Pipeline inspection and maintenance via acoustic methods and tools

There is a wide variety of pipeline inspection tools and each one has its advantages and limitations. This paper presents a study used for the develop-ment of a novel pipeline inspection tool for the oil and gas industry using acoustic reflectometry. A review of inspection techniques is presented with a focus on acoustic techniques as reliable and accurate inspection methods. A set of experi-ments are carried out to investigate acoustic reflectometry as a pipeline inspection tool. Inspection of a single leakage, a fault 1.5 mm in diameter, in a 30 m straight pipeline is carried out in order to detect and locate it as accurately as possible with the acoustic wave being injected from one side of the pipeline. Then a relation be-tween the reflected leakage signal amplitude and the leakage size is established and described so that the leakage size can be estimated if the signal amplitude for the particular pipeline setting is known. In order to obtain a high amplitude re-flected signal to maximise energy input, an injected signal frequency needs to be properly chosen. This helps to read the fault signal easily and precisely. This ex-periment was repeated each time on a single leakage (1.5 mm in diameter) for five different distances from the signal injected. This was then repeated for the same distances from the acoustic wave injected with additional sized leakages: 1.5 mm, 2 mm, 2.5 mm and 3 mm in diameter. Hence, the fault signal amplitude which re-sulted from various injected signals is analysed and presented with respect to the injected acoustic signal injected.