BroadSource

A synchronized multi-level broadband source

BroadSource^TM extends the spectrum to the ultra-high frequencies for better resolution and clearer images of the subsurface. It is a synchronized multi-level source which, combined with specially developed processing algorithms, eliminates the source ghost notch while providing the same low frequencies as our deep-towed conventional source.

Broadsource provides over 6 octaves of signal in the shallow section (up to 200Hz), with ultra-high frequencies limited only by the Nyquist recording interval and the Earth's absorption.

BroadSource is extremely flexible and is compatible with all receiver acquisition techniques. To gain the full benefit from Broadsource to deliver ghost-free broad bandwidths, Broadsource should be deployed in combination with a broadband receiver deghosting solution, and is fully compatible with ocean bottom nodes, BroadSeis, straight slant or deep flat tow combined with GWE (ghost wavefield elimination).

Broadsource is widely commercially-available and can be deployed by all CGG vessels. It is a proven broadband source solution, CGG has acquired over 75,000 sq km of 3D data with Broadsource, in combination with various broadband receiver deghosting solutions.

Benefits:

• All the advantages of a conventional source:
  • reliable, adjustable and repeatable
  • deployable as a flip-flop dual array
• High-resolution, broad-bandwidth ghost-free seismic data (2.5Hz to anti-alias filter)
• Better resolution and clearer images of the subsurface
• Reinforces improved BroadSeis layer differentiation
• Enhanced shallow resolution, suitable for site surveys

Ghost-free broadband data

BroadSource uses air guns at different levels to defocus the source ghost, so that it can be removed by designature. The firing of the guns is synchronized so that the deeper gun fires as the down-going energy from the shallower gun reaches it, creating a consolidated, focussed, down-going wavefront. The up-going energy is unsynchronized and therefore delivers unfocussed ghost wavefronts, enabling attenuation of the ghosts by designature. This designature process requires the use of an accurate far-field signature, which we derive from recorded near-field hydrophone measurements by Full Source Characterization (FSC).

We believe that the best broadband solution in the marketplace today is the combined offer of BroadSource and BroadSeis for most geological and operational contexts. However, CGG can provide BroadSource as a standalone solution in combination with any receiver acquisition technique, based on customer preferences and the specifics of the geology and operational environment.