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The benefits of CGG technologies and services are regularly featured in the industry press. Find out more by consulting our e-library of published industry articles. Narrow your search by entering at least one search criterion:

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High-frequency acoustic land full-waveform inversion: a case study from the Sultanate of Oman

First Break, January, 2019
Anna Sedova | Gillian Royle | Thibaut Allemand | Gilles Lambare | Olivier Hermant
©2019 EAGE

In this paper we demonstrate the ability of acoustic land FWI to recover a high-resolution velocity model using reflected waves in addition to diving waves and inverting up to 13 Hz.

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Rock-physics-assisted well-tie analysis for structural interpretation and seismic inversion

The Leading Edge, December, 2018
Reza Saberi
©2018 SEG

Well-tie analysis is a starting point for mapping facies and geology observed at well locations onto seismic cubes. This step is very important for any application that uses seismic and well data together, and can secure more accurate results by increasing consistency between seismic and well log data. A high-quality well-tie is normally considered as the art of an interpreter and is usually practiced through stretch and squeeze of the synthetics log. Many factors can affect the quality of a well-tie, and well log quality is one of the more important ones. However, interpreters and geophysicists focus mainly on seismic and wavelet components and assume well logs as hard data. In practice, well logs are susceptible to different types of errors which may not be fully addressed during the petrophysical work. This paper goes into more detail about this issue and suggests rock physics as an efficient tool for repairing well logs to achieve a better-quality well-tie. Furthermore, different examples from various studies are presented to show the importance of improving well logs using an appropriate rock physics model before well-tie analysis.

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Increasing resolution in the North Sea

First Break, December, 2018
Phil Hayes | Luke Twigger | Krzysztof Ubik | Thomas Latter | Chris Purcell | Bingmu Xiao
©2018 EAGE

Below is a case study of the ongoing work on the Monarb and Seagull reprocessing projects in the Central North Sea, with a focus on the use of legacy near field hydrophone recordings, 3D recursive MWD, wave equation deconvolution and AVO QC (In particular Vp/Vs and Lambda Rho QC attributes)

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Multi-Sensor Streamer Broadband 4D Acquisition

First Break, November, 2018
Jo Firth | Gordon Poole | Federico Buriola | Steve McDonald | Paul Fallon | Steve Hollingworth | James Cooper
©2018 EAGE

The desire to extend all the benefits of broadband 3D data to 4D time-lapse surveys has been hampered by the requirement for repeatability between successive surveys. The use of deep-towed multi-sensor streamers in time-lapse acquisition creates challenges, as the existing baseline surveys will often have been acquired using a shallow-tow streamer. For optimal 4D repeatability, subsequent monitor acquisitions would traditionally be acquired using the same streamer depth as the earlier surveys. We tested recording monitor data at a deeper streamer depth than the baseline survey using multi-sensor streamers, and then redatumming to simulate data recorded at the shallow streamer depth. Following this trial, we went on to acquire three 4D monitor surveys.

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Measuring gravity gradient in rugged terrain: HeliFalcon survey in Aso-Oguni, Japan

First Break, October, 2018
Tianyou Chen | Mark Dransfield
©2018 EAGE

In this paper, we look at the HeliFalcon AGG survey conducted in the Aso-Oguni area exploring for geothermal fields, examine the technical challenges presented by the rugged terrains, describe some aspects of the data acquisition and processing, and present the survey results.

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