p-cable: sismica marina 3d ad altissima risoluzione
TRANSCRIPT
Welcome to P-Cable News!
P-Cable News
P: (408) 954-0522 • E: [email protected] • www.geometricspcable.com • 2190 Fortune Drive • San Jose, CA 95131 U.S.A.
Inside NCS Subsea Completes First Phase of SAFE-BAND Geohaz-ard Survey 2 High-resolution Stratigraphy 3 Diablo Canyon Seismic Assess-ment 4
No Squinting Required 4
Need
This is the first volume of a quarterly newsletter featur-ing the Geometrics P-CableTM UHR3D system. You are receiv-ing this newsletter because you have contacted us in the past regarding our marine seismic systems, or have expressed a specific interest in the P-Cable. If this newslet-ter was forwarded to you by a colleague, and you would like to be added to our mailing list, please click here.
We, and most who have used it, believe the P-Cable is the future of high-resolution seis-mic. The resolving power of
the P-Cable truly represents a quantum leap over current high-resolution techniques, and as exploration chal-lenges continue to mount, it is finding its niche. After many years of development, with valuable assistance from research groups like Tromsø University and IFM Geomar, it is now gaining momentum in industry, and we hope you find this pub-lication useful in keeping abreast of developments. Please direct any comments you might have, positive or negative, to [email protected].
Since this is our first news-letter, below are some links to background information you might be interested in. Also, you will find the P-Cable website to be full of useful information, includ-ing numerous examples of data acquired with the system.
What is the P-Cable?
History of the P-Cable
Recent Technology En-hancements
Frequently Asked Questions
Sample Data
P-Cable? What’s that?
February 1, 2015Volume 1
Conventional 3D seismic data over UHR3D P-Cable data. Conventional data courtesy TGS. P-Cable data courtesy Tullow Oil and WGP Survey.
P: (408) 954-0522 • E: [email protected] • www.geometricspcable.com • 2190 Fortune Drive • San Jose, CA 95131
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NCS Subsea Completes First Phase of SAFE-BAND Geohazard Survey
The applicability of UHR3D seismic methods in the deep-water GoM was regarded with cautious op-timism by industry leaders. Specifically, what penetra-tion can be achieved with a relatively small source and short offsets? Can steep dips be imaged? What sort of bandwidth can be
recovered? What resolution can be expected? These ques-tions are roundly answered with the data collected during the first SAFE-BAND phase. Penetrations in excess of 2 seconds TWT below seabed were achieved. Steep dips in excess of 16° were imaged, and dominant frequencies between 78 and 100 Hz were
NCS Subsea, in partnership with Spec Partners and Geotrace, recently wrapped up the first phase of their SAFE-BAND geohazard program in the Gulf of Mexico. Targeting the deep-water trend of Green Canyon, Ewing Bank, Atwater Valley, Mississippi Canyon and Viosca Knoll, SAFE-BAND is the first multi-client geohazard survey con-ducted in the GoM. It is also the largest-scale UHR3D survey ever conducted in the GoM.
recovered. The vertical resolution of these data in the upper half-second below seabed is as high as 1.5 meters, and the horizon-tal resolution is consistent with the natural acquisition bin size of 3.125 m x 6.25 m. Numerous aspects of the subsurface geology, such as fluid expulsion features, fine-
scale faults and narrow gas anomalies were imaged. Also, exquisitely-resolved aspects of the seafloor geomorphology confirm that the bathymetric detail achievable with P-Cable data rivals that of data col-lected with ship-mounted multibeam echosounders. As more examples of these
Profile from preliminary 3D cube.
Close-up view illustrating the vertical and horizontal resolution of the top of a mass-transport deposit.
P: (408) 954-0522 • E: [email protected] • www.geometricspcable.com • 2190 Fortune Drive • San Jose, CA 95131
P-Cable News Page 3 of 4
High-resolution StratigraphyThe potential for strati-graphic analysis from seis-mic data is limited by the data resolution. The high vertical and spatial resolu-tion of P-Cable data allows seismic stratigraphic map-ping and analysis where conventional 3D seismic only provides an outline of the investigated features. The potential for improved stratigraphic understand-ing by utilization of UHR3D data is illustrated by P-Cable data from the Bjarmeland Platform acquired in 2012. A Lower Cretaceous pro-gradational event is recog-nized over large parts of the Barents Sea. It is char-acterized by south-dipping
clinoforms sourced from the uplifted northern part of the shelf. P-Cable data provide a better insight into the na-ture of the event as it reveals the internal structure of the clinoforms not imaged in conventional 3D. The data show evidence of sev-eral progradational events separated by shorter periods of relative high water. The in-dividual foreset beds create a down-lap surface to a few laminated horizons situated above the Base Cretaceous Unconformity (BCU). This feature is also beyond the resolution of conventional 3D seismic, but it is impor-tant for development of a complete understanding of
Inline slice from P-Cable 3D cube from the Bjarmeland Platform area, Barents Sea. The data show deltaic progradations downlapping onto thin horizons overlying the Base Cretaceous Uncomformity. Data courtesy of WGP Survey and TGS-NOPEC.
