Corrosion, from long time before was a greatest problem in oil and gas industry and experts have always tried to combat this major problem. This has been given to the corrosion and inspection in oil and gas industry. Corrosion in oil and gas wells has the electrochemical mechanism, When the system reaches a temperature below the dew point, moisture is converted to liquid and many droplets occurs on the pipe's wall. In the electrochemical reaction, water plays role of the electrolyte. The water that creates was not corrosion by itself. When the acidic gases such as H2S and CO2 are dissolved in water create an acidic environment which in the vicinity of the steel will cause severe corrosion. Sometimes in oil wells, oxygen is one of the corrosive gases too. In the oil and gas industries, corrosion may be localized or uniform. Localized corrosion, can be create under the insulators, sediment and bacteria, was 10 to 100 times faster than uniform corrosion lead to destruction and there are many costs and risks associated with it.