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In this paper, we present the importance of a regional dataset, acquired and processed with the latest seismic imaging technologies to better understand the depositional environments of one of the main hydrocarbon plays in the Northern North Sea – the Upper Jurassic sandstones. Here we use frequency decomposition colour blending (RGB) to identify depositional pathways of Late Jurassic sands, where they can be seen to feed in from the east extending across to the west through deep water canyon systems, largely controlled by fault systems.

Superimposed reservoirs are common in oil and gas production, but they are challenging to monitor with time-lapse seismic imaging. A common seismic attribute used for assessing reservoir evolution during production is the time-shift measurement which is obtained comparing two 3D seismic images. In the case of superimposed reservoirs, computing these time-shifts becomes challenging due to the change at the top reservoir that affects measurements at the lower one. Directly computing the wave propagation velocity variation between the time-lapse seismic data is an alternative solution. These obtained velocities need to reach a sufficiently high frequency to ensure a vertical resolution to correctly separate the reservoirs. On two offshore West-African case-studies, we illustrate how 4D FWI workflow can finely separate superimposed reservoirs, by providing high resolution velocity variations along the monitoring time. The first case study consists of short offset towed streamer acquisition where the challenge of missing low frequency and diving wave penetration is undertaken by a combination of 4D tomography and 4D FWI. For the second case study, long offset node records mean that only the 4D FWI is needed. This time saving allows for prompt delivery of the velocity variation with time without requiring a complex time-lapse processing beforehand.

Yinggehai basin is one of the most important basins of the South China Sea for its mega gas reservoirs and exploration potential. Vintage seismic data generally suffers severely from complex structures, including diapir formed by thermal fluids, strong shallow gas fields, and complex faulting systems. The diapiric structures in particular, commonly present in the region, and have long been an ‘unseen Elephant’, causing much uncertainty in geological interpretation. Reprocessing vintage streamer data has not been sufficient to overcome these imaging challenges so a new OBN dataset was acquired, and the latest processing technologies applied, including visco-acoustic Time-lag FWI (TLFWI), Dynamic Resolution TLFWI (DR-TLFWI), and Diffraction Imaging. With the combined uplifts, the diapir structure is much better imaged, significantly impacting the geological interpretation within this basin.

Ten years ago, CGG launched a project to develop a new concept of marine vibrator (MV) technology. We present our work, concluding with the successful acquisition of a seismic image using an ocean-bottom-node 2D survey

An increasing number of discoveries with high CO2 content offshore Brazil highlight a new exploration risk for the pre-salt play. New seismic data is fundamental to understanding deep geological features to address this risk. CGG’s Nebula-C data set provides images down to 20 km in depth and shows ultra-deep crustal features in high definition. Mapping the Moho and deep-seated faults is essential to understanding possible paths of mantellic CO2 migration to pre-salt reservoirs. A de-risking study was performed using Nebula-C to map where the deep-seated faults connect Moho and the reservoir, and where the lower crust is not offset by faulting, allowing prospect identification with lower risk of CO2 contamination.

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This paper presents a detailed and integrated methodology and case study for building a 3D geological model to characterize a Lower Cretaceous reservoir for a field located offshore Abu Dhabi.

In this paper, we discuss the deblending result of a penta-source marine towed streamer data. The small dithering time renders the cross-talk noise to be semi-coherent in all domains, making this dataset challenging for existing deblending techniques. To tackle this data, we propose a new model-based deblending scheme (MBD) which supplements the previously proposed deblending scheme.

3D elastic modelling was performed to compare two acquisition designs . Blind full processing sequence was applied to ensure unbiased conclusions and final quality. Final quality on stack sections are similar in quality for both flat and highly structured sub-surface. some major advantages of carpet recording shall be mentioned: computation cost savings for feasibility studies, the use of a coherent geophysical unit (one shot point), compared to a cross spread (an aggregate of several different shots) may lead to easier preprocessing sequence, shot points can be migrated independently, and working with shot points allow thus real time imaging, impossible with cross spread design.