This paper provides an overview of recent major research and development activities from the Energy Pipeline Cooperative Research Centre.
by Alan Bryson, Principal Corrosion and Integrity Specialist, Corrosion Control Engineering
In late 2009, the Energy Pipelines Cooperative Research Centre (EPCRC) was established for the purposes of providing research and education to support and benefit the energy pipelines industry in Australia. It is a user-led CRC with its industry participants represented by the APGA Research and Standards Committee (APGA-RSC). The research participants were the University of Adelaide, the University of Wollongong, Deakin University and RMIT University.
The CRC was supported by a combined $27.480 million from the Commonwealth and industry as well as a $50 million in kind contribution from the universities and the Australian pipeline industry. This funding was spread over the 10-year life span of the EPCRC.
The four research programs of the EPCRC were Materials; Coatings and Corrosion; Design and Construction; and Public Safety and Security of Supply.
The research program primarily focusing on pipeline corrosion mitigation was research program 2 (RP2), extending the life of new and existing pipelines which focused primarily on life prediction, cathodic protection, performance of pipeline coatings and stress corrosion cracking (SCC).
Key projects undertaken by RP2 include:
Quantifying corrosion rates because of short duration anodic transients as experienced from DC stray current traction systems and telluric currents
This research project aimed to systematically categorise and quantify the level and nature of damage as a result of cathodic protection excursions, which may occur by the various modes of stray current, traction and telluric influences that can shift the pipeline potential significantly positive of the desired -850 mV CSE (protected) level for periods that may be long or short [3]. As a result of this research, the cathodic protection criteria for short duration excursions in AS 2832.1 was modified.
Assessing cathodic shielding under disbonded coatings
One of the greatest issues with nominally cathodically protected pipelines is shielding of cathodic protection by coatings that have disbonded. This issue has become more prevalent as pipelines have aged and coatings have deteriorated.
A greater understanding of the impact on corrosion of these coatings and the susceptibility of different coatings to disbond and shield have enabled industry to focus asset management programs on the most ‘at risk’ pipeline sections.
Assessing coating performance, particularly field joint coatings
The notions of long-term durability and mitigation of pipeline corrosion were of critical importance and the subject of research in this project. The impact of poor joint coatings often culminates in corrosion, and the mitigation of corrosion requires attention to corrosion rate, type and protection (via cathodic protection systems).
Overall, corrosion is an extremely costly and significant threat to the integrity of pipelines and potentially to the safety of the public. The failure of joint coatings is one of the major concerns in corrosion protection of pipelines.
Additionally, an area that also received specific attention in this project was the coating performance and possible deterioration during the pre-commissioning hydrotesting.
Development of real-time corrosion monitoring sensors
This project aimed to develop, evaluate and practically apply a pipeline condition monitoring (PCM) system by installing suitably designed sensors on semi-field testing pipeline and on real life energy pipeline sections, in particular, on strategic and ‘worst-case scenario’ pipeline sections between cathodic protection units (CPUs), non-piggable pipeline and other high risk pipeline sites.
Pipeline life prediction and modelling and decision-based systems
The aim of this project was to develop a system to benefit the industry by transforming the way pipeline asset management is undertaken by offering a more reliable prediction of pipeline degradation due to corrosion and coating durability, and hence service life, together with processes for integration of the predictive models into owner organisations’ asset management systems.
A predictive tool (based on empirical and deterministic modelling) may be used for life prediction, and for intervention planning and strategies for altering deterioration rates or remedial treatments.
Benchmarking Australian stress corrosion cracking (SCC)
The SCC crack morphology in the Australian pipelines is known to be different to that reported for SCC occurring elsewhere in the world, rendering overseas SCC crack growth models potentially unsuitable for Australian conditions. The characterisation study allowed existing SCC models, both local or international, to be refined and be applicable to Australian conditions.
The tomography, mechanics and interaction of inclined SCC
Previous work suggested a cause for the complex stress corrosion crack paths found on Australian pipelines could be due to local metallurgical conditions, particularly crystal orientation (texture). Additionally, the reasons why nominally identical adjacent pipes display different susceptibilities to SCC have not been explained.
The objective of this project was to increase the understanding of the role of pipe microstructure, chemical composition and pipe metallurgy on the SCC crack path in an Australian pipeline. Research was also undertaken to relate manufacturing processes to microstructures with a lower SCC susceptibility in a quantifiable manner, such that it will be possible to determine if modern pipes can offer increased SCC resistance if the coating fails.
Assessing pipeline and coating condition of pipelines installed using horizontal directional drilling
Horizontal directional drilling (HDD) is becoming a widely used method of pipeline installation. This project explored the improvement of existing methods of assessment of the coating of HDD installed pipelines. This resulted in the development of a new method based on the measurement of local electrochemical impedance spectroscopy (EIS) along an HDD pipeline that is able to estimate not only the area, but also the location of coating damage, before and after HDD pipeline construction.
Research was also undertaken to develop a standardised test method for assessing the expected gouge resistance performance of coatings that are used on pipelines installed via the HDD method, thereby allowing industry to rank the coatings performance. As a result, a new test methodology and test rig was developed that is now available for use at the National Facility for Pipeline Coating Assessment (NFPCA).
Establishment of the NFPCA
The NFPCA is unique in Australia and is essential for building up a capability for pipeline coating selection, research and development. The NFPCA performs standard and custom-designed pipeline coating testing to fulfil the needs of the Australian energy pipeline industry.
The further enhancement of the NFPCA was achieved by achieving NATA accreditation, by extending its research capabilities in coating flexibility assessment and in cathodic disbondment testing, and by meeting pipeline coating application and field-testing need. The EPCRC concluded its term in June 2019; however, research reports are available in its database for industry to search and use.
Future research and development activities
On 1 June 2018, the Assistant Minister for Science, Jobs and Innovation Senator the Hon Zed Seselja announced the Federal Government’s CRC program will be co-funding Future Fuels CRC (FFCRC) with
$26.25 million over its proposed seven-year research program. The combined investment from the Commonwealth, Australia’s Energy Industry and universities (cash and in-kind support) will total more than $90 million over the life of the program.
The three key program areas for the FFCRC are:
- Research Program 1: Future Fuel Technologies, Systems and Markets
- Research Program 2: Social Acceptance, Public Safety & Security of Supply
- Research Program 3: Network Lifecycle Management
The work of the FFCRC will support Australia’s energy infrastructure to equip for new emerging fuels and technologies.
Acknowledgments
Much of the material in this paper has been sourced from the EPCRC, supported through the Australian Government’s Cooperative Research Centres Program with funding and in-kind support from the APGA RSC and the Victorian Electrolysis Committee Resource Manual.
Thank you to Mike Tan of Deakin University, the EPCRC for permission to use information from their website and the Victorian Electrolysis Committee and Energy Safe Victoria for permission to use material from the VEC resource manual.
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