Optimization of Flow Assurance Applications Through Life-of-Field: An Integrated Approach to Production Engineering and Chemical Management Across Gulf of Mexico Deepwater Assets

Abstract

Abstract This paper outlines lessons learned in flow assurance and chemical application strategies across the operator's deepwater assets in order to maximize production while minimizing OPEX, and provides a basis for potential improvements in flow assurance strategies and chemical application going-forward with the integration of a larger engineering team comprising subsurface, major projects, production operations, flow assurance and production chemistry personnel. During the initial phases of field development a large amount of analysis is undertaken to determine potential flow assurance risks over the life of the field, including bottomhole sampling to determine the potential for wax, asphaltenes, scaling, and hydrates. This initial testing is used as a basis for effective flow assurance chemical applications throughout the life of the field. Once wells are brought online and production declines (along with increasing watercut), well characteristics will change and the initial testing may require revalidation. The field development plan and infrastructure will dictate the viability of certain flow assurance strategies, particularly around startup and shutdown. In certain cases the lack of infrastructure limits the tools available for operators and in other cases the production profile of the field will determine the viability of certain operations. As a result, effective chemical application and selection is crucial and plays a pivotal part in continuous production with minimal requirements for well intervention and/or infrastructure. An effective flow assurance strategy begins with accurate data collection, lab analysis and the integration of Sub-Surface, Production Engineering, Flow Assurance and Production Chemistry stakeholders. An early lab analysis should provide a basis for a flow assurance strategy, but this needs to be revised over time. Field development and infrastructure might provide all the tools required for effective flow assurance, but operations may be inhibited by changes in production rates. While data can be used to set initial dosage rates for chemicals, their effectiveness needs to be monitored over the life of field. Real-time data should be used as a tool for monitoring the effectiveness of flow assurance chemicals. To ensure the asset is not compromised by flow assurance issues, alarms should be set to automatically alert operators when nearing threshold values for hydrate formation, asphaltene instability, and wax appearance. With the use of real-time data, online monitoring, and accurate production information an effective chemical optimization strategy can be implemented. This integrates subsea data with flowline bathymetry and pressure/temperature profiles to provide engineering and operations a real-time snapshot of conditions from downhole to topsides. Based on this data, adjustments to flow assurance chemical dose rates can be optimized to maximize asset integrity while minimizing operating expenditures. Furthermore, it provides a more accurate analysis on potential flow assurance issues around transient startup and shutdown conditions.