Severstal keeps focus on Offshore Projects

September 15, 2021, posted by savannahweeda

Author of the Article:

Konstantin Barabash
Head of the Technical Sales Department for Export markets,
Sales and Business Development in Energy
PAO Severstal

Large-diameter pipes for oil and gas transportation

Today, onshore oil and gas fields are in depletion phase, and one of the most promising ways to meet this current challenge for energy companies is to focus on offshore projects to enable further development of the production of oil and gas.

When it comes to offshore field development, technically advanced and highly reliable equipment is in demand, including the construction of new ships and tanker fleets, drilling platforms and pipelines for hydrocarbons transportation.

Offshore pipelines are critical elements of the subsea transportation system for delivery of carbon products from rigs to consumers. Materials for the construction of this kind of pipelines shall meet specific operating requirements. In fact, these ones call for such technical features that enable pipes to withstand extremely low and high temperatures and high pressure. As so, increased strength, sufficient impact toughness and corrosion resistance are among the main technical features required for such pipes.

PJSC Severstal, one of the world`s leading steel and steel-related mining companies, offers Energy customers longitudinally welded large diameter pipes (LSAW pipes) in use for oil and gas transportation via onshore and offshore line pipelines. The production asset of the company Izhora Pipe Mill has been continuously developing the technology throughout the entire production cycle, from the production of raw materials to finished pipes, finding solutions tailored to specific needs within the implementation of projects.

One of the recent projects that the company is taking part is the Yuzhno-Kirinskoye field in Russia, carried out as a part of the Sakhalin III project by Gazprom.

The Yuzhno-Kirinskoye field was discovered by Gazprom in 2010. Its reserves amount to 711.2 billion cubic meters of gas, 111.5 million tons of gas condensate (recoverable), and 4.1 million tons of oil (recoverable). The expected output of the field is about 21 billion cubic meters of gas per year.

For the development of the Yuzhno-Kirinskoye field, Severstal managed to offer the best technical solution to meet the climatic conditions of the region and the practical tasks: for the offshore gas pipeline, pipes with a diameter of 508 mm (20”) and a wall thickness of 27 mm have been supplied to the customer. Such combination of diameter and thickness enables to reduce metal consumption by 1.5 % compared to similar solutions, which positively affects the cost efficiency of the project.

Severstal has also taken part as a pipe manufacturer in a number of other key projects: Bovanenkovo – Ukhta, Bovanenkovo – Ukhta 2 and Turkstream.

The Bovanenkovo – Ukhta project provides the construction of gas pipeline for the transportation of natural gas from the Yamal Peninsula into Russia’s Unified Gas Supply System, being one of the most challenging projects in gas transportation worldwide. The company has supplied pipe products for the construction of the water crossing and onshore sections of the line gas pipelines Bovanenkovo – Ukhta and Bovanenkovo – Ukhta 2.

Severstal has successfully set up the production of DNV-OS-F101 large-diameter steel pipes for the Turkstream gas pipeline project in 2014.The offshore part of the gas system consists of two lines running along the bottom of the Black Sea.

The deepness of the pipeline has created new challenges for production.

For example, a special project requirement was 4 mm out-of-roundness along the pipe body to reduce the water pressure on the pipeline. Also, to improve the mechanical properties of pipes and the reliability of the pipeline, a special low-temperature tempering was carried out on the coating line with strict requirements for the temperature and time of heat treatment.

In order to fulfill all requirements modernization of the equipment was carried out: an additional pipe-forming unit and automatic geometry measurement unit with a measurement accuracy of up to 0.001 mm were purchased. The measurement unit provides continuous registration and control of measurements.

It took less than a year from the appearance of the project requirements to the successful manufacture of pre-qualification pipes.

Overcoming all challenges gave Severstal an unique experience and excellent results. The company has supplied 260 thousand tons of SAWL DNV 450 SFDU pipes with a diameter of 813 mm and a thickness of 39 mm, a length of 12 m with an external polypropylene coating and a concrete weighting coating.

Due to the high complexity and responsibility of the offshore technology, Severstal has been designing innovative pipes with the main goal to reduce construction and operating costs of line gas pipelines, keeping the focus on high reliability for pipelines operation within the implementation of technically challenging projects.