EngРусTürk

A Unique Project

TurkStream is a project that advances the technical boundaries of the industry as the first 81 centimeter wide system laid at depths exceeding 2 kilometers.

Designed for maximum safety

Each of the two offshore pipelines of TurkStream is made up of thousands of individual pipe joints of 12 meters in length. The pipes have been made from 39 millimeters of specially designed carbon manganese steel plates so that it can withstand the huge pressure under the sea. Pipes laid in shallow waters closer to the shore have been coated in concrete for added stability and protection against marine activities.

When operational, TurkStream will offer a reliable energy supply for Turkey and Europe by delivering 31.5 billion cubic meters of natural gas annually.

Pipelines are one of the safest, most convenient and most efficient ways to transport natural gas.

Pipes laid in shallow waters were coated with 5–8 centimeters of concrete for additional stability

Concrete
coating

Steel pipe
wall 3.9 сm

External
coating
of three-layer
polypropylene
against
corrosion

Internal
epoxy coating
against friction

Offshore pipe laying

The biggest construction vessel in the world, Pioneering Spirit, carried out the offshore construction of the TurkStream Project.

The pipe joints have been welded to each other and to the main string on board. Each weld was tested and coated for protection before the pipeline string was lowered into the water.

Pioneering Spirit has completed the construction of the two pipelines across the Black Sea over 15 months, adding new sections to the pipe string as it progressed. Operating around the clock, the vessel laid 5 kilometres of pipeline on average each day. In August 2018, it set a world record in the industry by constructing 6.3 kilometers of the pipeline in a single day. Offshore construction in the deep-water section has been completed in November 2018.

After production, the individual pipes were stored in ports on the Black Sea coast.

Production of plates

Plates

Welding

Ultrasound and x-ray

Special Coating

Shipment to the port

Shipment to the storage

Intermediate storage

Shipment to the vessel

Special vessel



A new benchmark in the industry

The technical and material specifications of TurkStream are setting new benchmarks for the gas transport industry. The TurkStream Offshore Gas pipeline is the largest system ever to be laid at depths as low as 2,200 metres.

Underwater Visual Inspection

Using a Remotely Operated Vehicle (ROV), it is possible to film in the deep seas to investigate objects in detail and perform a visual inspection of the route, the pipeline and other structures that are installed. For its main activities, the ROV carries other instruments as well, such as sonars, magnetometers, pipe-trackers, or manipulators.

High-resolution seismic survey

A vessel produces a strong sonic pulse that hits the seabed and propagates under the surface. The seabed reflects a part of the pulse which returns, whilst a part travels through the seabed. Measuring the timing, geometry and the intensity of the returns of the sonic pulse, geophysicists can map the different layers underneath the seabed.

Echo sounding

A multi-beam echo sounder (MBES) emits several acoustic pulses, which hit the seabed or any object that is on the seabed, and are reflected back in different times and geometries, depending on the shape of the object. Hence, a 3D model is formed which shows the seabed topography, the shape and the depth of objects.

Sub-bottom profile (SBP) survey

A transducer emits a sound pulse vertically towards the seafloor, and a receiver records the return of the pulse. This technique helps create an image of the layers of sediment under the seabed. As a mini-seismic tool, the SBP is usually towed closer to the seabed, if not directly mounted on a ROV.

Side scan sonar (SSS) survey

The SSS is used to create an acoustic image of large areas of the adjacent sea floor, by scanning up to 500 meters each side of the equipment in order to investigate any possible obstacles near the route. The sonar uses high frequency pulses, and can be towed directly from the vessel, or installed on a ROV. By analyzing the acoustic shadow, the time of the pulse, the intensity and other acoustic factors, the dimensions of objects, obstacles or seabed features can be determined.

Seabed samples

Using a range of different techniques, samples are taken from the seabed at different depths, and analyzed in a laboratory to determine the environmental, geological or geotechnical properties. The result of these analyses, studied in correlation with other geophysical properties of the seabed, are used to produce a geological map of the sub-seabed, and to ascertain if the seabed is suitable for pipeline laying.

Maximum Depth, m
Offshore length, km
100
500
1000
70
Franpipe in the North Sea, ø 110 cm
210
Nord Stream in the Baltic Sea, ø 122 cm
360
Langeled in the North Sea, ø 112 cm
400
Maghreb-Europe pipeline in the Mediterranean Sea, ø 56 cm
610
Trans-Mediaterranean Pipeline in the Mediaterranean Sea, ø 59 cm
1150
Greenstream in the Mediterranean, ø 81 cm
2150
Blue Stream in the Black Sea, ø 61 cm
2160
Medgaz in the Mediterranean, ø 61 cm
2200
TurkStream Offshore Pipeline in the Black Sea, ø 81 cm
2530
Perdido Norte in the Gulf of Mexico, ø 46 cm

Exploring the Deep Seas

With the expertise of specialized engineers, TurkStream used advanced pipeline design and technology to create a pipeline that will safely withstand high pressure. The system has been divided across 2 separate gas pipelines, welded together from 12-metre pipe segments with a diameter of 81 centimetres each. Using the latest techniques in steel production and high-precision pipe manufacturing, engineers were able to design strong pipes with a wall thickness of 39mm. With over 150,000 pipes, the entire system is not only strong enough to withstand the high external water pressure, but also resists an internal design pressure of 300 bar, thus enabling the safe and reliable transport of large volumes of natural gas.

With these unique design characteristics, TurkStream is a project that has set new standards in offshore gas transportation.

Ensuring the safety of the pipeline

The pipe will be periodically inspected from the inside, by running pipeline inspection gauges, or PIGs, through it. The PIGs enter the pipeline at the Russian landfall facilities and are propelled by the gas flow towards the landfall facilities near Kiyikoy, where they are removed via special PIG receivers.

Critical sections of the pipeline route, including slopes, trenches, anomalous seabed areas, and the continental shelf break, will be surveyed more frequently: first annually, and then as often as necessary based on monitoring results.

Read next

Benefits

Gazprom has been supplying gas to Turkey since the 1980s.