Highly flexible probe makes offshore production safer


Experts from TÜV Rheinland have developed a new probe for inspecting the corrosion of offshore oil and gas wells. The inspection tool features a caterpillar track design, is over 1 m long and is as agile as a snake, it is claimed. Unlike previous inspection probes, the PEC Snake can penetrate through a 2" hole or a 2" side valve arm. 

The highly flexible probe easily enters through sharp bends and can still be moved into tight spots on offshore platforms, such as between the conductor and the surface casing. 

“The inspection tool has successfully passed its field test in the North Sea and is now available for use on offshore oil and gas production platforms worldwide,” said Sergey Putintsev, Managing Director at TÜV Rheinland. “The test results provide operators with important information about the degree of corrosion and the mechanical integrity of the offshore structure and help minimise the risk of well collapse.”

The probe is equipped with a special ‘whisker’ mechanism that serves as a positioning system to correctly position the miniaturised pulsed eddy current (PEC) sensors against the conductor and casing. The inspection is performed with PEC probes and is suitable for both operating and abandoned wells. A 90 m cable nearly doubles the operating range compared to other existing probes. The test results provide important information about the degree of corrosion and the mechanical integrity of the offshore structure, minimising the risk of a well collapse. 

“The PEC Snake is a major technical breakthrough that enables oil and gas operators to prevent fatal casing, conductor or entire well failure,” said Riccardo Scottini, Product and Business Development Manager at TÜV Rheinland. “Thanks to the smaller access and longer probe cable, the new Sonovation device can be used in many types of offshore production operations around the world.”

For cases where the well annulus between the conductor and the surface casing might be cemented or grouted, TÜV Rheinland experts use an improved version of the previously used C-PEC probe, which is ATEX certified. This probe has been further developed specifically for accessing the borehole annulus between the surface casing and the intermediate casing.