The International Gas Union (IGU) provides an opportunity for industry to research issues around gas distribution through its triennial program.
A research group led by Barbara Jinks was tasked with looking at unaccounted for gas (UFG) to identify UFG components, how UFG is measured, calculated or estimated, and to review approaches for UFG management.
After two and a half years, the research is now complete and the report will be presented at the IGU’s World Gas Conference, to be held in Kuala Lumpur from 4–8 June 2012.
What is UFG?Article continues below…
According to the IGU, the definition of unaccounted for gas is “the difference between the measured amount of gas entering a distribution system at the point of custody transfer, and that which is measured and billed at all delivery points over a defined period of time”.
UFG is important to public safety and can affect a distribution business’ finance and reputation. Dealing in a market where safety and reliability are critical, a large UFG result may be read as a sign of poor operational practice. It can be used as an external benchmark in comparison with other companies or as an internal trend indicator of company and industry performance.
How is UFG measured?
UFG can arise from physical, accuracy and estimation issues throughout the value chain of gas distribution. These issues aren’t always under the operators’ control.
Typically UFG is measured by subtracting the amount of gas sold from the amount of gas initially purchased from the producer.
Due to the complex and variable nature of UFG, it is not possible to design a single tool or formula for evaluation. No technical formula can be written, but rather estimating methods can be put forward.
Drivers – what causes UFG?
Research data shows that the top three drivers to address UFG are leakage reduction, meter accuracy and cost/efficiency. Companies currently spend most of their efforts to address UFG in these areas, including the reduction of third-party damage, permanent leaks (from older cast iron pipe) and theft.
The process of reducing UFG involves analysing all parts of the business to identify where UFG occurs.
Good management of gas meters is crucial to identify and measure UFG; a business cannot improve what it cannot measure. Adopted accuracy of meters can have significant impacts on UFG.
The way that meters, metering conditions and reading procedures are performed (including reading frequency, pressure regulation, procedures to minimise error and periodic accuracy checks) can greatly impact UFG and result in measurable improvements.