Substitution of Riga-Panevezys pipeline underwater pass through Daugava river basin


2010 – 2011


Latvijas Gaze JSC

Construction of the underwater part of the pipeline using horizontal directional drilling (HDD) method. Laying of a new DN 700 pipeline under the existing  DN 500 pipeline, at a depth of ≈ 30 m from the water surface. The length of the pipeline is about 1.7 km, including 1.5 km HDD tunnel. The working pressure is 55 bar.

Scope of work:

  • Design and detailed design documentation  (including geological survey);
  • HD drilling;
  • Procurement of the materials;
  • Initial welding of the underwater pipe segments into two ≈ 775 m sections on one river side and pulling into drilled borehole;
  • Construction of temporary bypass lines DN300 and connection to back up pipe DN500 and main pipe DN700 at the ends of the substituted sections;
  • Installation of PE pipe DN200 for drilling mud circulation
  • Installation of backup communication cable
  • Pipeline commissioning and putting into operation;
  • Existing pipeline disconnection and dismantling.