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Advanced system and procedures assessing and monitoring of degradation of materials subjected to h2s environment

Development of off-line and on-line automated corrosion
advisors and monitoring systems to improvement assessment of
h2s damage risk. Furthermore, this could help to enhance
design/maintenance practices in oil and chemical industries.

In recent years, some significant incidents of cracking due to the effects of Hydrogen charging at low temperature have been recognised: a systematic inspection of pressurised equipment in wet H2S service revealed that about 20% of the 189 vessels contained significant cracks. The problem is of paramount importance with case tubing and pipelines which can be exposed to corrosive conditions. Furthermore, there are several circumstances where normal conditions progressively transform into corrosive conditions. For example, it is a common experience for oil and gas wells to become corrosive, particularly when water injection is employed. Lastly, it is well known that oil and gas treatment of offshore rigs will tend to be kept at a minimum, resulting in a more severe pipeline service environment. As a result of wet H2S service conditions damage in the form of StepWise Cracking (SWC) of the materials occurs. This is an HIC-related phenomenon. Sulphide Stress Cracking (SSC), a hydrogen embrittlement effect also occurs and both are able to produce cracking with catastrophic consequences. Thus the need for procedures and equipment to assess and monitor H2S properties and the degradation of materials subjected to an H2S environment is becoming indispensable. This proposal offers to develop off-line and on-line automated Corrosion Advisors and Monitoring Systems to improve the assessment of H2S damage risks. Furthermore, this development could help to enhance design and maintenance practices in oil and chemical industries. The project method is the following: - Thorough analysis of published works on effects of hydrogen on the fracture toughness of steels and welded joints in H2S environments; test methods in H2S environments; stress analysis significance of defects; corrosion monitoring; Non-destructive testing (NDT) used and evaluation of their performances. - Evaluation of test methods and development of techniques for measurements of Chemical Oxygen Demand COD(SCC), K(ISCC), COD(H), K(IH) and da/dt); 1516 Gr 60, 70; 1515 Gr 60, 70; 1285 Gr C; TMCP steel; X60; X65; X65 TCMP; X70. - Validation of fracture mechanics samples: optical and scanning electron microscopy. - Selection, testing and evaluation of NDT for assessment for wet H2S properties degradation (conventional techniques - manual, semi-automatic and automatic - and non-conventional techniques). - Development of NDT procedures and field validation. - In situ NDT crack propagation rate measurement for SSC monitoring - Modelling of SSC (stress analysis and propagation laws and crack size determination or propagation surveillance by NDT). - Finite elements modelling which incorporates parameters for hydrogen charging, materials resistance to SWE, SSC, HIC, SOHIC and failure mechanism. - Testing and validation of the model generated. - Selection, testing and evaluation of chemical and electrochemical techniques in the laboratory (polarization resistance - Tafel; impedance; electrochemical current noise; potential zero resistance Am-meter) to assess deterioration or corrosion rates and improve corrosion control procedures. - Field adaptation of chemical and electrochemical techniques and validity. - Design and implementation of software; - Development of H2S damage risk analysis instrument. - Industrial evaluation and validation of the integrated system.
Acronym: 
H2SCORR
Project ID: 
1 191
Start date: 
01-10-1994
Project Duration: 
63months
Project costs: 
2 600 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.