Economical field development strategy often implies tie-in of subsea satellite fields to nearby host installations. This leads to a whole new set of benefits and challenges considering design and material selection, production volumes and limitations, company strategies, holistic management and multi-disciplinary approaches. Operation of complex systems with multiple fluid streams demands a broader understanding of the chemical processes taking place when different fluids are mixed. Typical challenges include mineral scale and "soft scale" deposits. To ensure optimum production and provide flow assurance through chemical management, proper monitoring is essential. Guidelines and best practices are even more required if the tie-in to the host includes several operators and service companies.
Over the years, the Statoil operated Oseberg asset has through close cooperation with its chemical supplier M-I SWACO systematically improved the sampling and analysis procedures to strengthen the quality of data used in system monitoring. The supplier needs to have a strong focus on flow assurance related to chemical management and provide a range of onshore and offshore monitoring techniques and tools.
Challenges from the North Sea Oseberg Field Centre installation with subsea tie-ins have been discussed. Laboratory and field data from bottle tests, chemical analysis, preservation techniques and scaling potential simulations are presented. The results have been used to plan for side stream tests, develop guidelines for early identification of flow assurance challenges, sampling and monitoring of complex fluid systems and chemical management to avoid process upsets and production losses.