Technical Content

One way to address the problem of weak subsalt illumination is through angle gather illumination weighting (AGILW). In this technique, synthetic data mimicking the field data are generated and migrated the same way as the field data. Illumination weighting scalars are obtained by measuring ...

The test showed that, in the central North Sea, with appropriate denoising, we were able to successfully remove SI from all azimuths down to a vessel separation of less than 25 km. By adjusting vessel speeds to make sure that SI did not arrive ...

We present an input data selection workflow based on 3D ray-tracing to improve the RTM image in areas of poor illumination and low signal-to-noise ratio. It is effective for imaging subsalt three-way closure with weak subsalt primaries and strong noise levels. The workflow can ...

Serial processing of PP and PS waves leads to depth inconsistencies between the PP and PS migrated images. The link between P- and S-velocity model is the Vp/Vs ratio, whose estimation is an important task in multicomponent analysis because of its applications to lithology ...

Discusses use of simultaneous-source acquisition for sparse (ROV-deployed) OBN surveys, using time and motion studies to quantify impact on acquisition time. Also describes new technique for sim-src crosstalk noise attenuation using modified Radon operators. Finally, application to Gorgon OBN data for baseline and monitor ...

Multiple timelapse realisations produced using wavefield separation, data selection, or diverging processing flows are combined using powerful noise-reducing data weights formulated using the 3D images as well as the 4D differences. The result separates 4D signal from incoherent 4D noise and also 4D noise ...

In the context of WAZ data the VTI hypothesis is not always sufficient for insuring focusing of time migration. We propose an extension of non-linear slope tomography for time imaging to the orthorhombic case. We use a model of orthorhombic anisotropy parameterized by five ...

The seismic image represents the spatially variable reflectivity of the medium where migration effectively rotates the wavelet to be normal to the imaged reflectors. While this is the general case, it is often disregarded, and one-dimensional spectral analysis of the vertical coordinate is commonly ...

Estimation of primaries by sparse inversion (EPSI) is an iterative method that effectively separates primaries and surface-related multiples, especially in shallow water. Multiple attenuation in shallow water is challenging, mainly because of acquisition limitations. We propose a strategy for EPSI with the following objectives ...