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7th Pipeline Technology Conference 2012

Nordstream onshore pipeline projects OPAL & NEL - Extraordinary constructions for river crossings by MT or HDD -

The OPAL pipeline (“Ostsee-Pipeline-Anbindungs-Leitung” – Pipeline Link), and the NEL pipeline (“Nordeuropäische Erdgas-Leitung” – Northern-Europe Natural Gas Pipeline), connect Europe to the major natural gas reserves in Siberia via the Nord- Stream-Pipelines. 55 billion m3/a natural gas are split into 36 billion m3/a (OPAL) and 19 billion m3/a (NEL). The OPAL routs approximately 472 km from north to south till Olbernhau at the Czech border where it is linked to the Gazelle pipeline. After 280 km running pipeline (appr. 25 km in the south of Berlin) the pressure is raised up in a compressor station (driving power 3 x 32 MW). The OPAL is a joint venture of WINGAS and E.ON Ruhrgas with construction leadership by GASCADE Gastransport GmbH (formerly WINGAS Transport GmbH) in total. The NEL carries natural gas over a distance of approximately 435 km to the WINGAS storage facility at Rehden. It is a joint venture of WINGAS, Gasunie, Fluxys and E.ON Ruhrgas. The construction along the federal land -Western and between Heidenau – Rehden is headed by GASCADE Gastransport GmbH. Technical details of the pipelines:

OPAL NEL MOP 100 bar 100 bar DN 1420 mm (56”) 1420 mm (56”) Steel grade L 485 MB L 485 MB Number of single pipes 27.000 pcs 24.900 pcs Mass per single pipe 15 t 15 t

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7th Pipeline Technology Conference 2012

Figure: Track of OPAL (green) and NEL (red/violet) The construction of OPAL started in August 2009, in July 2011 the pipeline was mechanically completed and ready for gas-in. The OPAL is in regular operation since October 2011.

The OPAL was divided into 14 lots each a bit more than 30 km long. The pipeline has been built up by the construction companies PPS/Habau, Ghizzoni, Bonatti and Streicher/Sicim.

The GASCADE part of NEL has been divided into 9 lots and lasts over all 308 km. The length of the lots corresponds to the OPAL. The pipeline is being built by the construction companies PPS/Habau, Streicher and Bonatti. The remaining 127 km of NEL are in leadership of Open Grid Europe.

Both pipelines are containing numerous crossings with existing infrastructure, nature reserves and rivers. The following table shows the crossing details of GASCADE project’s scope.

OPAL NEL Roads / Highways 180 82 Streets 296 240 Railway tracks 10 16 Rivers / rivulets 30 280 Third party (pipe-)lines 417 438 In total 933 1056

These crossings were done by:

OPAL NEL Open 763 948 Pipe pressings 164 102 Micro-tunnels 4 2 HDD 2 4

Figure: Track of the OPAL

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7th Pipeline Technology Conference 2012

Figure: Track of the NEL (red/violet)

The open crossing

The Elbe culvert shows an example for crossing by open construction, built up conventionally. A pipeline spool of approx. 300 m length was prefabricated on the north side of the river. After pressure test, this spool was protected with a 22 cm concrete coating and weighted finally approximately 750 to. On November 19th 2009, the culvert was pulled into the river with a wire rope winch. This crossing project was conducted by the consortium Meister/Streicher on behalf of Streicher/Sicim.

The culvert has been supported by (air) tanks (orange) in order to facilitate the pull-in process. These tanks will be cut off, as soon as the culvert has reached his right location on river bed.

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7th Pipeline Technology Conference 2012

Figure: Culvert at Elbe 5

7th Pipeline Technology Conference 2012

Pipeline Coating by glass fibre reinforced plastic (GRP)

The GRP system consists of a glass fraction higher than 60 % with a vinyl ester type resin and has been applied in shop. All welding joints have been wrapped with the same GRP coating on site in order to get completely protected surfaces.

Independent of what kind of bedding was found all closed crossings of OPAL / NEL have been conducted by pipe ramming with the exception of only a few micro tunnelling and HDD’s respectively.

Therefore the pipes were additionally protected with a special glass fibre reinforced plastic (GRP) coating.

