Sub-bottom Profiling (Geophysical) and Geotechnical Sampling
The planned NordLink submarine cable connection is a power transmission link between Norway and Germany. The length of the cable route is about 518 km with water depth down to about 410 m. The deepest part is in Fedafjorden and the water depth along most of the route in Danish and German waters is less than 40 m. The last 30 km towards Germany is shallower than 11 m, and some mudflats that are dry during low tide are crossed.
The Norwegian Transmission System Operator Statnett SF will own 50 percent of the project. The other 50 percent will be owned by DC Nordseekabel GmbH & Co. KG (NOKA), consisting of the shareholders TenneT TSO GmbH (German Transmission System Operator) (TenneT), and the promotional bank of the Federal Republic of Germany and the German Federal States - Kreditanstalt für Wiederaufbau (KfW). The high voltage direct current (HVDC) interconnector will connect the electricity systems of Germany and Norway and provide access to a combined larger market for planned renewable energy. The integration of the Norwegian and German electricity markets will ensure improved security of supply, increase market efficiency, and thus contribute to economic value in both countries.
The main objectives of this survey is to verify and expand upon already existing survey and geotechnical data in order to gain better knowledge of the seabed soil conditions along parts of NordLink route. Important sub objectives include, but are not limited to localization of clay and peat pockets and localization of soil with high thermal resistivity properties.
The scope of work:
The survey shall be performed by one or two survey vessels capable of operating from 5 m (MSL) water depth in Germany, offshore at any point along the Nord.Link route and in the narrow fjords of Norway. The main objective of the survey is to identify clay and peat pockets and identify areas with high thermal resistivity. Other tasks may be scouting for route alternatives, cable and pipeline detection etc. Sub-bottom profiling (SBP) survey: The SBP equipment shall be INNOMAR SES2000 (or equivalent) and be chosen based on local soil conditions. Emphasis is to achieve high resolution data of the uppermost 10 meters of seabed. The tenderer shall describe
suitability of the chosen SBP equipment based on knowledge of the soil conditions in the area of operation and experience in similar expected conditions. The tenderer shall demonstrate that the vessel is suitable for the SBP equipment and that sufficient expertise is available for operating this equipment. Geotechnical sampling:
Three different geotechnical sampling methods shall be utilized at each chosen location. The locations will be selected onboard based on the interpretation of the sub-bottom profiling survey results. An estimate of the number of sample locations and the specifications for the lab testing to be performed will be provided in the ITT document
Vibrocores:
Geotechnical samples shall be taken with a vibrocorer along the route between the two end positions.
Equipment must be capable of obtaining 5 m core lengths. The samples must be processed in laboratories on the vessels or in onshore labs after performance of the survey. CPT's:
Cone Penetrating Testing shall be taken along the route between the two end positions. These CPT's shall have the capability to penetrate the soil up to 5 meter depth and be able to take in-situ thermal resistivity readings.
Gravity cores:
Geotechnical samples shall be taken with a gravity corer along the route between the two end positions.
Equipment must be capable of obtaining 5 m core lengths. The samples must be processed in laboratories on the vessels or in onshore labs after performance of the survey.
Other tasks:
For scouting for route alternatives, cable and pipeline detection etc., the spread shall include a hull mounted multibeam echosounder, (MBE) and a ROV (optionally AUV) and/or towfish for surveying with MBE, SBP, sidescan sonar, magnetometer and/or suitable cable/pipeline detectors.
Documentation:
A field report shall be handed over at demobilization and a complete final report with all documentation and results of lab tests shall be delivered 1 month after performance of the survey
Deadline
Die Frist für den Eingang der Angebote war 2014-01-17.
Die Ausschreibung wurde veröffentlicht am 2013-11-25.
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Geschichte der Beschaffung
| Datum |
Dokument |
| 2013-11-25
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Auftragsbekanntmachung
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