Development of a Double Beam Model for Predicting Intrusion in Pipelines

Abstract

This paper examines pipeline safety and develops a mathematical model for predicting illegal intrusion. The model idealizes a typical pipeline structure as a pipe-in-pipe double beam, consisting of the process pipe encased in a larger diameter outer carrier pipe resting on an elastic soil foundation. Intrusion is considered to consist of hammering and cutting activities on the casing pipe which transmits shock motion to the process pipe. From the solution feedback control algorithms have been proposed for designing surveillance instruments which assist in mitigating the problem of illegal intrusion for harvesting of crude oil. A point sensor was used to simulate the response to intrusive hammering action induced on the casing pipe in a 2 m segment of the process pipe in an example. Sensor was conFigureured to measure displacement response at intervals of 2 seconds at (0.00, 0.06, 0.12,..., 2.00) m sampling points. The displacements indicated within the model assumption of zero damping, were 4.62 x 10-4 m and 4.24 x 10-4 m at the left and right hand anchors. A deflection of around-2.67 x 10-4 m was obtained at 0.94 m.