Detection of Localized Deterioration Distributed along Single Pipelines by Reconstructive MOC Analysis

Abstract

The detection of localized deterioration that is distributed along pipelines, including wall thickness reduction caused by large scale corrosion, is essential for targeted pipeline maintenance and the prevention of pipe failure. This paper proposes a novel technique for the detection of distributed deterioration along a pipeline by estimating the distribution of pipeline properties using a measured pressure transient trace. The proposed technique is referred to as reconstructive method of characteristics (MOC) analysis, and it is an inverse process of the traditional forward MOC calculation. The reconstructive MOC analysis reconstructs the MOC grid and estimates the pipe parameters, such as impedance and wave speed, reach by reach from downstream to upstream. Numerical simulations are performed on a pipeline with three pipe sections of impedance changes. These deteriorated sections are accurately detected and located by using the new technique. Experimental verification is also performed by successfully detecting a section of pipe with a thinner wall thickness in a single pipeline.