Figure: Pipe ramming of GRP-Pipe

Any Pipes which were faced to pull-in (pull-back) or even press- in have been coated by special GRP, and if needed with additional outer GRP sliding frames.

Figure: GRP-Pipe with sliding frames 6

7th Pipeline Technology Conference 2012

Micro-tunnels by use of reinforced concrete pipes

Due to local and soil conditions the harbour of Lubmin, the river , river Trebel, the -Havel-waterway and the nature reserve Löcknitz have been traversed with a micro tunnel. The pipeline itself has been moved inside in one prefabricated piece (by pull-in) or even welded pipe by pipe. This procedure depended on the area/space requirements per each crossing. In cases were the crossing section did not allow a pull-in of one prefabricated pipeline section (e. g. big/death pits, groundwater level, space limits) the contractor was requested to ensure for sufficient fabrication-/NDE-/coating-resources per single pipe/weld in order to finalize those crossings in time available.

Figure: Pipeline section ready for “move-in” (MT)

Lubmin harbour (OPAL & NEL) 2 x DN 2400, l = 200 m Lemme River Peene (OPAL) DN 2400, l = 950 m Pfeiffer Oder-Havel-waterway (OPAL) DN 2000, l = 180 m Lemme Nature reserve Löcknitz (OPAL) DN 2400, l = 360 m Lemme River Trebel (NEL) DN 2400, l = 1.100 m K-Boringen

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7th Pipeline Technology Conference 2012

Anyhow each MT-crossing itself - including the pipeline section move-in details - is a single case situation and has to be designed and executed carefully together with specialist’s know-how.

Engineering preparations of MT shall take care especially of the start and goal pits. They need to be designed covering all requirements from soil conditions (e. g. ground water level and intensity), static needs, space for drilling machine and concrete sections as well as peripheral systems, pull-in or single weld connections, etc. Also any additional systems to be inserted in MT need to be clarified at the beginning (e. g. cable trays, other (even smaller) lines).

Figure: Micro tunnel starting pit

Horizontal Directional Drillings

Due to local and soil conditions the remaining rivers of OPAL & NEL as listed below have been traversed by HDD. The pipeline itself has been drawn inside in one prefabricated piece (pull-back) in all 6 cases.

Crossing Length Pull-in date River Dahme (OPAL) 930 m November 2010 Oder-Spree-waterway (OPAL) 760 m December 2010 River Schaale (NEL) 700 m September 2011 River Boize (NEL) 650 m October 2011 River Elbe (NEL) 1.080 m November 2011 River Weser (NEL) 720 m December 2011

The crossings Dahme and Oder-Spree-waterway have been built up during the pre- Christmas period 2010. One beating advantage of HDDs is the very short time for completion. It took only two weeks to become ready for pull-in after starting the drilling. 8

7th Pipeline Technology Conference 2012

Although weather conditions were really extreme that time, both crossings have been carried out in shift-works (day and night) in order to reach the crossing project target.

Figure: Drilling being pulled in during winter time.

The 4 HDD-crossings on NEL were incidentally in scope of one and the same construction contractor. Therefore they have been sub-contracted to one special drilling company in order to generate an overall package. In order to optimize those 4 drillings in total they have been built up successively started on river Schaale in September 2011 and completed by river Weser in December 2011.

In contradiction to the relatively bad weather conditions in 2010 that time the works were accompanied by good weather in the whole autumn 2011 till begin of December. The big success of this 4-series can be summarized as follows: Within a 4 months’ timeframe 4 big river crossings have been completed with a total length of roughly 3.200m including pipeline sections inserted. On top of that impressing picture the success will be completed as the Elbe crossing will be the biggest one in Europe up to now by a single length of 1.080 m for 56” pipeline. Congratulations to everybody taking part. 9

7th Pipeline Technology Conference 2012

Figure: Pipeline section with GRP coating and roller supports (HDD)

Equal to all pipe ramming or MT’s the prefabricated pipeline section has been fully coated by GRP including the weld sections. The prefabricated section has been fully (NDE-) tested including single pressure test before pull-back in order to ensure full integrity.