Flow induced vibration (FIV) research of oil and gas process piping system

Abstract

Piping systems in crude oil production facilities tend to handle high pressure and high velocity flowing fluid at certain flow rate limit resulted in generation of turbulence flow. This turbulence can generate high levels of broad band kinetic energy which can propagate through the system. Even though the energy is distributed across a wide frequency range, most of the excitation is concentrated at low frequency (typically below 100 Hz); the lower the frequency, the higher the level of excitation from turbulence. This leads to excitation of the low frequency vibration modes of the pipe work, in many cases causing visible motion of the pipe and, in some cases, the pipe supports, and this phenomenon is called Flow induced vibration (FIV) and if excessive can result in fatigue failure. This objective of the paper is to identify potential sources of FIV on piping by predicting the Likelihood of failure (LOF) and advising on the necessity for system modifications to minimize or eliminate any FIV induced piping or line failure from Flow Induced Turbulence. These are done by conducting a FIV assessment for piping systems in oil production facilities which are potentially affected by vibration due to both process conditions and mechanically induced pipework vibration. Another scope of this paper is to apply the recommendation action required in order to reduce the likelihood of failure by changing pipe diameter and/or wall thickness by looking at the fluid structure interaction (FSI). By changing the outer diameter and the wall thickness of the pipe, the formation of the excitation in flow regime and the presence of the critical flow disturbance will decrease. These changes are able to reduce the formation of FIV thus increasing the lifespan of the piping system.