Offshore staff

NIVELLES, Belgium -- T.D. Williamson (TDW) has completed a subsea hot tap intervention in the Egyptian sector of the Mediterranean Sea.

The operation was performed for main subsea contractor Technip Norge to facilitate tie in of a new 36-in. (91.4-cm) gas export pipeline to an existing 26-in. (66-cm) export line. The new pipeline will serve Burullus Gas Co.’s West Delta Deep Marine (WDDM) Phase VII development.

TDW’s main goal was to achieve the tie-in without shutting down production.

The program called for two conventional 16-in. (40.6-cm) hot tap operations on the existing 26-in. line. Additionally, a 20-in. (51-cm) hot tap on the new 36-in. line was performed on a blind weld-neck “tappable flange” made from duplex stainless steel.

To prepare for hot tap operations in water depths of up to 95 m (311 ft), TDW conducted engineering, design, and testing at its facility in Nivelles to customize a special hot tap tool known as a “cutter” to effectively cut the duplex plate. This cutter, which is more rigid than the standard tool, is vibration-free, the company says, and has a removable cutting tooth system for use on specific duplex tools.

For three weeks TDW personnel worked from Technip’s DSV Wellservicer to implement all three hot taps. The task on the duplex tappable flange took six days to complete. Throughout, a pressure of 100 bar (1,450 psi) was maintained in the 26-in. export pipeline.

In 2009, TDW provided similar services on parts of the onshore pipeline system that form part of the WDDM in Egypt.

05/27/2011