Norwegian oil company Statoil are using a titanium drilling riser on the Heidrun platform.

Titanium is a very light material for its strength compared to steel but requires careful inspection because crack growth rates are relatively high.

Statoil required an NDT technique capable of inspecting key ares on the riser, including the inside wall which is covered by a (5mm) thick bitumenised rubber protective coating. ACFM was chosen as the most suitable technique and TSC developed a range of array probes for different parts of the riser joints (including lifting grooves and stud threads).

For inspecting the main body of the joint, TSC working with Phoenix Inspection, produced a motorised scanner to deploy four separate array probes around the outside of the riser. This system is now in regular use.