Technical Content

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 ...

4D seismic processing is designed to minimize non-repeatable noise while preserving real 4D signal. Coherent noise, such as from surface and interbed multiples, has different character from one vintage to another. Mitigating for these unwanted effects in a vintage-independent manner leads to suboptimal 4D ...

A precise knowledge of the seismic source far-field signature is required for accurate source de-signature. Near-field hydrophone data can be used to provide good quality signatures but are not always available. We describe a method of extracting the far-field signature from inversion of direct ...

Changes in fracture direction across interfaces can have an important impact on PS-wave reflection coefficients in azimuthally anisotropic media. Extending conventional joint inversion with P-waves to include amplitude variations with azimuth (AVAz) would use radial and transverse reflection coefficients (RPSV and RPSH, respectively), and ...

We presented a joint tomography flow for OBN and streamer WAZ data in deep water Gulf of Mexico. This tomography provides the method to utilize surface offset gathers from surveys with different shot and receiver datums together for joint tomography. By incorporating both OBN ...