Nucleom

The HTHA degradation phenomenon mainly occurs in the oil and gas industry. It affects carbon steels and low alloy steels, often in hydrogen reactors, pipes and pressure vessels. The HTHA inspection is important for the prevention of risks related to surface decarburization, cracks and splits.

HTHA stands for High Temperature Hydrogen Attack or Hot Hydrogen Attack. Nucleom offers HTHA inspections using a combination of techniques. Detection difficulties due to small sizes of methane cavities (<0.1mm) and misinterpretation of results from other reflectors such as inclusions are great challenges for NDT service companies. With this in mind, in addition to all the most advanced techniques widely used in the industry,Nucleom now offers a new HTHA inspection method resulting from several years of research to detect HTHA degradation as well as the risks of failure present . This new HTHA inspection method was developed by Frédéric Dupont-Marillia, PhD (R&D project manager at Nucleom), Joe Krynicki (EXXONMOBIL) and Pierre Belanger (PULETS).

SCIENTIFIC ARTICLE 

HTHA inspection according to the highest industry standards

Similarities in signal response between HTHA models and microstructural features have been challenges NDT/NDT companies have faced. Therefore, conventional HTHA inspections are performed using the combination of techniques listed below, with the aim of improving the probability of detection (PoD).

• Time-Of-Flight Diffraction (TOFD): Sensitive Technique for Weld Inspection LEARN MORE
• Phased array ultrasound (PAUT): Facilitated interpretation LEARN MORE
• Full Matrix Capture (TFM): Elimination of multiple setups, compared to the PAUT method LEARN MORE
• TULA: TOFD Ultra Low Angle to combine TODF and backscatter

In addition to detection sensitivity, the differentiation between inclusions and HTHA has always been a major issue for the success of an HTHA inspection. The team successfully completed the course of Lavender on HTHA detection and sizing for UT technicians. In an effort to improve diagnostic confidence, Nucleom has worked on an improved version of the HTHA inspection.

Nucleom's Advanced HTHA Inspection Solution

Our advanced solution is based on the principle that most of the imagery is the result of multiple averaging processes which decreases inspection sensitivity for small reflectors, such as the HTHA. Our approach combines advanced imaging that improves the performance of TFM by selecting consistent information. Then, when a suspicious area is identified, the S-Matrix is ​​applied locally to confirm the presence of HTHA.

Nucleom's methodology is as follows:

• VCF/DMAS
• TFM/PCI sans amplitude
• Scattering Matrix

Nucleom's solution is fully operational and relies on the highest industry standards as well as a new type of scattering matrix to validate the information collected.

Research and development

Cutting-edge R&D at Nucleom, conducted in partnership with public research, contributes to setting new standards in the non-destructive testing industry. As stated in our mission, Nucleom drives change by generating innovative ideas and inspection solutions that promote public and environmental safety.

To learn more about this innovative inspection method, see the latest scientific article entitled "Early detection of high temperature hydrogen attack using the ultrasonic full matrix capture and advanced post-processing methods" published by Frédéric Dupont-Marillia, PhD (Chargé de R&D projects at Nucleom), Joe Krynicki (EXXONMOBIL) and Pierre Belanger (PULETS).