National Grid Gas Transmission (NGGT) aims to move away from predictive asset type modelling towards condition based monitoring of its critical assets. These assets are ageing and many have already reached the end of their intended asset life.
Partnered with two Small Medium Enterprises (Synthotech and Premtech) which have
proven records of success in innovation projects, NGGT is seeking to introduce in line inspection of below ground pipework at high pressure installations (AGIs), in order to determine the true condition of these assets. This will allow for pre-emptive fault detection, more targeted planned interventions to be undertaken, thereby extending the life of assets which remain in good condition and cost optimisation.
There is currently no available technology which can in line inspect below ground
pipework at pressure above 2Barg. AGIs operate pipework at up to 100Barg. Current
methods of inspection for below ground pipework AGIs involve visual inspection via
excavation which is both financially and environmentally expensive. As such it does
not regularly take place and reliance on survey techniques to target excavations is
favoured. These surveys only provide a partial view of asset condition and can be
inaccurate leading to unnecessary excavation to investigate potential problems. Not
fully understanding the condition of our assets increases the likelihood of an asset
failure at a high pressure installation which is also critical to our national infrastructure, such as those which supply power stations.
NGGT has a proven history of developing effective in line inspection technology,
evidenced through In Line Inspection (ILI) of pipeline via Pipeline Inspection Guages
(PIGs). As such it believes it can develop a robotic in line inspection device which can operate at up to 100Barg. This will allow NGGT to implement an intelligent and
proactive asset management strategy, reducing the requirement for inefficient and
expensive excavations, extending the life of assets and reducing the likelihood of an
asset failure at a high pressure installation thereby securing our national resilience.
Traditionally the onshore pipeline industry has only been able to in line inspect high
pressure pipelines using PIGs. In line inspection of pipelines provides the most accurate and reliable information on the condition of buried pipelines, other inspection methods external to the pipeline have a number of limitations. This innovative robotic technology will however increase precision in our predictive methods. Ultimately, below ground pipework on AGIs however cannot currently be in line inspected because of a number of engineering challenges associated with complex pipework geometries, lack of access and retrieval points and flow factors.
The project has 4 key objectives:
- To accurately and reliably determine the condition of high pressure below ground pipework at AGIs using an internal inspection robot.
- To generate a proactive, rather than reactive, risk based approach to the management and maintenance of aging assets, based on the knowledge of the actual condition of pipework.
- Minimise the occurence of annual unnecessary excavations and eradicate premature replacement of assets reducing significant carbon emissions and generating cost savings of circa £58m over 20 years.
- Minimise the likelihood of asset failure through proactive asset management, thereby significantly reducing the risk of a high pressure gas release into the atmosphere and the consequential financial, environmental and reputational impact.