Towed Streamer EM Acquisition

The towed streamer system deploys an electromagnetic receiver cable at down to 100 m depth and a powerful horizontal dipole source at 10 m depth. A specially coded broadband source creates an EM field which penetrates the earth, and highly sensitive receiver electrodes housed in the streamer detect fluctuations in the field from which subsurface resistive anomalies can be derived. Acquisition speed is comparable to 2D seismic, yielding very high efficiency, especially for regional surveys.

Simultaneous Acquisition of EM and GeoStreamer®

For the ultimate in exploration efficiency and risk mitigation, the PGS Towed Streamer EM system can be towed simultaneously with GeoStreamer. This permits fast data acquisition (up to 5 knots), of both 2D broadband seismic and high-density 3D EM, from a single vessel.

Both datasets are QC'd and processed onboard, to produce inversion-ready field data, which can be inverted and then integrated for interpretation on a regional and/or prospect scale. PGS has demonstrated the efficiencies gained using simultaneous acquisition projects in the Celtic Sea (south of Ireland) and in the Barents Sea. 

Schematic showing simultaneous EM and GeoStreamer acquisitionSimultaneous EM and GeoStreamer acquisition

 

EM only acquisition

In mature areas, where seismic data already exists, the PGS Towed Streamer Electromagnetic system can gather EM only date. The system is easy to deploy and highly flexible. In 2014, PGS used a third-party vessel to acquire high-density EM data in the Barents Sea.

Specialized vessels are not required, as the operation is very similar to a towed streamer seismic layout. The degree to which a seismic vessel needs to be adapted to operate the EM system is minimal.

 

EM only - deployed in areas of existing seismic dataEM only acquisition