Sub-Basalt Imaging

West of Shetland

In order to achieve sufficient bandwidth in areas where high frequencies are limited, it is necessary to extend the low frequencies. Lower frequencies are affected less by attenuation, and provide greater accuracy and stability for seismic inversion.

Conventional marine streamer acquisition lacks sufficient signal-to-noise ratio in the 2-7 Hz bandwidth due to streamer depth, streamer tow noise, source array configuration, source depth and source bubble. Using BroadSeis we routinely record frequencies down to 2.5 Hz, providing three octaves of data below 20 Hz.

Sub-B BroadSeis Sub-B Conventional

Slide to compare

sub-basalt WoSIn trials West of Shetland, BroadSeis shows superior sub-basalt imaging and penetration. In the example above, the marked reflector fades away beneath the thicker basalt towards the northwest (left) on the conventional section. Only the lower frequencies provided by BroadSeis penetrate the basalt, allowing the reflector to be traced across the entire section. There is also improved fault definition (center) on the BroadSeis data as well as significant improvement to the S/N ratio at depth.

Zooming in around the top and base basalt (right) shows the clearer definition of this layer on the BroadSeis data. We can see the base and intra basalt layers, including probable multiple basalt flows pinching out.

Uses of wide-azimuth and variable-depth strea...

Fabrice Mandroux | Robert Dowle | Jo Firth | Gareth Williams
©2011 EAGE

Sub-basalt Multiple and Noise Suppression Usi...

Richard Wombell | Gareth Williams | Christopher Winter | Krz...

Experiencing the full bandwidth of energy fro...

Jo Firth | Idar Horstad | Menne Schakel
©2014 EAGE
Offshore - Low Frequency Recording

Ultra-Low Frequency Recording

See below salt and basalt. Build better reservoir models. Record useful data down to 2.5 Hz with Sentinel.
Offshore - BroadSeis Subsalt

BroadSeis Subsalt

The broad bandwidths with ultra-low frequencies achieved by BroadSeis are ideal for subsalt imaging without compromising high frequency shallow resolution.
Offshore - Complex Geology Solutions

Complex Geology Solutions

Tailored multi-vessel acquisition solutions can deliver enhanced illumination beneath complex geologies, with improved noise and multiple attenuation.
Offshore - Bespoke Multi-Vessel Solutions

Bespoke Multi-Vessel Solutions

We tailor our acquisition to meet your specific geological or operational challenge, don't settle for a one-size-fits-all survey.
Offshore - Products and Solutions

Offshore Products & Solutions

Advanced technologies and innovative solutions to address your acquisition challenges - increase resolution, enhance illumination and improve efficiency.
Offshore - People and Service

People and Service

Our experienced people make the difference, being knowledgeable, reliable and open, with the resources and expertise to go the extra mile.

Offshore (Marine)


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