Subsea System Design for the HPHT Kristin Field Development. Thermal and Pressure Loads.

摘要

The HPHT field Kristin is located 16 km south west of the ?sgard field in the North Sea. The reservo ir has a temperature of 170°C and a pressure of 911 barg. The field will be produced by pressure depletion from four subsea templates tied back to a dedicated floater. Kristin is the first subsea HPHT field development. First production will be autumn 2005. The production lines, flexible risers and the topside process are protected by three separate pressure protection systems including a subsea HIPPS system. Direct electrical heating will be installed for the production line as the main hydrate control measure. For the design of the subsea system and the operational procedures for the system, special attention must be given to the high temperature and pressure. The high and low temperatures imposed on the production system by the producing fluid during normal production, shutins, restarts and operational/system failures make the design challenging. This paper will give an overview of the flow assurance work. The design and operational consequences of the high pressure and temperature loads on the wells, template piping, production lines, electrical cable and flexible riser are presented.