A multicomponent seismic survey at Calgary International Airport, Alberta

Donald C. Lawton, Robert R. Stewart, Malcolm B. Bertram, Henry C. Bland

A 2.4 km multicomponent seismic line was acquired near Calgary International airport to evaluate Vibroseis source and receiver parameters for recording P-S data. A series of source tests was undertaken using one and two vibrators, several different sweep lengths and frequency bandwidths. Linear as well as and non-linear sweeps were also evaluated. Reviews of the source tests indicated that 2 vibrators were required to obtain visible reflections from basement rocks (1.8 s P-P time). Optimum source characteristics for P-S data were found to be a non-linear sweep (-3 dB/octave) from 6 Hz to 100 Hz over 12 seconds. Vibrator separation was also tested in a 'walkaway' experiment to evaluate this source parameter on data quality. Conventional 3-C geophones as well as new '3-C nails' were also tested. One test line processed to date indicates P-P reflections with bandwidth over the full spectrum of the source sweep and P-S reflections with bandwidth from 6 Hz to approximately 60 Hz.