A Real Case of Integrated Multiphase Gathering System Optimization through a Flow Assurance Workflow

Abstract

Production optimization is one of the most complex and multi-disciplinary task in the Oil & Gas industry. It involves the surface asset during all its production life and requires a continuous improvement process.Integrated optimization of surface asset, including both gathering facilities and process plant, is a difficult goal to be achieved due to the complexity of such systems and the presence of several variables, uncertainties and operational constraints.Technology improvements have enabled a widespread use of integrated simulation models for a better asset management according with actual field data.Production department team of ENI E&P has developed a tool which maximizes production integrating gathering system simulation with process plant simulation. The global optimum is reached through a powerful genetic algorithm that, according to system constraints, allows to control different variables in a simultaneous way.In fact, steady state simulation environments could bring to unstable field configuration. As a consequence, an updated operative workflow for fluid-dynamic module is needed. This workflow supports the process to select optimized solutions that do not have any criticalities during operation and asset variables upset. This implies that unstable solution are discarded among the investigated ones. Therefore, the obtained maximized production configuration is the global optimum solution (robustness of algorithm) as well as the most stable (fluid-dynamically).Finally, multiphase transient code analysis allows to understand actual flow regime and, if necessary, to identify mitigative actions for management's improvement of investigated asset.The integrated workflow has been applied to a real case study. This presents technical contributions of this work for definition of field potential, production optimization, de-bottlenecking activities, asset management.