Solutions to Pipeline Graphitisation and Corrosion - Stage 1 - Concept Development

Completed

Fossil Fuels: Oil Gas and Coal(Oil and Gas, Refining, transport and storage of oil and gas)

Applied Research and Development

PHYSICAL SCIENCES AND MATHEMATICS (Metallurgy and Materials)
ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering)

Not Cross-cutting

Project Contact
SGN

Network Innovation Allowance

Ofgem

01 June 2015

01 June 2016

12 months

£146,367

Energy

South East

Network Innovation Allowance

Project Contact, SGN

This project aims to prove the concept of dealing with the issue of pipeline corrosion and more specifically to: 1. develop systems to prevent the onset of pipeline corrosion2. develop systems to arrest existing corrosion processes in pipes3. develop systems to remediate pipelines suffering from corrosion. Furthermore, the possibility of providing an option of embedded condition monitoring for repairs will be investigated to deliver ongoing assurance of any pipeline repairs. Recommendations for and progression to the next stage of development. The following success criteria apply to this project: Creation of solution specification. Generation of concepts for investigation against solution spec. Completed initial feasibility assessment of concepts. Selection of up to six concepts for initial testing Initial testing of selected concepts. Completed full project report documenting findings and recommending next steps.

SGN operates two of the largest gas networks in the UK, providing a safe and secure supply of natural gas to 5. 8 million customers through 74,000 km of gas mains and services. A significant proportion of these networks comprise cast iron pipelines, some of which have been in service since the late 19th century. Although these pipelines have served the industry well they can suffer from a form of selective corrosion known as Graphitisation. The 11,500 fracture and corrosion failure events and 940 ‘gas in building’ events reported in 2004 show that a large number of these pipelines are reaching the end of their lifetime. Current Health and Safety Executive (HSE) legalisation has determined that Gas Distribution Networks (GDNs) must replace all cast-iron gas mains within 30m of properties - this means that over 101,000km of iron gas pipelines will have to be replaced by 2032. Graphitisation, or graphitic corrosion, is the process by which in certain conditions, the iron component of cast iron pipes is selectively leached out, leaving the much weaker graphite component of the pipeline. This results in an increase of pipeline failures and their associated remediated costs. During SGN’s current Large CISBOT pilots being carried out in London and Edinburgh, pipeline coupons have been routinely analysed by a technical services provider, DNV. GL. Graphitic Corrosion has been detected on all samples to date with pipelines suffering from between 20% to 60% graphitisation. It can therefore be assumed that this is an issue that affects all cast iron pipelines within SGN’s (and the rest of GB’s) gas distribution networks. The forecasted decommissioning lengths of at risk tier 2 and 3 mains under RIIO-GD1 is weighted towards the end of the price control period to allow time for investigations into pipeline issues to take place and to develop solutions. Ofgem’s definition of ‘Decommissioning’ includes other risk intervention measures and is not limited to physical decommissioning, therefore any development that can address pipeline issues such as Graphitisation has the potential to assist in creating both cost and time efficiencies in meeting RIIO GD1 Tier 2 and 3 targets. This project aims to approach the issue of pipeline graphitisation by developing concepts that can address the problem in one or all of the following ways; preventing, arresting, or remediating. These concepts will then be refined and undergo assessments to determine which should be moved on to the next project phase - Development Engineering. From a high level perspective, solutions can be grouped by function: ; Prevention of the onset of degradation occurring; Arresting further degradation preventing the situation worsening; Remediation where degradation has already occurred; Furthermore, the possibility of providing an option of ongoing condition monitoring for repairs will be investigated to deliver ongoing assurance of any pipeline repairs to complement the 3rd party inspection equipment being developed by SGN in alternative projects. The project will examine solutions for all of these four categories, though it will focus on technologies to prevent, arrest, and remediate the pipelines, with the aim to develop up to six technology concepts. An ideal solution would be a process of reversal of the corrosion whereby the iron or steel component is replaced in the corroded areas. If this is not possible then aremediation method which replaces the strength attributed to the missing iron would be desirable. It is appreciated that this is a highly complex challenge requiring significant innovation and multi-disciplinary expertise. In order to minimise the risk to SGN, the work is planned to be carried out using a stage-gate approach. This NIA project scope describes the work packages for Stage 1 (concept development) of the overall proposed project which has been designed over 4 stages: Stage 1 - concept developmentStage 2 - Development EngineeringStage 3 - Testing and ProceduresStage 4 - Field TrialsNote : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above

14/12/18