Seismo-Acoustic Characterization of a Seismic Vibrator

A seismic vibrator generates seismic and acoustic noise as soon as it is pressured up and located in the proximity of a recording spread. The noise in the seismic bandwidth is more critical in vibroseis surveys where a large number of vibrators are used as in the case of simultaneous acquisitions. The noise in the acoustic bandwidth is particularly important when the survey takes place in populated areas. We carried out a seismo-acoustic experiment to characterize these noises. We present the results obtained while the vibrator is pressured up but not sweeping, with the baseplate in contact or not with the ground. We demonstrate that several monochromatic noise components can be related to the cooling and exhaust systems. We also show the effects in the seismic and acoustic bandwidths of modifications to the cooling and exhaust systems.