The key difference PGS’ vibrator has to other designs is that the densely stacked plates significantly increase the total surface area while minimizing the overall unit size. Sufficient sound pressure is produced at the crucial lower end of the frequency band at operational depth. Accurate control of system resonance means the structural load of the vibrator is secure. So far, the design has proved itself robust and reliable during both a 1 000 hour tank test, and at full power at depths of 60 meters in a harbor. The next step will be to perform a geophysical test comparing data results to PGS MultiClient data acquired with a traditional source.

The eSeismic Approach, Quieter and More Efficient

The eSeismic method can be used with either marine vibrator technology or with standard air source elements to provide a quieter environment for fish and sea mammals. While the standard seismic method uses a simultaneous array of 30 air source elements, eSeismic uses only one at a time. It releases an alternation of 40, 90, and 150 cubic inch source elements several times a second to generate a continuous wavefield. Sound exposure and peak sound pressure levels are significantly reduced compared to standard methods which typically releases 4130 cubic inches of compressed air every 10 seconds.

The eSeismic method provides a quieter environment for fish and sea mammals, which is the primary environmental benefit of this method.

A recent field trial offshore Brazil showed significantly lower sound pressure levels than traditionally produced. The viability of eSeismic in assessing deep geological layers was successfully proven and commercialization work is ongoing. PGS plans to acquire more eSeismic data in 2020.

Development of eSeismic technology has been supported by the Research Council of Norway through the Demo2000 program in collaboration with Equinor.