Technical Content

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 ...

The Point Thomson field, located on the North Slope of Alaska, covers the transition zone from onshore to a frozen lagoon. This complexity in the near-surface poses many challenges to proper imaging of the reservoir. Unground ice on the lagoon causes very poor signal-to-noise ...

Although wavefield extrapolation techniques are well developed for P-wave seismic imaging, ray based migration algorithms are still the workhorse for converted-wave (PS-wave) depth imaging. Full (exact) elastic-wave reverse-time anisotropic migration (RTM) has not been widely adopted for reasons of computational and workflow efficiency, despite ...