GR5 Gas Pipeline

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Project Name : Conceptual design and FEED of the GR5 Gas Pipeline

Country : Algeria

Project Location Within Country : Gas pipeline in South Western Sahara, crossing the Grand Erg Occidental (Sand Dunes) running from Aoulef (near Reggane) to Hassi R’Mel

Name of the Client : SONATRACH – TRC (Pipeline Transmission Division)

Start Date : August 2009

Completion Date : July 2011

 

Project description

The GR5 is a new 48" gas transmission system intended to collect the gas to be produced by 9 fields in the South West of Hassi R’Mel. The pipeline route crosses desertic areas, the Aoulet plain, Tademait Plateau, a vast sand dunes area ‘Grand Erg Occidental’, and then Hamada areas up to Hassi R’Mel.

The GR5 transmission system includes a 760 km pipeline 48’’, one intermediary compression station, a final compression station and injection stations at tie-inpoints with branch transporting gas from the field CPFs. A 320 km 48’’ loop will be installed in phase 1 and will be further expanded in the final development phase.

Each compression station is equipped with 3 x 28 MW ISO gas turbine centrifugal compressor sets.

 

Scope of Work

Pre-FEED:

  • Data collection: environmental, climatic, landownership, …
  • Route study:

     

    • ‚ÄčIdentification of a constructible route within a 5-km wide corridor
    • Setting up a Geographical Information System (ArcGIS)
    • Acquisition and analysis of satellite imagery with different resolutions and bands.
    • Geological/geotechnical interpretation, terrain evaluation and sand dune migration study
    • Incorporation of Numerical Terrain Model
    • Site surveys on some sections of the route: validation of NTM, assessment of geotechnical risks
  • Hydraulic study of the GR5 transmission system development phases and techno-economic optimisation
  • Constructability study pipeline and stations
  • Conceptual design of the transmission system: design philosophies, evaluation of possible compression configuration, recommendations.

FEED (Front End Engineering Design) to provide all technical documents to prepare EPC tender documents

  • Detailed route studies:

     

    • ‚ÄčTopographical survey by airborne LIDAR and aerial photography
    • Preparation of alignment sheets 1/10,000 and special crossing drawings
  • Detailed hydraulic study
  • Engineering design of pipeline and stations (2 compression stations, 6 injection stations (with metering)
  • Environmental Impact Study
  • Risks and danger study for pipeline and stations. HAZID – HAZOP review
  • Geotechnical surveys: seismic refraction, resistivity measurements, penetrometer tests and borings
  • Budget cost estimate
  • Preliminary implementation schedule
  • Preparation of the documents for the application for construction permit.