An automated system for preventing hydraulic vibrator tip-over during land seismic surveys

Hydraulic vibrators are the preferred source for land, seismic surveys. The energy from the vibrator's signal, (commonly referred to as a sweep) is transmitted into the, ground via a baseplate that is coupled to the surface by, loading it with the weight of the vehicle. The baseplate is, lowered into position by a stilt structure which continues, to apply hydraulic pressure to ensure that the baseplate, does not become decoupled from the surface during the, sweep (the ground beneath the baseplate often becomes, slightly compacted). If the vibrator is operated on a slope,, or if the ground gives way in a significant and uneven, manner, then the vibrator can continue to extend the stilt, structure which in extreme cases can cause the vibrator to, tip-over., In this paper we describe a system developed by Terrex, and Seismic Source, consisting of two inclinometers and, an articulation sensor that can be fitted to a vibrator to, automatically retract the baseplate when the vibrator, becomes overly tilted. The system was recently deployed, on a large 3D survey consisting of over 100,000 source, points. Of these source points, 171 were skipped due to, the tilt of the vibrator exceeding the safe limit. Analysis, of a LiDAR dataset showed that of these 171 points, less, than 3.5% of crossline and 3.1% of inline dips exceeded, this 'safe' limit. Indicating that if the LiDAR data had, been utilised during the planning phase of the survey most, of these positions would not have been excluded., The success of the system on this initial survey has led to, it being adopted throughout the Terrex fleet.