for the sandstone and shale units were 2250 m/s and 2080 m/s, and 1220 and 1150 m/s for the S-wave, respectively. Using a microphone-geophone analysis, the airwave was characterized by high frequency and broadband. The integral interpretation of all the datasets and well-logs show a good correlation between all of them. The water-bearing zones (28 and 50 m) and the strong reflector at 76 m were resolved by the surface seismic and VSP data.