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Oil accidents largely occur due to mining and transport by tankers, but also due to the pipeline transport. The reason can be a leakage of the pipelines and their damage caused by their age or external influences. The leaks of oil into the soil present a high risk because of their inconspicuousness, especially in case of a slow leak, which may go unnoticed for a while. Petroleum products are soluble in water, which may lead to the contamination of the surrounding groundwater. Self-monitoring of these transport systems is an important part of their operation. This article deals with the measuring of the leak by petroleum products using optical fibers. During the measuring, we use a distributed temperature system (DTS). The DTS is based on a principle of an optical reflectometer, i.e. the light impulse is transmitted to the fiber, part of the impulse returns back to the detector due to optical scattering. The phenomenon of the returning part of the light impulse is called the Stimulated Raman Scattering. The DTS can measure temperature along the entire length of the fiber in real time. Basically, we can imagine a thousand of sensors along the measured track with the accuracy of 1 meter. In this case, we have an optical cable laid down along the testing polygon. This testing polygon is intended to simulate the transport of the oil products in the pipelines. Many different leaks are simulated here. The measuring is based on the volatility of petroleum products and their ability to evaporate. The surface of the object, from which the oil evaporates, decreases in temperature. Sudden change in temperature at a given point detects a possible leakage of petroleum products. This leak can be immediately pinpointed with the accuracy of 1 meter and necessary intervention can be performed.
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