Offshore Facilities

  • 1Gas is produced by using twin four-slot templates for each of three drilling centers
  • 2

    Produced gas is transported by the flexible production risers (vertical pipes) from a template to the Floater

    Outer riser
    diameter is ≈ 36 cm

  • 3Mid-water arches support risers before hydrocarbons are supplied to the Fl oater
  • 4Gas processing and gas and condensate separation are performed on board the Floating Production Unit
  • 5

    From the Floater processed gas is exported by flexible risers

    Riser outer
    diameter is ≈ 36 cm

  • 6Risers are connected to pipelines by means of special device
  • 7

    Two pipelines carry gas to onshore facilities

    Gas will be produced from the self-propelled process-oriented Floater by utilizing unique technology

    Outer diameter
    of each pipe is ≈ 92 cm 

    For dedicated communication between the FPU and Operation Support Area in Teriberka,a Fibre Optical Cable (FOC) will be installed

Offshore facilities scale

  • 320 m

    As long as 3 football fields

  • Depth
    340 m

    Shtokman
    field

  • 324 m

    Eiffel
    Tower

  • 138.75 m

    Great
    Pyramid of Giza

  • 540.1 m

    Ostankino
    Tower

Technical challenges to develop and operate Offshore Facilities come from:

  • High design capacities to be complied with;
  • Remote offshore location (550km from mainland) without any nearby development;
  • Harsh conditions due to the Artic environment (low temperatures, ice, icebergs, snow, fog, polar nights, etc.) for development and operation, implying weather season limitations, required «winterization», complex logistics, difficulties in Emergency Evacuation and Rescue support;
  • Environmentally sensitive ecosystem that shall be protected;
  • Lack of Offshore experience and dedicated technical regulation in the Russian Federation.

Following comprehensive conceptual and engineering studies (FEED), surveys data and risk assessments, the general offshore facilities development scheme that has been selected is based on the Subsea Production System (SPS) tied-back through  system of umbilicals, flowlines and risers (UFR) to the disconnectable, ice-resistant Floating Production Unit (FPU — ship shape) hosting gas processing, gas compression, living quarter, power generation and all other utilities required to operate. Gas transport from the process vessel to the LNG onshore plant and onshore pipelines will be ensured through two 550 km long 36″ trunklines.

Drilling

Wells are planned to be drilled and completed using two drilling/completion rigs MODU (Mobile Offshore Drilling Unit). 16 wells planned with a maximum angle of 80 degrees, a maximum length of 3400m and a maximum depth of 2200m. The expected average time to be spent on each well is 100 days, including completion.

SPS (Subsea Production System)

The subsea production system will consist of Xmas trees, each linked via a well jumper to a template gathering the gas produced from 4 wells (maximum). Six 4-slot templates are planned to be developed over 3 drilling centers.

UFR (Umbilicals, Flowlines and Risers)

The Subsea Production Templates are linked to the FPU through six flowlines of 16″ diameter, three Infield Riser Bases (IRB) and six rough bore flexible risers of 14’’ diameter; eighteen interconnecting spools are completing the system. The export part consists in four smooth bore flexible of 14’’ diameter linking the FPU to the two 36’’ export pipelines through specific subsea devices (TRB – Trunkline Riser Base and PLEMs – Pipe Line End Manifold) interconnected with four rigid connecting spools. Umbilicals dedicated to each production and export system enable to control the various subsea equipments from the FPU.

FPU (Floating Production Unit)

The FPU that is planned to be built for Shtokman Phase I is one of the largest in the world.

After the concept had been selected, it was decided, in order to optimize competition, to launch a compensated call for tenders (CCFT) for FEED design with the participation of two big engineering consortiums: Aker/Technip/SBM and Saipem/Samsung with Sofec as main subcontractor for Turret and MRB (Mooring Riser Buoy). At the end of Tendering phase, the first consortium has been reconfigured as Technip/Daewoo with SBM as main subcontractor for Turret and MRB while the second consortium kept its initial configuration.

As for the method of Offshore processing, a simple and straightforward process was selected to have a dewatered two-phase flow in the pipelines. The basic process consists of gas-condensate-water separation, a dehydration unit, gas compression unit, condensate pumping, and manifolding to inject the gas and dehydrated condensate into the pipelines.

Subsea pipelines

Gas and condensate will be transported in two-phase flow from the FPU to shore via two 36″ pipelines 550 km long. The pipelines will be locally trenched after their installation, in order to optimize the construction schedule, reduce the cost and improve the robustness to Flow Assurance.

Fibre Optical Cable

A dual fibre optical cable will be used for communication between the FPU and the control centre in Teriberka.