High Resolution Short Offset 3D

Fugro Seismic Imaging Limited (FSI), has developed a technique that is designed for maximum preservation of the integrity of the shallow seismic data for precision three-dimensional imaging. Fugro Seismic Imaging Limited has named this technique "Short-offset Processing". The method provides greatly improved temporal and spatial resolution in the shallow seismic section and is used to reprocess volumes of 3D seismic data normally acquired for conventional seismic exploration purposes. Thus huge value is added with a relatively small investment in reworking the data; the major acquisition spend has already been made. The Short-offset 3D product is ideal for the detailed mapping of shallow reservoirs and can be used in near-surface risk analysis prior to exploration drilling or development design. The processing methodology has also been used extensively in the processing of 'true' 3D site surveys, where the data has been acquired with typical site survey acquisition parameters.

Benefits of the Short-Offset approach include:

• Cost effectiveness - Can be applied during acquisition, to current 3D projects or older 3D datasets
• Safety - Fast-track evaluation of possible subsurface geohazards
• Rapid turn-round - Early identification of proposed drilling sites
• Licensing tool - Can be submitted in support of development applications
• Integrated geoscience - Increased resolution provides better calibration with borehole data

• Data are processed as 'true position' throughout, avoiding unnecessary binning 'smear'
• Diffractions are correctly collapsed, also removing a major source of 'smear'
• Data are processed as 'true amplitude' throughout. No amplitude corrections are required
• The signal-to-noise ratio is recovered during the migration process
• Regularization of data distribution issues can be addressed using the Migration algorithm

• Steep and potentially unstable slopes (creep)
• Land slides
• Irregular sea floor
• Erosion and scour
• Under/over consolidated materials

• Faulting and slumping
• Buried channels
• Overpressure zones (gas or water)
• Natural gas hydrates.