Extending the Vibroseis Acquisition Bandwidth with a Newly Designed Low Frequency Seismic Vibrator

Acquiring low frequency data using Vibroseis technology can be very beneficial for land seismic exploration. Unfortunately, because of physical limitations in vibrator mechanical and hydraulic systems, most conventional vibrators cannot produce sufficient ground force at low frequencies. To successfully push Vibroseis acquisition bandwidth into the lowest frequency range (< 5 Hz), the vibrator output force must be significantly increased. An improved design of vibrator actuator becomes necessary. This paper attempts to present a newly designed low frequency vibrator. Experimental results show with this new low frequency vibrator the vibrator ground force at low frequencies is significantly improved. Downhole data at the depth of 7500 ft (2288 m) demonstrate that a measurable force-energy from 0.5 Hz to 131 Hz (8 octaves) is achieved with this new generation low frequency vibrator.