Simultaneous Sourcing Without Compromise

The use of high-efficiency simultaneous sourcing methods results in a signal-to-noise compromise. Noise arises because multiple seismograms need to be recovered or separated from a smaller number of vibroseis field records compared to methods, such as HFVS (High Fidelity Vibratory Seismic), in which there are as many sweeps as there are vibrators. We show that iterative methods can improve the separation and remove noise for seismograms recorded with multiple vibrators operating simultaneously with a single sweep. The iterative methods start with an initial separation. Then, updated seismograms are produced by adjusting them to match the survey data and to satisfy characteristics of noise-free seismograms. The match to survey data involves reconvolving parts of the initial seismograms with an estimate of the vibrator signatures and stacking. The method is especially effective at removing the noise at the bottom of records for Continuous-HFVS SM (Krohn and Johnson, 2005). With these iterative methods, the full efficiency of simultaneous sourcing can be obtained without a noise compromise.