TAP Including River Crossing

BONATTI J&P AVAX S.r.l., a joint venture between the pipeline contractor Bonatti and the Greek construction company J&P Avax, was appointed to construct the Greek segment of the TAP project. TDC was hired as a subcontractor for the application of 7mm pau wrap® on 3LPE coated steel pipes 48” (DN1200), for a total of 1.1. kilometers for sections 2 and 3, including the Aliakmonas river crossing. TAP consists of a pipeline running through Greece (550 km), Albania (215 km), Adriatic Sea (105 km), Italy (8 km). TDC had the opportunity to work on a segment of the pipeline in Greece near the border to Albania.

Due to the difficult geology of the terrain, which was discovered while on-site, the joint venture decided that pau wrap® GRP was the best solution for the environment. Originally planned as a Horizontal Directional Drilling (HDD) process for the two Aliakmonas River crossings, the inability to keep the pilot borehole open in the terrain resulted in the process changing to a Direct Pipe® system. The installation also resulted in further abrasion stresses and thus required GRP.

To avoid damages during drilling operations, both pipes and field joints were coated with TDC’s 7mm GRP, forming an integrated pau wrap® system. Pipe coatings were done in TDC’s factory in Trollenhagen, Germany and were then transported to Greece via rail. TDC had a total turnaround time of two and a half weeks from the initial arrival of the pipes to the departure of the unit train to Greece. The field joint coating was applied on-site by TDC’s qualified team at the same thickness as the pipe coating and on a Protegol polyurethane- based corrosion protection.

Environmental temperature conditions ranged from -8°C to 20°C, a fluctuation of 15°C during one work day was not abnormal, but the experienced TDC’s onsite team dealt with the weather conditions without causing any delays or quality issues during the application. Due to the fact that the pau wrap® curing process doesn’t require any kind of UV source during field joint operations, homogeneity and quality of the final product applied at site were equivalent to the factory applied coating.

The project was completed successfully with the TDC coating in April 2018 and passed all technical tests – the pipes evidenced no damages from the hard rock environment.

The project, Trans Adriatic Pipeline includes the shareholders: BP 20%, SOCAR 20%, Snam S.p.A. 20%, Fluxys 19%, Enagás 16% and Axpo 5%.

Update: April 2019