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Surface wave inversion (SWI) for S-wave velocity plays an important role in near surface characterization and PS-wave velocity model building for depth migration. A hybrid approach is proposed to reduce non-linearity for multi-modal inversion without a-priori identification of higher order modes. This method is applied to north sea OBN data and produce a shallow Vs model that penetrates 120m depth below seabed. Vp/Vs ratios are then calculated as a powerful tool for near-surface characterization. SWI provides a high-resolution shallow Vs model which complements the weakness of PS-wave tomography in illuminating the near surface.

The compensation of absorption loss inside the imaging process using attenuation models estimated by Q-tomography is now widely accepted and used in the industry. This technology becomes even more important in the case of a complex dataset. For the Martin Linge field, characterized by a strong presence of faults and gas clouds, the multi-azimuth broadband acquisition involving a variable-depth streamer has helped to improve the quality of the data. High-end processing and imaging so far provided an image with enhanced resolution compared to legacy data mainly with regard to faulting in the deeper area. Nevertheless, imaging remained poor in the deeper part of the section because of a seismic obscured area (SOA) caused by gas clouds. In this paper we now illustrate how we managed to enhance the resolution under this SOA zone using volumetric Q-tomography and Q-prestack depth migration (Q-PSDM). In other words, we show that multi-azimuth broadband acquisition combined with Q-tomography/Q-PSDM techniques can provide an improved final image in the case of a complex data with a SOA.

Self-published 12-page White Paper on the subject of National Data Repositories. Distributed at NDR conference in June 2017.

TopSeis is a radically new solution for seismic acquisition and imaging, developed through collaboration between an oil company and the service sector.

Integrated exploration, new workflows for new challenges highlighting JumpStart Gabon, Marine Source Predictions and Encontrado reprocessing projects.

An automated and real-time field PSTM system, called TeraMig, was applied during the acquisition of a land 3D WAZ survey for PDO. The system was used to migrate one million vibrated points (around 10 billion traces) and was able to generate a real-time field PSTM cube as the seismic shots were recorded. The intermediate PSTM cubes were available in the field for instantaneous quality control. Daily reports including seismic data were sent to the end users (i.e., client, processing center). Immediately after the last recorded VP, the complete PSTM volume was ready to be delivered.

We present how to create realistic geology conformal anisotropic velocity models and reduce depth misties in standard tomographic and high-resolution FWI depth velocity modelling. We assume that localized variations in both velocity and anisotropy are caused by changes in the lithology and we use well information to establish anisotropy/velocity correlation for imaging velocity models.

A conventional CMP based COV binning will create footprint and migration noise for acquisitions where sources and receivers are at different depth levels and/or PS waves are imaged. The OVT muting & weighting technique is a way to overcome this problem. The OVT muting and weighting technique is a way to bin acquired seismic data in such a way that a uniform, or near uniform, illumination is obtained at all depth levels in the model beneath a certain given shallow depth level. The basic idea is to adjust the number of traces in a OVT gather and create a mute based on the depth- and offset dependent CMP-CRP difference computed by ray tracing. This will improve the CRP coverage considerably. This is done on pre-migration data and will create gathers that can be migrated by e.g. Kirchhoff migration. The method can be used for any acquisition technique but will be especially powerful for Ocean Bottom Cable (OBC) or Ocean Bottom Nodes (OBN) acquisitions. It can be used in both Kirchhoff time and depth migration.

The seismic monitoring solution presented here is a permanently buried, fully automatic, and continuous seismic acquisition and processing system. It ensures remarkably repeatable daily seismic. Our specific calendar oriented 4D processing flow is described and applied on a monitoring system installed for Shell on their Peace River project to provide daily monitoring of a heavy oil production pad. The main observation is that 4D attributes vary a lot even when looking at very short calendar periods. This continuous monitoring information gives significant insights into reservoir activities and offers new opportunities to better understand the short term dynamics of the reservoir.