The price of a barrel of crude oil is currently heading towards the magical 100 dollar threshold. This has led to noticeable consequences for the economy and consumers. In developing new reserves the focus is on the deposits off the West African coast which against this background are gaining in significance for future global energy supplies.

At present the Greater Plutonio oil field in Block 18, 177 km off the coast of Angola being developed by BP. The field covers an area of around 5000 km2 with water depths of around 1500 metres. The production installations for the valuable raw materials are all on the seabed.

Inspecting off-shore pipelines
Inspecting off-shore pipelines
Inspecting off-shore pipelines

From the individual drilling site underwater pipelines lead to a Hyperflow Riser Tower over a length of 1200 metres. In this way the oil reaches a Floating, Production, Storage & Offloading Unit.

The company Acergy was awarded the contract for designing and laying the pipelines. So that the "black gold" can be pumped from the depths of the ocean only pipes and pipelines of the highest quality can be used. Inspector Systems was awarded the contract to examine the inner coating of the 8" and 10" pipes, including the bends, and has created new standards in improving the quality requirements.

Deployment of INSPECTOR 4000

For this enterprise the video and laser inspection robot type INSPECTOR 4000 was used. This pipe robot, like all robots from Rödermark, is flexibly constructed and comprises several drive elements. In operation these are pneumatically pressed to the inner wall of the pipe and move with an inspection head with a pan/tilt unit and high-resolution colour camera.

A laser for measuring and classifying any damage is also integrated into the pan/tilt head. The point laser allows defects of > 2 mm to be measured. Its precision is better than 0.1 mm. With the aid of this pipe robot all the envisaged pipes (80 each of 12 m) and pipe bends (50 units) were inspected for fault in the inner coating. Defective points were also measured with the laser.

PMI examination of the inner coating

Individual damage to the inner coating was then inspected more closely. For this, INSPECTOR SYSTEMS in collaboration with Acergy developed an examination device for the PMI testing of the inner coating. Using a weak radioactive source and a detector a spectral analysis of the coating in the area of the previously visually detected area was carried out. This is known as "X- Ray Flourescence Spectroscopy".

With this measuring method the ferrite content in the Inconel coating was determined. In the event of too high a ferrite content and consequently possible corrosion damage an additional Gladding was welded onto the defective point from inside.