The role of Earth Cover and Compaction Level on the Natural Gas Leakage rate from micro holes in an underground pipeline

Pipeline is the cheapest and approachable source of transmitting Natural Gas (NG), but due to small holes in the natural gas pipeline makes it threat full and disposed to Unaccounted for Gas (UFG). It is very difficult to detect a leak and then to rectify the observed leak due to which it takes time. A huge amount of fugitive NG is therefore leaking through the pipeline which not only accounts for the UFG and atmospheric pollution but extreme amount of natural gas in the workstation can surely lead to accidents. The purpose of this study was to find out the quantity of leakage rate due to micro hole in the medium pressure NG pipeline used in the distribution network and the reduction of leakage rate due to the earth cover and compaction level of the soil. For this purpose an experimental rig was designed to study the leakage rate from the pipeline when placed in air (above ground) and underground. It was observed that the quantity of leakage substantially decreased due to the earth cover on the leaky pipeline and the increased in the relative compaction of the earth cover, thus reducing the UFG, environmental and economic loss. An average of 28.8% and 52.5% reduction in leakage rates were observed, when gravely clay was compacted to a relative compaction of 55% and 71% respectively.