GeoStreamer®
– A Step Change in Marine Seismic
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The GeoStreamer gives better penetration, enhanced resolution
and improved operational efficiency |
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In June 2007 PGS launched a unique dual-sensor streamer to significant acclaim and market interest. Conventional streamers only record the pressure wave which is a combination of up- and down-going waves. The water surface acts like a perfect mirror and sends back, with a reverse polarity, all the waves that are emerging from the depths of the earth. This phenomenon generates interferences that are particularly damaging for some frequencies. To mitigate this problem conventional streamers are towed relatively shallow, which preserves the higher frequency range at the expense of weaker low frequencies.
The GeoStreamer® contains velocity sensors (geophones) in addition to the standard pressure sensors (hydrophones). The collocation of these two sensors allows for the separation of up-going and down-going waves. The water surface interferences can therefore be eliminated and the entire frequency range is preserved. Consequently the GeoStreamer® can be towed at a greater depth, which offers a quieter environment and an improved signal-to-noise ratio. This in turns increases operational efficiency due to the extended weather window.
The larger bandwidth means both better penetration, which is particularly appealing for deep, sub-salt or sub-basalt exploration and higher resolution, which benefits complex stratigraphic plays. In addition, the up- and down-going waves can be used in combination to improve attenuation of multiple energy and imaging of the subsurface. The GeoStreamer® technology is now field-proven, rugged and only has upsides. By all accounts it represents a step change in marine seismic.
