The work commissioned to Anese consisted in making 2 lines of pipes with the diameter of 300 mm, with a horizontal directional drilling method (HDD), on the gas pipeline, with a total length of 3086 meters.
It was essential to be able to carry out the TOC at a depth of about 35 meters to avoid the interfering with a series of wells for groundwater sampling present.
Moreover, the presence of a tour of several meters of gravel flimsy represented a sensitive issue during drilling.
Given that the gravel is a type of highly permeable soil, could pose a problem since it involves the outflow of sludge from inside the hole; and being a loose soil, tend not to keep skilled the walls of the hole.
At the end of the work, all steel pipes of DN 300 mm have been laid down.
9, 5 mm thick pipes were protected with polyethylene coating.
Two perforations were made: one from 820 metres and 2200 metres, which represented a record length in a single solution (one shot).
To resolve the problem of gravel, Anese chose to use a steel casing that pushed several meters depth up to registering in the substrate underlying cohesive, has allowed the drilling bit working conditions best, holding the sides of the hole widened and preventing sludge to expand throughout the gravel area.
- two lines of piping cutlery, setting a record (2200 m)
- water well field has not been invaded
- the casing had permitted to carry out the work despite the presence of gravel surface layers