In order to improve the efficiency of leak detection surveys of high pressure natural gas pipelines airborne laser based detection methods have been developed during the last decade. Diverse requirements and individual gas guidelines in various different countries were the basis for quite a variety of airborne gas remote detection systems.
This contribution to the PTC will focus on the plurality of airborne gas remote detection systems, their characteristics as well as their pros and cons. Special attention will be given to the application of the systems and hence to the related requirements.
In Western Europe the CHARM® system is in operation on a regular basis, CHARM® is certified according to the German gas guidelines and hence fulfills leak detection surveys at the same safety level as walking surveys. Additionally, CHARM® features a further increased reliability, a photo documentation of the pipeline tracks and much shorter operation cycles. Based on these advantages several European gas transmission companies decided to apply a CHARM® survey instead of long duration walking missions. Nevertheless, situations exist where walking gas detection operations are advantageous compared with airborne surveys. These practical details will be presented based on the experience of several years of CHARM® operation.
An additional chapter focusing on data evaluation and the avoidance of false alerts as well as an outlook to actual and future developments will complete this paper.