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Projects: Projects for Investigator
Reference Number	NIA_NGGT0085
Title	New techniques for the measurement of pipeline depth of cover
Status	Completed
Energy Categories	Fossil Fuels: Oil Gas and Coal(Oil and Gas, Refining, transport and storage of oil and gas) 100%;
Research Types	Applied Research and Development 100%
Science and Technology Fields	ENGINEERING AND TECHNOLOGY (Mechanical, Aeronautical and Manufacturing Engineering) 50%; ENVIRONMENTAL SCIENCES (Earth Systems and Environmental Sciences) 50%;
UKERC Cross Cutting Characterisation	Not Cross-cutting 100%
Principal Investigator	Project Contact No email address given National Grid Gas Transmission
Award Type	Network Innovation Allowance
Funding Source	Ofgem
Start Date	01 January 2016
End Date	01 January 2017
Duration	12 months
Total Grant Value	£196,000
Industrial Sectors	Technical Consultancy
Region	London
Programme	Network Innovation Allowance
Investigators	Principal Investigator	Project Contact , National Grid Gas Transmission (100.000%)
Web Site	http://www.smarternetworks.org/project/NIA_NGGT0085
Objectives	Investigate the feasibility of using a new methodology to identify areas of reduced depth of cover on a buried pipeline. Deliver of a technical report documenting a methodology and the results from a trial on 1 pipeline including in-field validation.
Abstract	Third party interference is widely documented as being primary source of damage to buried pipelines within the UK. In addition to routine surveillance, depth of cover is recognised as a primary method of mitigation against third party interference, therefore ensuring that the depth of cover is adequate is important to reduce the likelihood of third party interference occurring. Current depth of cover measurement techniques are deployed in the field and only provide spot measurements, therefore any close interval depth of cover surveys for an entire pipeline require a considerable amount of effort. Develop a methodology to effectively identify areas of reduced depth of cover over an entire pipeline. This would support National Grid in reducing the likelihood of third party interference events occurring. As part of the trial, it is proposed to utilise pipe location data obtained from internal pipeline inspection to provide an accurate position and elevation profile for the entire pipeline. The trial will combine pipe location data from in-pipe inspection with ground elevation data and other applicable data sources, to identify areas of reduced pipeline depth of cover. The following discrete tasks are proposed. It should be noted that all tasks are required to complete the trial. Task 1 - Technology Survey The project will undertake a survey of available literature related to technologies that can be used to locate reduced depth of cover on buried pipelines. Information will be obtained from published studies, manufacturer’s literature, internet search and personal correspondence. The technology survey will consider technologies for: 1) direct measurement of depth of cover, 2) mapping of buried pipelines, and 3) acquisition and derivation of digital elevation models. The output from this task will be a short technical report which will discuss and document technologies and, where appropriate, offer guidance to the remainder of the tasks to be completed in this proposal. Task 2 - Inspection Preparation To ensure that an accurate position and elevation profile of the pipeline is obtained from the internal inspection, thorough preparation is required. NGG currently use ROSEN to undertake internal inspections of the buried pipeline, specifically with the remit to identify corrosion or damage to the pipeline which may impact pipeline integrity. As part of the inspection an inertial measurement unit is included with the inspection tool (often referred to as a pig), the inertial measurement unit provides data to identify changes of direction along the pipeline i.e. bends. This data can be processed following the inspection, to provide an accurate map of the pipeline for use in a geographic information system (GIS). To complete this inspection ROSEN will provide an optimised inertial measurement unit to ensure that accurate pipeline position information is collected during the inspection. In addition to the optimised inertial measurement unit, accurate tracking of the inspection tool is required. This is achieved by deploying above ground markers, prior to the inspection tool being launched, which are detected by the inspection tool. Accurate position data (differential GPS coordinates of the marker and depth of cover on the pipeline) at each above ground marker is used to correct for drift in the IMU, thus improving the accuracy of the pipeline coordinate data used for input to GIS. To complete this study it is proposed todeploy above ground markers at 0. 5 km intervals along the pipeline. It is recognised that this may be time consuming to complete and therefore this study will also evaluate the impact on accuracy of the results for a range of marker intervals. Task 3 - Internal Inspection It is proposed to trial this methodology on a pipeline that is currently scheduled for an internalinspection1. The optimised inertial measurement device will be included within the inspection tool for this inspection. The costs to complete this inspection are not included within this scope of work. The internal inspection will be completed in accordance with NGG policies and procedures and undertaking this trial will not comprise the quality of the data retrieved for the purposes of evaluating the pipeline integrity. Task 4 - Post Inspection Data Processing Following successful completion of the internal inspection (Task 2) post processing of the data obtained from the IMU will be completed by ROSEN. The output from this will be an accurate centreline profile for the pipeline, provided in a GIS compatible data format. Completing the post processing of the IMU data will not impact the delivery of the standard inspection data required by NGG policies and procedures. Task 5 - Depth of Cover Assessment To identify areas of reduced depth of cover, accurate ground elevation data above the pipeline is required. It is proposed to utilise a national database of Light and Detection Ranging (LiDAR) data available from the Environment Agency. This database has a vertical accuracy of between 5 and15 cm, at a horizontal resolution of between 25 cm and 2 m. MACAW will integrate the ground elevation data with the position and elevation data for the pipeline in a geographic information system (GIS), to identify areas of reduced depth of cover. MACAW will use additional data sources such as geology, flooding data and the position of other features such as watercourses and traffic routes within this assessment to diagnose possible causes for the reduced depth of cover. The output from this task will provide up to 10 locations of suspect reduced depth of cover for infield verification within Task 5. Task 6 - In-Field Verification In order to verify the results from the depth of cover assessment, it is proposed to undertake in-field verification at up to 10 locations along the pipeline. This will be completed using a pipe and cable locator which has the capability to measure the depth of cover above the pipeline. Depth measurements will be taken at the locations of suspect reduced depth of cover identified in Task 4 and these will be compared with results obtained from the depth of cover assessment. Successful completion of the in-field verification will provide important information regarding the absolute accuracy of the depth of cover assessment. 2. 7 Task 7 - Report and Presentation of Findings A technical report summarising the tasks undertaken within the study and documenting a methodology to identify areas of reduced depth of cover on a buried pipeline will be delivered. The report will include the assessment of one pipeline. The delivery of the technical report will be supported with a GIS compatible database containing the accurate pipe position, ground elevation and estimated depth of cover along the pipeline. This data can be utilised by NGG to determine if remedial measures are required at any locations along the pipeline. A summary presentation of the key findings and conclusions from the project will be delivered to key Stakeholders within NGG.Note : Project Documents may be available via the ENA Smarter Networks Portal using the Website link above
Publications	(none)
Final Report	(none)
Added to Database	14/09/18