Petroleum Science and Technology, 26:1741–1756, 2008 Copyright © Taylor & Francis Group, LLC ISSN: 1091-6466 print/1532-2459 online DOI: 10.1080/10916460701287839 Surge Analysis of Multiphase Flow in a Gathering Manifold Y. Zurigat, 1 B. Jubran, 2 and L. Khezzar 3 1 The American University of Sharjah, Sharjah, UAE 2 Ryerson University, Toronto, Ontario, Canada 3 The Petroleum Institute, Abu Dhabi, United Arab Emirates Abstract: Analysis of pressure transients in multiphase flow in a real flow line upstream of a manifold in an oil-gathering station in the presence of slug flow is presented. The transient analysis is based on the solution of the partial differential equations governing the pressure transients using the method of characteristics. The analysis permitted the identification of pipe material and valve closure time com- binations that could lead to unacceptable pressure levels in the flow line and the combinations that represented a safe configuration. The results revealed that pressure surge could be responsible for a glass reinforced epoxy (GRE) pipe installed in one oil-gathering station. Keywords: manifold, multiphase flow, pipeline, pressure surge, single-phase flow 1. INTRODUCTION In many oilfields, oil production is accompanied by water and gas pro- duction that needs to be transported over long distances via a network of pipelines. While the design of single-phase flow pipeline is well established, the multiphase flow poses a problem for designers and operators alike. To date, the multiphase flow behavior in transport systems is still not fully understood, and the prediction tools are highly empirical, which limits the predictions to a limited range of parameter space. Hence, unexpected flow conditions may arise that could lead to accidents such as rupture, leakage, and fires. As a safety measure, emergency shut-off control valves (ESCV) are used to mitigate the risks associated with unexpected flow conditions or operation-related causes. The closing of ESCV may or may not cause pressure surge depending on the flow conditions. This is a classical problem Address correspondence to Yousef Zurigat, The University of Jordan, Amman 11941, Jordan. E-mail: zurigat@ju.edu.jo 1741