data become available in the public domain, we are confident that UHR3D methods will become the standard for geohaz-ard identification and delineation in the GoM.
that the uppermost Jurassic Hekkingen Formation represents syn-rift deposits, as the thickness of this forma-tion clearly varies over flattened fault blocks.
the depositional history in the region.
The high vertical resolution can also contribute to the understanding of the struc-tural evolution. Flattening on the BCU shows evidence
NCS Subsea Completes First Phase of SAFE-BAND Geohazard Survey (cont.)
Close-up view illustrating the vertical and horizontal resolution of gas anomalies and faulting.
(Near) seafloor pick illustrating the resolution of seafloor geomorphology.
P: (408) 954-0522 • E: [email protected] • www.geometricspcable.com • 2190 Fortune Drive • San Jose, CA 95131
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An extensive UHR3D seismic survey was undertaken in 2011 and 2012 for Pacific Gas and Electric Company (PG&E) to better define the Shoreline fault. Although the original idea was to determine offsets by imag-ing offset buried channels, the faults are difficult to miss in the plan view of the bedrock reflection, shown at right, with or without the stream channels. Con-ducted by Fugro West and Subsea Systems, with array positioning provided by
NCS Subsea, this was the first commercial use of the P-Cable, and probably the highest-resolution 3D seis-mic survey ever conducted. A triple-plate boomer was used for a source, and the array consisted of fourteen 50m GeoEels spaced at 6.25m intervals. Bin size was 3.125m x 3.125m; in-line fold was 8. Because this survey was conducted in California State waters, this was a sun-up to sun-down operation, entailing a full deployment and retrieval every day. Even
Diablo Canyon Seismic Assessment
No Squinting RequiredA joint venture multi-client project between WGP Survey and TGS-NOPEC acquired over 500 km2 of ultra- high-resolution 3D seismic data with the P-Cable system. The focus of the project was seismic im-aging of shallow oil and gas in the Hoop Fault Complex (HFC) area in the Norwe-gian Barents Sea. Clari-FiTM
processing has for the first time been performed on P-Cable data, resulting in even better imaging of the subsurface. In the HFC area the new data provides an important contribution to the Holy Grail in seismic hydrocarbon exploration – direct detection of hydro-carbon indicators.During the summer, the Hoop area was subject to an extensive drilling campaign, with several wells drilling different prospects defined by conventional 2D/3D seis-
mic data and EM data. All of the three major prospects drilled were classified as dry; only minor technical discoveries were made. This clearly demonstrates the complexity of the area and emphasizes the benefit of high-resolution data to ob-tain a better understanding of the geology.
Most petroleum discoveries in the Barents Sea have res-ervoir in the Upper Jurassic Stø Formation. In large parts of the Barents Sea this in-terval is located at the ideal target depth for the P-Cable system due to Cenozoic up-lift and subsequent erosion. The new multi-client data clearly demonstrate the ef-ficacy of P-Cable seismic for imaging direct hydrocarbon indicators in this region. The figure shown at the right reveals multiple “flat spots” within the Jurassic
“It looks like a high-resolution air photo.” – Phil Hogan, Fugro
Bedrock time-slice showing stream channels and faults. Data courtesy Pacific Gas & Electric, 2014.
sequence in several adjacent fault blocks. This example (and more to be released soon) clearly shows the added value and de-risking potential of P-Cable data in hydrocarbon exploration. Combined with deeper-pen-
etrating regional data, P-Cable data can be used for better reservoir definition and volume estimation and be a powerful tool in both hydrocarbon exploration and field development.
Data from the Hoop Basin area in the Norwegian Barents Sea showing a “flat spot” in several adjacent fault blocs indicating the presence of hydrocarbons in Jurassic reservoir rock. Data courtesy of WGP Survey and TGS-NOPEC.
with that and in-fill, production averaged 1.25 km2/day at 6.25m sail line spacing. The full report can be found here ; Chapter 3 focuses on the P-Cable work. Selected data can be found in the Sample Data section of the P-Cable website.