Transition zones (coastal areas connecting marine and onshore) are known to constitute a hazard in seismic exploration. The establishment of accurate ties between various modes of seismic surveys (Land, Shallow Marine and Marine) should therefore be carefully considered/achieved during both data acquisition and processing phases.
Variations in water depth, sea bottom topography, the crossing of small islands and/or reefal bodies normally impose constraints on the selection of optimum data acquisition parameters. Flexibility/versatility of methods and equipment are of utmost importance in securing adequate results. Multi-various combination of energy sources (airgun, dynamite, vibroseis etc.) and receivers (hydrophones, geophones, marshphones etc.) could be used within the one and the same survey to secure maximum continuity of seismic reflections.
Seismic data acquired in the transition areas require the application of special processing parameters due to amplitude and phase distortion resulting from the use of various sources and receivers. Sophisticated and advanced processing techniques are therefore essential to generate continuous and well matched seismic sections across the transition areas.
Optimum processing results can only be achieved in case good quality data is acquired. This should enable better identification of subsurface structures and stratigraphie plays that may be present, and consequently enhance possibilities for the detection of hydrocarbons.
Seismic data acquired and processed through the application of new techniques undoubtedly reveal better definition and resolution of subsurface traps, when compared to data recorded using old methods.
All examples and illustrations presented in this paper were extracted from seismic data, acquired in ADNOC Concession Areas, in Abu Dhabi, United Arab Emirates.