Nodal acquisition provides you with the dense, wide-azimuth data that unlocks the power of sophisticated noise reduction and imaging technologies. From exploration to field development, imaging to reservoir characterization, it's important to follow through with the right processing techniques to help ensure you get a superior image.

Wavefield Separation

A patented process that outputs hydrophone, vertical geophone, upgoing and downgoing wavefields.  Special techniques significantly suppress V(z) noise on the vertical geophone while correcting for obliquity and coupling.

[Left] Vertical geophone before V(z) attenuation. <br />[Right] Vertical geophone after wavefield separation and V(z) attenuation.
[Left] Vertical geophone before V(z) attenuation.
[Right] Vertical geophone after wavefield separation and V(z) attenuation.

Directional Designature

Forming an accurate representation of the earth’s reflectivity requires a common source signature for every angle and azimuth for every shot in a survey.  Deepwater nodes provide a nearly perfect representation of the source wavefield at all angles and azimuths.  FairfieldNodal uses a patented technique to form a directional designature operator from the recorded source wavefield.

Multiple Attenuation

Wave-equation surface multiple attenuation (WEMA) is a model-driven technique requiring the earth as a model containing reflectors whose multiples must be attenuated. Here, the measured wavefield is propagated from the surface to the target reflector(s) and back, using finite-difference wave-equation modeling code. This way, the primaries are converted into first-order multiples, first-order multiples into second, and so on. Modeled multiples are then adaptively subtracted. 

No demultiple
No demultiple
Multiple removed
Multiple removed

Merging 3D Seismic Surveys

FairfieldNodal has vast experience merging multiple 3D surveys that were acquired independently but may partially overlap.  These surveys often have varying acquisition geometries and orientation.  We manage issues of geometry, phase, noise, amplitude, refraction and residual statics to correct for survey-dependent variations. Surveys are output to a common grid, using proprietary techniques to manage offsets, folds and amplitudes for AVO-compliant data.

The results of our approach are outstanding. We’ve already processed over 5,000 square miles of land and transition-zone data and thousands of square miles of OBC data.

Seismic Survey 1
Seismic Survey 2
Seismic Survey 3