Working on the world’s longest undersea HDD recovery operation

Two parallel 3,050 m long steel pipelines were to be installed under the bay. The smaller one, to be used as a 609.5 mm oil trunk line, and the larger with a total steel pipe weight of more than 1,500 t, will serve as a 762 mm water injection line.

In November 2008, Tracto-Technik (TT-UK) was contacted by the Middle East specialist horizontal directional drilling (HDD) contractor Digital Connection Co Ltd of Al-Khobar, Kingdom of Saudi Arabia (KSA). The company sought technical advice and assistance in the recovery of a 1,066.8 mm hole-opener that had become stuck along with the 3 km drill string beneath the seabed during a pre-ream pass on the second of two under sea pipeline crossings.

The “˜Berri Causeway’ pipeline project in the Middle East (with high profile exposure to the trenchless technology industry) was always seen as a big challenge, for example the length of the crossings but also the dimensions of the pipeline which would weigh more than 1,525 t.

Whilst the first 609.5 mm oil pipeline had previously been successfully installed, unforeseen delays between the drilling process over a non-working 12-week period had caused the drill string and the 1,066.8 mm hole-opener to become stuck on the second 762 mm pipeline crossing/installation.

TT-UK, renowned for its expertise in the supply and service of its high-quality manufactured trenchless technology equipment, had little time to provide a solution to releasing the 3 km stuck drill string and 1,066.8 mm hole-opener.

To read more on how TT-UK solved this challenge utilising its “˜powerful’ Grundoram Taurus impacting hammer combined with steel pipe adaptations. For full article, visit the Pipeliner website.

For further information, please contact TTAP on 07 3420 5455 or email

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