Intelligent PiggingTowngas' Health Check for Its Transmission Pipelines

摘要

The Hong Kong and China Gas Company Limited, or locally called Towngas, has overrn140km of high pressure transmission pipelines operated at 35 barg transporting gas to over 1.6 millionrndownstream customers over Hong Kong. It is Towngas' prime goal to ensure a safe and reliablernsupply of gas.rnOne of the effective tools Towngas uses to evaluate the 'fitness' of its high pressure transmissionrnpipelines is intelligent pigging, which utilizes an electronic pipeline inspection gauge or 'pig' torninspect a pipeline without interrupting the gas supply to the downstream customers.rnIntelligent pig is not new in the gas industry but the technology is continuously being improved tornprovide more accurate, more comprehensive, more cost-effective and more user-friendly results.rnTowngas' internal policy is to do an intelligent pigging for each high pressure pipeline every 10 yearsrnunless the pipeline is not piggable. The result of the pigging carried out by Towngas in 2006 for fivernhigh pressure pipelines and the comparison of the pigging results with those 10 years ago has yieldedrninvaluable information on the health status of the pipelines and has proven the effectiveness of thernmodern intelligent pigging techniques in reducing the risk of a pipeline system.rnThis paper will give a brief account of how these were done and Towngas' methodologies andrnstrategies in the assessment and follow-up of the results.