The use of pseudorandom sweeps to reduce interference noise in simultaneous Vibroseis surveys

Abstract

The cost of land seismic surveys is largely reliant on the total acquisition time. If the total acquisition time itself is limited then we may need to compromise the parameters used for the survey and thus the quality of the data acquired may be reduced. To overcome the productivity limitations associated with conventional Vibroseis acquisition, simultaneous shooting, where fleets of vibrators sweep at different locations at the same time, has been employed. Such methods typically require that the number of sweeps acquired at each source position is equal to the number of fleets, thus reducing any increase in productivity. Despite the use of such methods the data may still contain significant levels of noise contamination. In this study we describe a new technique for generating sets of pseudorandom sweeps with cross-correlation attributes tailored to reduce interference noise. By using both synthetic and real data examples we show that such sweeps can significantly reduce the interference noise inherent in simultaneous shooting and thus have the potential to dramatically increase Vibroseis productivity without significantly affecting data quality.