underground Oil leak

As most oils are more buoyant than water, a visual examination of the route of the line may be sufficient to give a first-order-of-accuracy as to where to start digging?

vkj,

Depending upon the viscosity of the oil, and the pressure under which the pipes are carrying it, the leaking liquid may actually be "heard" with specialized acoustical leak detectors.

Alternatively, the pipes would be temporarily emptied of oil, and filled with compressed air. The "hissing" of the escaping air at holes in the pipeline could then be pinpointed with acoustical/ultrasonic detection equipment.

Substituting helium or SF₆ for the compresseed air in the pipe, one could then use a gas-specific electrochemical or IR detector equipped with a soil-gas probe to locate the leak.

Also, ground penetrating radar (GPR) can also be useful in identifying leaks - however for a leak to be detected by GPR, it would have to be a sizeable one, or at least have been leaking for a while... (long enough for the released oil to have changed the "localized" soil density at the leak point).

Steam might be safer than compressed air from a flammability issue.

Depending on type of plant, ambient noise levels can cause problems with hearing the acoustic noise from a leaking pipe, so I would be very careful in researching that approach.

I would do some exploratory digging at suspected leak points, or drive in some 2" well points and test for oil presence at various underground locations..

How deep are the pipelines?

a good ''hydrocarbon leak detector" such as those used to check fittings and valves for leaks will often detect leaks of more volatile hydrocarbons-walk slowly along the lines sniffing the ground. Heavy fuels are more difficult to smell out.

Dear All,

Thanks for responding so well about the subject.

But in my part of the world, things are no easily avalable. Si I will be obliged If any specific intrument /Tools name,Model name, Brand name and manufacutrere is specified then it will be easier for us to evaluate and but them.

For example Telling only: the name as "Hydrocarbon leak detector or accoustical leak detector " is OK, but It will be nice if any manufacturer or supplier or specific Instrument name is specified to me as per "All GURU Ji's" experience then I can move forward more confidently from there.

Thanks and regards to all.