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WAZ’s sparse spatial sampling tends to limit our ability to push for shallow higher resolution image. In the deepwater GOM, there is typically more than one WAZ survey available. However, direct Kirchhoff imaging from multiple data sets suffers poor swing cancellation. To mitigate this problem, we can combine multi-WAZ data and perform interpolation prior to Kirchhoff. Interpolation reduces migration swings but is often not perfect for complex structures and smears details. We propose to use preconditioned least-squares (LS) Kirchhoff to obtain a higher resolution image that can simultaneously benefit from dual-WAZ data sets and overcome the limitation of coarse sampling.

The world-class oil and gas fields of the Gippsland Basin, with original recoverable reserves of more than four billion barrels of oil and around ten trillion cubic feet of gas, were discovered following a 1962 2D seismic survey. Despite considerable exploration, it has long been known that unresolved seismic depth imaging issues have had a significant impact on data quality. As a consequence, the province probably has unrealised exploration potential, particularly in the deeper stratigraphic section. The basin-wide Gippsland ReGeneration reprocessing project by CGG has changed the paradigm and the basin is now seen as rejuvenated, with new exploration opportunities and significant upside potential.

Extended seismic bandwidths provided by broadband acquisitions (BroadSeis), improved illumination from wide-azimuth (WAZ) configurations and high spatial resolution made possible by dense acquisition techniques are all new technologies producing visually compelling imaging and reservoir results. In addition, application of the latest reservoir characterization tools and workflows on these data are bringing greater insight into the inner workings of petroleum reservoirs.

In this paper, we propose an SVD-based (singular value decomposition) shear noise attenuation method that relies on P to drive the algorithm allowing a good signal preservation on Z. Using a fast SVD kernel, this method is suitable for large datasets. We demonstrate the effectiveness of the proposed method on a dense wide azimuth 3D OBS shallow water acquisition involving 56,000 4-component nodes. The results prove the efficiency of the proposed method in removing shear noise with no damage to the signal.

This article reviews the status of hydrocarbon exploration and level of geological understanding in the Durban and Zululand Basins offshore South Africa and it provides clues and new ideas from seismic interpretation and observations of the latest CGG multi-client 2D shot in the area in 2014.

DENVER–The economics of unconventional plays can be improved by placing horizontal wellbores to target facies with the most favorable reservoir and geomechanical properties. Recognizing that, an integrated multidisciplinary approach was developed to reduce economic risk, facilitate improved and faster decision making, and enable more efficient and effective well placement in a tight, stratigraphically complex Upper Cretaceous Sandstone in the Powder River Basin. The subsurface environment was known to exhibit significant variations in lithofacies and reservoir properties, both laterally and vertically. The objective was to provide an accurate and synergized understanding of interwell reservoir characteristics, quantitatively honoring all input geoscience data and verifying through blind well testing. That goal was achieved by utilizing geostatistical inversion to predict lithofacies and reservoir rock/geomechanical properties that honored data from multiple disciplines.

An integrated geological and petrophysical workflow was used to evaluate the Jurassic shale plays in southern England. It illustrates how sedimentological and electrofacies interpretations were integrated with QEMSCAN data to significantly improve petrophysical interpretations and TOC estimates from logs using the CARBOLOG method. Reservoir quality risk maps were based on the sedimentological facies and log-derived elastic properties. Additionally, source quality and maturity were combined to create generation risk maps. The risk for ground water contamination was evaluated and was combined with the reservoir and generation risk maps to create common risk segment maps and identify the "sweet spots".

A quantitative interpretation was carried out in order to improve geological model and de-risk the prospect in the next exploration drilling campaign. Recently drilled exploration wells based on conventional seismic interpretation drilled through channel levee instead of the targeted channel core. Vertical resolution, reservoir quality, distribution and continuity of the channel feature are the main risks. A geostatistical inversion guided by rock physics modeling and deterministic inversion has been conducted to improve resolution, analyze the rock character and deliver probabilistic reservoir properties analysis as part of risk assessment. The results show that this technique improves the mapping of channel features associated with porosity and volume of clay distribution in comparison to the deterministic inversion or conventional seismic interpretation.

Structural information in seismic images is critical for reservoir delineation, reserve estimation and well planning, but is also uncertain by nature. A cause for this is uncertainty in migration model estimated by tomography that straightforwardly affects position of migrated events, both laterally and vertically. We present a method that accounts for uncertainties in subsurface velocity model estimated by tomography, and translate them into the migrated domain. The method comes with QCs for validating computed attributes before integration with other downstream or interpretative information. The method is then applied to a North Sea area covered by multi-survey data.