HFVS™: Enhanced data quality through technology integration

Abstract

Known problems with vibroseis data include difficult-to-pick and inaccurate first-arrival times, poor well ties, correlation side lobes, harmonic ghosts, and coupling differences. Also, to reduce acquisition costs, various methods are used to record and then separate data from different source locations using vibrators sweeping simultaneously, but these methods suffer from poor data separation and harmonic contamination. A novel combination of heritage Mobil High Fidelity Vibratory Seismic (HFVS) and heritage Exxon vibrator technologies solves these problems with vibroseis data. The method involves vibrator separation combined with vibrator signature deconvolution in such a manner that the output is minimum phase and matches impulsive data. Vibrator signatures are calculated from the vibrator accelerometer measurements. The signatures from multiple vibrators and multiple sweeps are used to design a filter that optimally separates the data from each vibrator and replaces the signatures with a specially designed impulse response. Specific procedures are included to reduce the effects of inversion noise, which can distort the phase. HFVS recording can be used to increase production rates and reduce acquisition costs or to increase spatial sampling and improve data quality. Data recorded from multiple vibrators sweeping simultaneously can be separated by at least 60 dB. After separation, the data from each vibrator can be processed as unique source points. Compared with traditional vibrator arrays, individually processing each source point can result in better data quality by reducing intra-array effects and improving the mitigation of ground-roll noise.