Least-Squares Migration: Status and Opportunities
Author: Andrew Long
Industry Insights - 5 December 2019
Least-Squares Migration (LSM) treats seismic imaging as an inverse problem, and can be implemented in a diverse range of ways. The common elements are that the output aims to provide an improved Pre-Stack Depth Migration (PSDM), and the velocity model is not updated during the process. When implemented using finite difference operators in an iterative workflow, LSM can be extended to imaging the full seismic wavefield. In addition to improving the amplitude and spatial wavenumber content of seismic images, LSM is now being explored as a solution to compensate for different acquisition geometries and/or shooting directions in 4D projects, or as a possible solution to deliberately reduce the acquisition cost and effort.
Optimizing performance of data processing
Author: Samuel Brown, Tony Martin
First Break - 1 December 2019
The authors describe the process of optimizing data throughput, to reduce turnaround and enable both full automation and interactivity of geophysical tasks in an architecture agnostic environment.
Application-Specific Integrated Circuits and Machine Learning
Author: Andrew Long
Industry Insights - 11 November 2019
An example of seismic data image processing of a real marine seismic dataset is used to demonstrate that Machine Learning has a future for seismic processing, but it also shows that huge training efforts are required for application to even modest input data sizes. As the applications of Machine Learning and Deep Neural Networks (DNNs) extend to ever-increasingly large and complex problems, the computational overheads will correspondingly become significant. Application-Specific Integrated Circuits will expectably become more common to address the vast computational challenges to training DNNs with modern 3D seismic data volumes, and will represent a new class of supercomputer with hundreds of PFLOPS of computing capacity available to solve each problem.
Redefining marine towed-streamer acquisition
Author: Martin Widmaier, David O’Dowd, Carine Roalkvam
First Break - 1 November 2019
The authors describe novel marine acquisition solutions addressing the need for accurate velocity models, high-resolution imaging, and reliable AVO.
Extending Exploration Potential to Western Côte d’Ivoire
Author: William Powell, Avril Burrell, Ibrahima Diaby, Marcelle Gauly
GeoExpro - 1 October 2019
Offshore Côte d’Ivoire is a well-established petroleum province, particularly in the eastern areas. Exploration is now moving into the more frontier region of the western Côte d’Ivoire Basin. To support these efforts PGS, in partnership with Petroci and Direction Générale des Hydrocarbures, has created a fully matched and merged contiguous dataset comprising full stack GeoStreamer 3D, conventional 3D and accompanying 2D across 23 000 sq. km offshore Côte d’Ivoire. The PGS Côte d’Ivoire MegaSurvey now allows exploration and detailed regional evaluation for the first time, allowing plays to be effectively developed and risked.
Introducing the X factor
Author: Halfdan Carstens
GEO - 1 October 2019
With the introduction of GeoStreamer X, PGS challenges ocean bottom surveying with rapid turnaround time and substantially lower cost.
Rejuvenated Seismic Data Available to Boost Exploration in the Flex Trend
E&P Daily News - 18 September 2019
Dataset improves knowledge in GoM subsalt.
Getting Closer to the Reservoir with Rock Physics Integration
E&P Daily News - 17 September 2019
Recent acquisition adds capabilities and data atlases to company’s portfolio.
Marine Vibrator: Source Wavefield Modeling
Author: Sander Losnedahl, Okwudili Orji, Walter Söllner
SEG - 15 September 2019
Traditional marine seismic sources are facing increasingly strict regulation due to their non-negligible environmental foot print. However, marine vibrators are easy to control, are
more efficient and have lower environmental foot print. Here we demonstrate source wavefield modeling for marine vibrators, discuss the source signature requirements and
important processing and imaging steps.
Marine vibrator source: Modular projector system
Author: Okwudili Orji, Mattias Oscarsson, Walter Söllner, ØysteinTrætten
SEG - 15 September 2019
There is a desire by the marine geophysical industry for a seismic source with a low environmental footprint. Received sound pressure level (SPL) and sound exposure level (SEL) can restrict how seismic surveys can be conducted in sensitive areas.
To address this desire, we have developed a broadband nonimpulsive source based on the concept of modular transducer elements. The source has a controlled output that can emit
arbitrary signals, enables flexible source geometries, and can produce ultra-low frequency content that facilitates robust full waveform inversion.
Sea trials and testing indicate that the developed source will meet the challenging output demands and exhibit the necessary robustness to be a viable seismic source for the
future. Large scale testing is planned in 2019.