Dovetail
Efficient Streamer Acquisition of High Quality Data
Dovetail™ is an efficient streamer acquisition solution, especially where there is significant and unpredictable feathering. Dovetail significantly reduces the need for infill while remaining within bin fold specifications, leading to reduced survey time and HSE exposure and faster data receipt, with no degradation of data quality.
Why Use Dovetail?
Dovetail combats poor far-offset fold coverage due to extreme feathering, caused by such things as strong local currents etc, by using three interlinked components:
- Acquisition:
- Fan-Mode streamer acquisition by Nautilus, which can be programmed to produce a fanned spread automatically
- Variable Bin Expansion (VBE)
- applied to onboard binning to facilitate vessel steering for maximum coverage.
- Processing:
- Trace interpolation using an intelligent anti-leakage Fourier algorithm
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Using Dovetail acquisition there is no reduction in the fold specifications for the survey, these are just fulfilled more efficiently |
- Meets binfold specifications for survey with a drastic reduction in infill/prime ratio (current pattern-dependent)
- Reduced survey time
- Faster data receipt
- Reduced HSE exposure
- No reduction in data quality
- Reduced infill means less “wasted” duplicate acquisition and therefore increased processing efficiency
- Smaller holes in the data for safer interpolation
- Better sampling at mid/far offsets
- Large reduction in real-time steering/overlap
- Sail for pre-plot/near offset to achieve higher resolution
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After interpolation, if we compare the timeslice over the conventional/Dovetail join with the fold of coverage map, it is impossible to see on the seismic where the conventional acquisition (with 40% infill) ends and the Dovetail (with 7% infill) begins |
Interpolation
Since higher frequencies are attenuated at longer offsets and greater depths, Dovetail allows larger interpolation distances at longer offsets by increasing the streamer separation towards the tail of the streamers. Using a de-aliased anti-leakage, irregular Fourier transform and an advanced algorithm for the interpolation means that there is no degradation of the data.
REVIVE5D uses the true source and receiver locations of the data, preserves amplitudes across offsets and azimuths accurately, and thus honours the true 3D character of the data (important in areas of significant feather).
