Pipeline leak detection system mimics the human body
When an engineer from Aberdeen University got a paper cut while reading research papers on the train, it lead to a Eureka moment that could save the oil and water industries millions of pounds. "I was actually reading about leakage problems in the UK water industry," explains Dr Ian McEwan, "when I cut myself on a piece of paper. Sitting there, holding my finger, it occurred to me that the human body does an excellent job sealing leaks…
By the end of the journey he had the nucleus of an idea for an innovative pipeline monitoring system that combined leak detection and repair.
Named ATLLAS (Advanced Technology for Leak Location and Sealing), the process developed by Dr McEwan and his team is based on the bio-physical analogy with the human body's own leak defence system.
Tests were first carried out using a specially designed flow-loop to characterise leakage in pressurised pipes. Data from a sensor array that was passed along the inside of the pipeline showed that a depressurised zone existed over the orifice created to simulate the leak. This depressurised zone caused the resultant fluid forces to entrain appropriately designed free-moving objects into the orifice.
This discovery lead to the development of the Platelet, a freefloating device designed to take into account flow velocity, pressure, product density, pipe diameter, leak geometry and leak size. The design is aided by advanced strength modelling using finite element methods as well as flow modelling using computational fluid dynamics simulations of both fluid and Platelet behaviour near a leak.
ATLLAS uses the fluid flow inside a pipeline to deliver these specially designed, polymer-based Platelets to the site of a rupture, where they are pulled into the leak and held in position by the pressure differential acting across them. The extreme pressure causes the Platelets to deform and meld together, temporarily plugging the leak. Tiny transmitters embedded into each Platelet allow pipeline operators to pinpoint the exact location of the fault.
Different situations require different Platelet specifications. Some applications emphasise the sealing capability whereas others may stress leak location. The exact specification of the material, which is inert and non-toxic, is part of this design process and takes into account strength requirements, ambient conditions and chemical compatibility with the product being transported in the pipeline.
The concentration of Platelets is sufficiently small that the effective density of the fluid is unchanged and excess Platelets can be removed from the flow using a downstream strainer system.
Just four years after that inspiring train journey, a spin out company, Brinker Technology Limited, was formed to market ATLLAS technology. Since then, the company has attracted interest, and investment, from leading players in the global energy sector. The technology is currently being developed for use in the North Sea Oil industry with the support of a Scottish Enterprise Proof of Concept Award.