BIDI inspection of 3″ gas lift lines

Pipeline Description:

3 x 3” – 9km offshore gas lift loops. Bundled in rigid risers and sea line sections. Flexible jumpers connect the sea lines to risers and well manifold templates. 

Why is it challenging?

Wall thickness is 7.1mm, giving an ID of 74mm. The space available presents an important challenge to the construction of a magnetic yoke of sufficient strength. Even more difficult, an earlier profile and gauge run brought out a gauge plate that indicated a reduction of the ID to 58mm. At least one combination of 2.5D back-to-back bends is present. Although the tool traversing these bends could explain the gauge plate deformation, tool construction and design of the pigging program had to assume that 58mm was the actual minimum bore. 

Target of the inspection:

High resolution geometric (GEO) and metal loss (MFL) inspection.