1 Copyright © 2010 by ASME Proceedings of the 14 th International Heat Transfer Conference IHTC-14 August 8-13, 2010, Washington D.C., USA DRAFT IHTC14-22462 TEMPERATURE FIELD PREDICTION OF A MULTILAYERED COMPOSITE PIPELINE BASED ON THE PARTICLE FILTER METHOD Flavio L. V. Vianna Department of Subsea Technology Petrobras Research and Development Center Rio de Janeiro, RJ, Brazil Helcio R. B. Orlande Department of Mechanical Engineering COPPE, Federal University of Rio de Janeiro Rio de Janeiro, RJ, Brazil George S. Dulikravich Department of Mechanical and Materials Engineering Florida International University Miami, Florida, USA ABSTRACT Thermal management of subsea oil production systems in deep water environments is one of the main issues for petroleum exploitation operations. Thermal monitoring is crucial to avoid and control the formation of solid deposits, which in adverse operating conditions can result in blockages inside the production systems and consequently incur large financial losses. This paper aims to demonstrate the robustness of a Bayesian approach for accurate estimation of the produced fluid temperature field in a typical multilayered composite pipeline. The physical problem consists of a pipeline represented by a circular domain filled by a stagnant fluid (petroleum) with temperature dependent thermal properties, which is bounded by a multilayered composite pipe wall. The mathematical model governing the heat conduction problem in the multilayered wall and in the stagnant fluid was solved with the finite volume method. The Particle Filter method was used for the solution of the inverse transient problem involving the prediction of the temperature field in the medium, from limited temperature data available at one single location in the pipeline composite wall. The aim of this method is to represent the required posterior density function by a set of random samples with associated weights, and to compute the estimates based on these samples and weights. Results are presented in this paper by taking into account uncertainties in the state evolution and measurement models. Simulated temperature data is used in the inverse analysis for typical conditions observed during production shutdown periods. INTRODUCTION Flow assurance in the petroleum industry is one of the challenges of the development of subsea field layouts due to a combination of factors, involving, among others, the dynamic nature of the produced fluids, high internal hydrostatic pressures and low external environmental temperatures [1]. In general cases, these subsea systems are designed to transport the produced fluids through the different equipments without experiencing significant heat losses to the environment [2]. Thermal management of these equipments and pipeline systems are of great importance for the prediction and prevention of solid deposits [3]. The most common deposits are waxes and hydrates (depicted in figure 1), which precipitate at certain critical combinations of pressure and temperature [4]. Typical thermal analyses make use of direct problem solutions to compute the temperature profile along the pipeline and represent one of the most important steps in the subsea layout design. Thermal analyses include both steady-state and transient studies for the different stages of the field’s lifetime. The thermal design determines the best configuration to maintain the produced fluid temperature above a minimum value, thus avoiding the formation of wax or hydrates. In steady state operations the petroleum temperature decreases as it flows along the pipeline, due to heat transfer through its walls. This steady state temperature profile is used to identify the flow rates and the insulation systems that are needed to keep the subsea system above the critical temperature during the production [5-6]. For cases with long tie-backs, pipelines with efficient thermal insulations are required, such as the so-called pipe-in-pipe systems [7,8].