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LARGEO is one of the leaders in advanced seismic data processing for challenging onshore environments on the highly competitive Russian market. We have the tools, expertise and extensive experience to take on the most difficult land imaging projects. LARGEO offers a variety of innovative amplitude and bandwidth preserving techniques that increase seismic resolution, enhance signal-to-noise ratio and ensure development of detailed and more accurate seismic images that eventually increase the confidence level of seismic exploration for our clients.

Noise Attenuation

LARGEO applies a variety of GXT algorithms to attenuate most types of noise found in marine and land data. The core algorithm “swdnoise” is a frequency- dependent, data-adaptive method capable of attenuating spikes, noise bursts, and swell noise. For organized or coherent noise such as cable strum, guided waves, and ground roll, GXT offers modeling in the FK, FKK, Radial-trace, or Tau-P domain, followed by adaptive matching and subtraction in all domains (RP, SP, CDP, Cross-spread in Common Offset panel).

High-Resolution RADON Demultiple

Developed by GXT. LARGEO performs a variety of different parabolic RADON multiple attenuation algorithms including the true “high resolution” varieties. A Gaussian Beam option is available for improved handling of aliased and sub-optimally spatially sampled datasets. This algorithm avoids the need to precede the transform with a dedicated interpolation.

Residual Velocity Analysis.

LARGEO offers a range of GXT residual velocity correction tools, including second- and fourth-order as well as trim-static based approaches. Correcting for residual moveout at large offsets (hockey sticks) by estimating weak anisotropy through ‘eta’ analysis enables exploitation of the data out to further offsets than is possible with only second-order techniques. For AVO-sensitive objectives, we offer AVEL (patent owned by BP), which estimates an optimum velocity using AVO methods rather than stack power. Employing RMO analysis and correction techniques can not only deliver high-resolution velocity fields, but also conditions gather for AVO analysis and geopressure prediction.

Data Regularization and Interpolation

using GXT technology. Regularization attempts to adjust the recorded data to more nearly match the assumptions of the migration algorithms, with a consequent improvement in amplitude fidelity and reduction in noise. GXT current implementation on marine 3D imposes regular spatial sampling on each cross line.  Traces are adjusted to bin centre and empty bins interpolated from neighbouring data. The method works in the frequency domain and employs a combination of compressive anti-leakage and anti-aliasing conditioning technology to handle both regularization and high bandwidth interpolation. The method can be applied in Common Offset domain, OVT (Offset Vector Tile domain (preserves azimuth) and in Cross-spread domain/ The method is successfully applied by LARGEO for processing of Algerian and Samara region data.

Azimuthal Velocity Analysis

Using GXT AZIM technology (Winner of the 2003 Hart’s E&P Meritorious Award for Engineering Innovation). Robust, high density (spatial and temporal) velocity analysis applied for the petroleum basins impacted by subsurface anisotropy which causes seismic velocities to vary according to compass direction (or azimuth). Unless properly accounted for, anisotropy degrades seismic image quality. As E&P companies search for hydrocarbons in more complex reservoirs, a highly accurate image of the subsurface becomes essential to success. The AZIM imaging solution improves image quality by taking anisotropy into account, allowing geoscientists to more accurately map subsurface features, identify fault and fracture patterns and optimize drilling locations.


Absorption effect (Q-factor) characterizes the loss of high frequencies in seismic data traveling through the earth with increasing travel time due to the earth’s filtering effect. The Q-factor can be estimated from seismic data by calculating the spectral ratio method that compares amplitude frequency spectrum of reflections at various times. LARGEO applies effective algorithms to derive and apply detailed time and space variable Q factors.

Static Correction

For static corrections Largeo employs the entire series of products Epos 3, Epos 3SE Paradigm Geophysical, for 2D/3D seismic data processing (Focus 5.2, Focus 5.3, GeoDepth), ION GXT static correction modules, Seismic Studio (RENEGADE Geophysics) and Millenium (GMG) packages allowing tomographic speed measurements based on the first arrival recorded data packages.

Largeo will provide:

  • Calculation of static corrections based on the wave refractions
  • Accounting for the depth-velocity model, based on the first arrival recorded data packages, during the creation of depth-velocity migration model
  • Static correction and velocity model using a layered nonlinear tomography.

To account for the near-surface velocity anomaly, which determine the accuracy of seismogeological output, Largeo offers effective technology that accounts for the refractory statics employing Seismic Studio software package, produced by RENEGADE Geophysics and GMG. Complex application of algorithms for calculating static corrections for the first arrivals of refracted waves, imaging algorithms,  beam and wave migration in solving the inverse problem will assist in extracton and use of information regarding the irregularities i and receive seismic cross sections with the correct geometry of geological structures and boundaries.

Stacked section before (left) and after (center) residual static corrections, and result of application of various static correction methods (right)

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