Natural Gas Pipeline from Stefani to PPC Aliveri

Client: Public Gas Corporation of Greece (DEPA) S.A.| Country: Greece| Period: 2008-2011

 

A new High Pressure Natural Gas Transmission Pipeline, with 20’’ diameter and length of approximately 72 km (including an offshore section 13.6 km) has been planned to transport gas from the line valve station, located at the main transmission Pipeline of DESFA at Stefani, to the power plant of Aliveri (Evia, Central Greece). 

After the project implementation, the new pipeline shall provide the following operation options:

 

  • Supply with gas of the power plant of Public Power Corporation (‘’ΔΕΗ’’) at Aliveri
  • Supply with gas of the greater urban area of Chalkida where increased energy demand is predicted in future basis, especially for the commercial and industrial sectors

The Project has been designed and it is already under construction and testing according the requirements of the international code ASME B31.8 "Guide for Pressure Piping Gas Transmission and Distribution Piping Systems".

The project comprises of:

  • A 20" underground and cathodically protected steel pipeline of total length 72 km and design pressure 80 barg
  • Two (2) Scraper Stations
  • Three (3) Line Valve Stations

Scope of Work

The scope of ASPROFOS work includes the Basic design, Environmental Impacts Study, Safety Study, Investigation-Licensing, Geoseismic-Geotechnical Studies and Detailed topographical studies. The content of these studies / actions is as follows:

  1. Basic Engineering: pipeline routing design and developing of the background for the process and instrumentation issues according to which, the detail engineering is based. The Basic design includes the final routing of the pipeline, contact(s) with public authorities, pipe and mechanical material selection and take off, technical specifications, design of the basic electrical and cathodic protection systems, design of instruments for communication and gas flow control, project cost estimation and management of the project technical documentation / archiving.  
  2. Environmental Impacts Study (EIS): preparation of scientifically substantial study investigating the impacts to the environmental systems of the regions to which the pipeline is passing through, from the construction up to the operation phase of the project. In the objective of the EIS are also included the legal constraints, the contacts with the authorities, the investigation of the environmental systems and finally, the environmental management plan of the project.
  3. Safety Study: preparation of a scientifically substantial study investigating the safety levels related with the gas pipeline to be commissioned and analyzing the potential risks and their consequences during the stage(s) of the project implementation / operation.
  4. Authorities Investigation / Permits Acquisition: investigation of the routing, in collaboration with the public authorities, for obtaining the pipeline routing licensing, as well as acquisition of all the legally required permits for the project implementation (i.e. Installation Act).
  5. Geological / Geolechnical / Geoelectrical / Seismic Studies: The Basic design of the project requires the execution of Geological / Geotechnical and Seismic studies along the pipeline route. In the scope of ASPROFOS services has been included the coordination and elaboration of an integrated geophysical study aiming to the evaluation and verification of the technical efficiency of the pipeline routing. The objectives of this specific study, are the following:

 

 

  • Seismo-tectonic analysis and evaluation of the seismic hazardousness along the pipeline route
  • Study for the correlation of the active and potentially active tectonic faults
  • Study for evaluation of the gas pipeline wall thickness
  • Mapping and evaluation of the geological / geotechnical conditions and formations
  • Geotechnical investigation comprising literature review and laboratory tests (cross holes, trial pits, SPT, CPT, soil chemical analysis, examination of the soil / subsoil mechanical properties)
  • Study of the geoelectrical conditions  

 

  1. Detailed topographical studies: execution of field geodetic measurements for recording of the right of way (ROW) zone along the pipeline route, elaboration of the detailed topographical / cadastral drawings and the corresponding cadastral registers, in which the physical /technical characteristics of the ground are depicted, as well as the geometrical shape of the landownership that is to be encroached and compensated because of the ROW preparation.

In the scope of ASPROFOS services is also included the Construction supervision of the project. More specifically, Construction supervision refers to the following:

  • Administration and review of the detailed engineering design which is elaborated by the Contractor
  • Supervision on site of the construction works and mechanical tests
  • Review of Contractor’s payment certificates
  • Technical support to the framework of third party inspection
  • Administration of issues related with the construction safety and quality management / control
  • Support to the Client by monitoring of the construction time schedules and reviewing of the Contractor’s variation order requests / claims  
  • Checking of the ‘’As-Built’’ documentation
  • Certification of the project completion and issuance of the provisional and final acceptance certificates of the pipeline construction phase.

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