How do natural gas companies know about gas pipeline leakage?

The hand-push buried pipeline leak detector is adopted and pushed along the pipeline on the ground, and the sampling suction port of the instrument always keeps in contact with the ground. In this way, meaningless detection can be avoided where there is no pipeline. At the same time, because the suction port is close to the ground, the gas has been inhaled once it has escaped from the ground before spreading, and even a small leak will be detected. Many of the leaks detected in the experiment are invisible to the naked eye. 

Only when the washing powder is poured on it will a small bubble emerge slowly.Pay attention to three points in the selection of leak detector:

(1) High sensitivity.

(2) The gas collecting hole must be close to the ground.

(3) Built-in pumping type is adopted.

After finding the abnormal point, it is necessary to drill a probe hole on the ground above the abnormal point, in order to guide the leaked gas to rise freely and vertically to the ground and provide objective basis for confirming the accurate position of the leakage point. Before drilling, the pipeline must be accurately positioned again to ensure the safety of the pipeline. The number of exploratory holes should be at least three, and the depth of exploratory holes should be as close as possible or exceed the buried depth of the pipeline (considering that the leakage point may be below the pipeline). According to different ground conditions, a variety of ground drilling equipment are used: a high-power electric hammer for penetrating drilling on hard and dense ground such as cement and asphalt; Drilling rod for deep drilling in soil and gravel layer. The length of the drilling rod will affect the depth of drilling. 

Generally, the drilling rod with the depth of 1.5m can be used in northern cities. In southern cities, it is enough to choose a drill rod that can drill 1m deep. The selection of drilling rod should have considerable rigidity, aiming at dry and dense old soil layer; At the same time, in order to deal with the larger gravel and flaky in the soil layer, the drilling rod should be flexible enough to automatically turn around the gravel or flaky. After the boreholes are drilled, it is necessary to measure the gas concentration of each borehole one by one. At this time, because the probe hole is deep into the pipeline, the leaked gas will escape out of the ground along the probe hole. Therefore, the accurate location of the leakage point can be judged by comparing the concentrations measured by each probe hole.