Controlled Beam Migration (CBM)

Depth Imaging in Complex Settings

Controlled Beam Migration (CBM) is an extension of Beam Migration technology, specifically targeted at imaging steeply dipping events and enhancing the signal-to-noise ratio of both land and marine datasets. CBM has the steep-dip imaging capabilities of Kirchhoff techniques while offering the multi-arrival abilities of wave equation migration.

CBM imaging results in improved signal-to-noise ratio, especially in sparse, low-fold land data. The migration algorithm can also be used to remove multiple energy as part of the imaging provess using a proprietary technique.

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CBM imaging of a fractured basement reservoir. Fracture and solution porosity are associated with major faults. Kirchhoff PSDM struggles to resolve these faults. Controlled Beam PSDM has been applied during re-processing of the data, and the combination of multi-arrical imaging, improved signal-to-noise and enhanced steep dips results in well-defined basement contacts and internal faults.

Features:

Imaging of multiple arrivals
Enhanced steep dip imaging
Faster model-building
Isotropic of Anisotropic (VTI or TTI)
Option to incorporate discrimination and suppression of multiples within the imaging process
Enhanced pre-stack data

Benefits:

Enhanced structural imaging and interpretation
Salt flank and base imaging
Sub-salt imaging
Steep dips and overthrust imaging
Fractured basement imaging
Improved signal-to-noise ratio, especially beneficial for sparse land data

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Signal Enhancement in Land Data

Comparison of low-fold land data acquired over a salt structure in northwest Europe. The Kirchhoff image is noisy due to the low fold and sparse mid-far offset coverage, while the CBM image benefits from greatly improved signal-to-noise ratios. The base of salt and the sub-salt target horizons are images much more clearly with CBM.

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Controlled Beam Multiple Attenuation

As part of the migration algorithm, multiples of specific horizons may also be modelled and attenuated using a proprietary technique.

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Kirchhoff	CBM	CBM Demultiple

In this example from the North Sea, the target fault blocks below the Base Cretaceous Unconformity are obscured by multiples and noise in the Kirchoff migration. After CBM the fault blocks become clearly identifiable. After CBM incorporating de-multiple, the multiples below the unconformity have been attenuated so that the dipping primaries and fault planes become clearly defined.

Data courtesy of Total E & P UK.

Comparison of Kirchhoff, CBM and CBM Demultiple