Deep well sensing line

How do you blow out a well sensing line that is 500 feet deep?

 

By a well sensing line, do you mean an airline to determine the water level?

If so, the answer is with an air compressor or cylinder of nitrogen. Worst case scenario is if the static water level was at the surface, with 500 ft of submergence. 500 ft divided by 2.31 equals 216.5 psi. Now most sircimpressures will not go that high. That’s why I have a cylinder of nitrogen gas with a high pressure regulator. I actually used it yesterday. Not to check a waterline, but to run an impact wrench to change a tire. Now if your static water level were at 200 ft, you would only have 300 ft of submergance, and the airline will only inflate to 129.9 psi.