Rock Physics: From Basics to the Validation of Advanced Seismic Technology Platforms
Author: Andrew Long
Industry Insights - 28 June 2021
Five short webinars that focus on several aspects of rock physics are now available on-demand at https://www.pgs.com/techbyte. These address fundamental challenges related to the use of rock physics: How can we build robust saturated rock physics models of a heterogeneous earth? How can machine learning and geologically-consistent rock physics modeling workflows reduce exploration uncertainty? How can FWI models augmented by rock-physics transformations overcome missing low frequencies? What low-frequency amplitude and phase issues in broadband seismic data are critical to rock physics estimation workflows? How can rock physics estimation workflows validate new seismic technology platforms in frontier areas with minimal-to-no well control? Throughout the five-part mini-series, emphasis is given to rock physics being the bridge that connects geophysics and geology, and that guides QI efforts. Geologically-consistent rock models can be built that are augmented by FWI models, and FWI models can be reliably transformed into robust elastic low frequency models. With these platforms, various global case studies illustrate how carefully processed multisensor broadband seismic data can therefore be used to predict accurate lithology and fluid properties—even when well control is poor.
GeoStreamer X Delivers Near-field Multi-Azimuth Dataset for Accurate Lead Characterisation, South Viking Graben, Norway
Author: Cyrille Reiser, Eric Mueller
GeoExpro - 10 June 2021
PGS has recently acquired and processed an innovative multi-azimuth multisensor survey in the prolific South Viking Graben, Norway. The dataset delivers reliable attributes for accurate reservoir characterization. This area has provided numerous successes in multiple plays over the past decade and more recently the focus is on potential near-field opportunities.
This quantitative interpretation project examines the various Tertiary to Permian reservoir levels using GeoStreamer X data combined with many wells present in and around the area of interest. For the latter, an interactive rock physics modeling product (PGS rockAVO) has been used, enabling a rapid assessment of the elastic property variation as well as the prestack seismic response to changes in reservoir properties (such as, porosity, saturation and volume of clay).
By integrating this new dataset with regional well information, many of the exploration and near-field exploration challenges can be addressed. The evaluation of reservoirs and trapping styles of existing fields and discoveries is now possible with this unique dataset and additional opportunities can be revealed.
New Shallow Seismic Insights
Author: Andrew Long
Industry Insights - 31 May 2021
We will continue to use high-resolution seismic to understand the subsurface risks and opportunities in marine areas as we transition to renewables and lower carbon energy sources as a complement to fossil fuels. CO2 storage in aquifers must be monitored for shallow seal integrity and offshore wind farms require geotechnical ground models and seismic characterization of the near surface. This article addresses the question of whether we will necessarily require entirely new seismic acquisition solutions, or whether existing methods can be adapted to provide new value and insights.
Towed-streamer seismic using tailored acquisition configurations provide an efficient method of accessing high-resolution datasets for several purposes, and some examples are given below. I also show how full wavefield imaging solutions can high-grade existing seismic data to significantly enhance the resolution and quality of shallow images.
Revealing new opportunities with a cost-effective towed-streamer MAZ solution in the South Viking Graben, Norway
Author: Julien Oukili, Luca Limonta, Martin Bubner, Eric Mueller, Terje Kultom Karlsen
First Break - 4 November 2020
The authors provide a fresh look at a new MAZ streamer concept that challenges existing multi-azimuth solutions, including OBS surveys, as it delivers a higher-quality dataset at a fraction of the cost and reduced environmental impact.
GeoStreamer X Viking Graben Delivers Game Changing Results
Author: Julien Oukili, Eric Mueller, Ruben Janssen
GEO - 1 October 2020
Full integrity PSDM data from the 2019 PGS GEoStreamer X acquisition program in the Lille Prinsen area of the Viking Graben is now available. It delivers on all its promises to provide the highest quality seismic imaging and attributes available today.
GeoStreamer X in the Viking Graben Illuminates Complex Targets
Author: Kai Fløistad, Julien Oukili
GeoExpro - 8 June 2020
To meet the industry demand for improved subsurface insight at a reduced cost and with faster turnaround time than ocean bottom surveys, PGS deployed a pioneering acquisition configuration in the Viking Graben in the autumn of 2019. Three months after the last shot on the GeoStreamer X survey in the Viking Graben, the early-out multi-azimuth (MAZ) PSDM seismic stack was delivered to pre-funders. From an interpreter’s point of view the results are stunning, and what started as a novel concept now provides new insight to geoscience teams in near-field exploration, appraisal and development.
There are many targets in the area, ranging from Eocene sand injectites to fractured basement, and an approach integrating survey design, imaging solutions and quantitative interpretation has enabled a significant improvement in the resolution of these reservoirs. The main imaging challenges are the large shallow channels and massive sand mounds in the Miocene as these introduce shadow zones beneath them. Eocene cemented sand injectites, called V-brights, have anomalously high velocities which historically have been very difficult to estimate. Deeper, a thin, rugose Cretaceous chalk layer causes multiples and dispersion of the seismic energy.
Fast Delivery of GeoStreamer X Multi-Azimuth Data
Author: Julien Oukili, Kai Fløistad
GEO - 1 March 2020
GeoStreamer X represents a faster and more efficient method to improve illumination
of complex targets.
GeoStreamer X Pilot Successful - So What's Next
Author: Martin Widmaier
GEO - 19 December 2019
Completion of the GeoStreamer X pilot survey proves that PGS’ novel marine seismic strategy for upgraded acquisition in any geological regime is practical, efficient and within reach. The first GeoStreamer X data is scheduled before next Easter. Planning has begun for 2020 projects.
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.