Over 40,000 vibrator points per day with real‐time quality control: opportunities and challenges

To evaluate high-density source and receiver land seismic acquisition designs, two sets of simultaneous highproductivity vibroseis field tests were performed in a relatively flat terrain area with good signal-to-noise ratio. These included distance separated simultaneous sweeping (DSSS) (Bouska, 2009), slip-sweep (Rozemond, 1996), distance separated simultaneous slip-sweep (dynamic slipsweep) and independent simultaneous sources (ISS) (Howe et al., 2008) with unique sweeps. The second dynamic slipsweep field test used a 29 km active fixed super-spread (12 receiver lines separated by 300 m) with 20 point vibrator fleets on a 25 m x 25 m source grid. A group of 10 point vibrators were oriented orthogonal to the receiver spread in the North and 10 in the South direction with a lateral separation distance of 14.5 km. This method achieved 30,346 vibrator points (VPs) in a 24 hour period. The same fixed active receiver spread was reduced to continuously record two unconstrained simultaneous sources (microseismic mode) in 18 sectors (3x6). Each sector was 1.8 km x 1.8 km with 4,320 VPs on a 25 m x 25 m source grid (77,760 total VPs) with 18 unique 12 s pseudorandom sweeps (Sallas et al., 2008) and repeated with 18 unique linear upsweeps (14.5 s average sweep length) from 5 to 110 Hz. We achieved optimum productivity rates of 45,501 and 44,793 VPs per 24 hours, respectively, with real-time quality control (QC) – we were not sweeping blind. Seventy two drivers were organized in three eight-hour shifts along with four vibrator pushers per shift. Three helped with fleet management and one for TDMA real-time communication between the vibrators and the recorder. Even higher productivity rates could have been achieved with stakeless guidance training of the vibrator drivers and pushers.