Linear low-frequency sweep vs customized low-frequency sweep

The technique of blended acquisition with dispersed source arrays becomes an efficient simultaneous shooting method recording broadband data in land Vibroseis acquisition. Each vibrator or each group of vibrators is specified to cover certain narrow frequency bandwidth. For the low frequency band (< 10 Hz), the vibrator is often driven using a customized low frequency sweep to prevent the vibrator from reaching its physical limits. Consequently, this customized low frequency has to be designed with small amplitudes and a long sweep length. The long sweep length potentially downgrades the productivity using this blended acquisition technique. This paper attempts to present a new low frequency limits control technology, embedded as a vibrator control firmware, can enable the vibrator to produce more force using a linear low frequency sweep than using a customized low frequency sweep. Experimental tests show that at least a 5-dB improvement on the ground force has been seen with the low frequency limit control at the low frequency range (< 10 Hz). Presentation Date: Tuesday, October 18, 2016 Start Time: 10:45:00 AM Location: 163/165 Presentation Type: ORAL