Broadband Vibroseis Using Simultaneous Pseudorandom Sweeps

Simultaneous pseudorandom sweep technology (SPST) is a new method of Vibroseis acquisition. Carefully designed long pseudorandom sweeps that are mutually weakly correlated over a time window of interest permit source contributions to be separated. An advantage of random sweeps is the ability to create low-dwell sweeps without running the risk of overtaxing the vibrator hydraulic system. Since the sources tend to act independently, conventional correlation can be used for initial separation thereby permitting field QC of the process. A second separation using measured signals further suppresses crosstalk. We conducted a field test in Oklahoma using conventional, SPST and HFVS methods to develop subsurface images allowing a comparison of data quality and frequency content.