Learnings

Outcomes

Following the completion of the first two phases of this project, and the laboratory demonstration of a proof of concept, as per the aim and objectives have been satisfactorily completed. This work has successfully demonstrated defect detectability on carbon steel pipeline, in multiple different configurations, using infrared thermography. Further details of the findings and outcomes of the project are captured in the Thermography Project Final Report 

Below are conclusive extracts from the Thermography Project Final Report provided to National Gas. 

·       With increasing excitation time, defects become more ‘visible’ (higher temperature discrepancy). 

·       Passive mode inspection is successful with defects that have a larger depth as the temperature discrepancy can be maximised. 

·       Dynamic inspection with an excitation source running parallel yields the best results due to a constantly replenishing source of energy for the camera to pick up. 

·       The average temperature discrepancy change as speed increases is -8.1 °C from 5.9m/min-20.5m/min

·       Maximum temperature discrepancy seen by the test results was in active-dynamic mode (10mm defect) at 69.3°C 

·       Defect geometry calculations have a maximum fluctuation of 0.1% in dynamic-active mode inspections (this can be corrected with a factor in post processing).

·       High energy convectional heating systems will not be suitable for low depth defects such as the existing ones found on the pipeline section (unless there is constant heat flow passing through the defect). 

·       Stitching algorithms have a specified number of frames per stitch (per unit length) that yield the best results with least errors. This number lies between 40-70 over a 1m inspection length.

Following the completion of Phase Three, a full technical report of all the learning, goals and outcomes was provided to National Gas along with several other supporting documents i.e. Statement of Requirements, master schedule and an academic white paper, “Quantifying Uncertainty in Pulsed Thermographic Inspection by Analysing the Thermal Diffusivity Measurements of Metals
and Composites” that had been developed during the project. 

The project was able to demonstrate that Thermography can be used to detect defects, surface and sub-surface to a standard that is applied currently with the NTS framework. Further work will be necessary to establish thermography’s capability within a controlled test environment exposing the thermography system to gas flow and pressures, a test location such as  Spadeadam is proposed 

Value tracking  

Data Point                                        Data Point Definition 

Maturity                             TRL2-3                                               Research project 

Opportunity                   <25% of single asset class              The use of thermography is focussed on the inspection of our pipelines 

for this project.  However, the low TRL and operating speeds of the    t            echnology limits its current usage. 

Deployment costs             -                                                        Current phase of project is not evaluating the cost for deployment. This  

will be explored further once the technique is proven and the application has been chosen 

Innovation cost                  £155,793                                           Cost of innovation project 

Financial Saving                 -                                                        Financial savings are not currently identified due to early TRL level.  

Savings could be made via improved defect characterisation. 

Safety                                 -                                                        Safety improvement not currently known. Safety benefits could result  

from improved characterisation of pipeline defects 

Environmental                   -                                                        No direct environmental benefit 

Compliance                        Support Compliance                        Results of this project could help support pipeline integrity compliance for  

Hydrogen pipelines 

Skills & Competencies       Departmental                                   Could result in new technique available for pipeline engineers to utilise  

for pipeline inspection 

Future proof                      Supports business strategy              A technique for improved defect characterisation on our pipelines shall  

benefit our transition to a Hydrogen network

Lessons Learnt

1.       The initial submission to review Thermography as an alternative In Line Inspection technique was based on the literature research and market scanning in conjunction with exploratory investigation work carried out by Cranfield University. Post Phase One it was evident that whilst thermography could provide potential increased inspection capability high speed In Line Inspection with thermography was not a viable option and hence the revised focus from high speed inline Inspection to a lower speed Robotic GRAID was identified. 

2.       The original Commercial agreements suggested that this background work and the implementation considerations that were planned to be completed during phase 1 however given early TRL 2-3 the project was only able to identify operational requirements and standards required for thermography. As the project learning identified limitations and opportunities the ability to assess against financial factors and stakeholders’ assessments were too early. A learning point would be that given this was an exploratory piece of research areas that would have been covered in the commercial research and implementation should be subject to later phases.  (TRL 4)

3.       As with most research projects at TRL 2-3 possibilities become apparent as new facts and opportunities are discovered which increases the temptation for project scope creep. After the Phase One project review the revised project scope to include the potential GRAID opportunity and multi-sensory demonstrators should have been assessed in parallel to avoid distraction for Phase Two R&D activity – project next steps cited in the Final Project Report will consider the additional requests.    

4.       Although sample pipe was provided the level of known defects on the samples were limited. In addition, the external surfaces were coated in bitumen which could not be removed at the University due to H&S restrictions. This resulted in defects been reproduced to simulate potential defects and features. The project would have benefitted from access to additional representative samples for analysis, this requirement is cited for future project activities.

5.       Contract delays between the parties took an excessive amount of time. Engaging Cranfield University due to their operating position required several contract iterations around liabilities. Longer term the lessons learnt from developing the contractual clauses will inform future contractual definition and criteria to work with National Gas.