The nature of LTS pipeline easements represents an asset management complexity. The monitoring methods used for transmission pipelines include aerial surveillance using helicopters and foot patrols along the pipeline route. These patrols prevent developments and events which could place the pipelines, the surroundings of pipelines or security of supplies at risk. Although these methods ensure a high level of safety in pipeline operation, the cost is also very high. Various agricultural practices remain permitted over the pipeline corridor, and recent changes in environmental policy allows natural processes such as lateral river movements across floodplains to go on unchecked by human intervention. It was once the case that artificial network defences were constructed, whereas now rivers migrate unimpeded. Where such river migrations place parts of the gas network at-risk, network licensees are responsible for redirecting their assets to accommodate these environmental changes.
Where allowable, visual inspections of around 2,400km of LTS network are conducted by helicopter surveys on a fortnightly basis. Helicopter surveys include a Raptor system of GPS-tagged full motion video, and the ability to annotate threat observations by on-board surveyors in real-time. In a small number of cases, immediate threats require the safe landing of the survey helicopter and direct intervention. Most threat observations however undergo secondary assessment through a systematic post-flight log review by asset managers. Subject to the nature and severity of the threat observed, asset managers will initiate any number of response mechanisms as defined by policy. Whether the threat is deemed an immediate threat or a normal threat observation, we face difficulty with the speed in which it may respond to a threat at all. For immediate threats, activities could conceivably have been occurring for up to 13 days prior to the survey acquisition, or it may be unsafe to land adjacent to an immediate threat, further delaying intervention.
Policy guidelines of fortnightly surveying is the result of risk/affordability assessment at the time of policy drafting, rather than a decision around the safety margin criticality for detecting and responding to threats in a timely manner. The policy goes further to state, “An aerial survey of all pipelines should be undertaken every two weeks. Normally, this activity is completed by an observer from a helicopter but can also be achieved by fixed wing aircraft or by the use of satellites.” As the existing policy contemplates multi-modal surveying techniques, the status quo of our current practices around LTS monitoring may be enhanced by using satellite imagery to reduce the overall risk to the high-pressure pipeline infrastructure and so deliver enhanced value to network customers.
Benefits
The status quo of our current practices around LTS monitoring may be enhanced in two ways, both of which would reduce the overall risk to the high-pressure pipeline infrastructure and so deliver enhanced value to network customers:
The nature of threat detections.
It may be possible using Synthetic Aperture Radar (SAR) and/or Visible Near Infrared (VNIR) and/or Short-Wave Infrared (SWIR) satellites for remote monitoring to improve the overall detection process across the complex asset network.
The timeliness of threat detections.
The satellite sensors have improved revisit rates over what was achievable just a few year ago. This coupled with; wide-area acquisition in a single overpass; cloud penetrating properties of SAR imaging; and sophisticated change detection algorithms and high-performance automated processing environments translates to an improved temporal window between threat initiation and threat detection.
NIA Project Registration and PEA Document 2021-07-22 3_17 (102.6 KB)
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NIA_SGN0150 Close Down Report 2021-07-22 3_17 (79.1 KB)
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NIA Project Registration and PEA Document 2021-07-10 9_42 (10.6 KB)
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NIA Project Registration and PEA Document (94.6 KB)
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NIA_SGN0150 (11-10-2019 08-26-36) (53.5 KB)
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NIA_SGN0150 (31-03-2020 14-47-10) (26.2 KB)
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project-difference (08-04-2021 16-34-12) (7.7 KB)
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SIMStage1 (08-10-2019 13-24-32) (53.3 KB)
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Learnings
Outcomes
Under the project a User Requirements and Business Opportunities report was carried out which detailed the value proposition of the concept. Our findings proved that the service has the potential to bring an improvement on our safety and environmental impact when monitoring our LTS assets that will increase the frequency of our inspection schedule as well as alleviating a lot of the pains from the conventional process including tracking inaccessible areas and showing geographical movements that is difficult to observe using the conventional process.
Once the value proposition was proven, appropriate test site locations were chosen to compare historic data captured by the helicopter runs to the satellite imagery. Criteria that was used when selecting the appreciate site is shown below:
An area that is representative of all the different encroachment types along a length of the pipeline
Presence of an historical time series of Cosmo-SkyMed SAR data and very high resolution optical data
Access to Raptor data collected from the helicopter surveys providing information on the location and type of encroachment, including photos where available. This is to be used as ground truth for the encroachments identified by satellite.
The testing results were a key output which assessed how the satellite analysis compares with and compliments the helicopter analysis. Through a series of service tests the findings of the tests are shown below:
Ground Movement monitoring through the use of InSAR technology is relatively mature and is a service that could potentially be implemented relatively quickly with little or no development.
Encroachment detection through the use of SAR data utilises modified change detection techniques to map potential activity within the vicinity of the pipeline network. Monitoring specific encroachments such as river courses could be implemented relatively easily as this type of slow moving, predictable feature is detectable on SAR data and can be easily tracked.
The technical assessment and conclusions drawn from the testing phase fed into a Service Development Plan which assessed the type and scale of the technical development work required to improve the processes for use in an operational service. Based on the technical feasibility undertaken, the activities to progress towards an operational service have been assessed and the operational developments to implement such a service have been documented. The service streams have been categorised in terms of development scope and timeliness of implementation. Some of the more mature service streams can be implemented in a relatively short timescale - within a year. For example a Ground Deformation monitoring service could be implemented across the SGN pipeline network relatively quickly. Other service streams will require a step change in technology before they can be realised. Our results has demonstrated how repeat coverage of the SGN pipeline network by satellite data can be achieved every two weeks. This has the potential to be expanded further to cover the networks of other Gas operators across the UK.
The Network Customer Benefit Report has presented an overview of how the development of a satellite based service to monitor and report on encroachments that threaten the integrity of Gas pipelines could benefit network licensees. The path from feasibility and technical development through to service implementation has been outlined and there are a number of aspects that are key to achieving this:
Prioritisation of the Service Streams – this ensures the streams that will provide the highest impact to SGN and the network licensees are the initial focus for development;
Use of Deep Learning Technology – this is a key technical development to achieve an efficient and reliable service. Speed of development is dependent on the collection of sufficient data samples to train the model;
Continual Improvement – the development of the service will not stop at the operational phase. It will continue to evolve as the service matures and new technology comes online;
Parallel service Implementation - the satellite based solution will deliver service streams that offer new and complimentary information compared to current monitoring methods. In the short to medium term, the new and existing services will run in parallel providing validation and training data;
Cost structure – this will consider the development and operational phases, ensuring the licensing cost of a future operational service reflects the investment and commitment of SGN and other network licensees
Lessons Learnt
This project progressed successfully from TRL 2 to TRL 3 which proved the concept of utilizing satellite technology to monitor LTS encroachment activity that can be used across the utility industry. Following completion of the feasibility study a number of observations were made which can be applied to other projects:
Having a user requirements workshop challenged what the potential of this project could bring which corrected any assumptions within the project team and helped set expectation within SGN.
Utilsing the value proposition canvas was a useful tool when ideating the pains and gains of what exactly the value proposition of the service is.
