Active Heating for Life of Field Flow Assurance

摘要

Development of thermal management strategies in the design of subsea oil and gas production systems iscritical for prevention of solids deposition such as hydrates and wax formation during turndown andshutdown scenarios. Passive insulation provides no control of fluid temperature and forces the operatorto depressurise the pipeline following a shutdown and ‘no touch’ period i.e. time after which the fluid fallsbelow the hydrate temperature. For deep water and ultra-deep water applications this approach would beineffective as the large riser static head would prevent the pipeline pressure being reduced below thehydrate formation pressure. In these cases there is a requirement for active heating or dead oil flushing.Active heating provides the capability to monitor and control the fluid temperature during start up,shutdown and turndown operations. Several electric and hot fluid circulation active heating systems arein operation as part of bundle or pipe in pipe systems.This paper will review current active heating system designs in pipe-in-pipe (PiP) and bundle systems.In light of recent projects that have employed hot fluid circulation systems, the flow assurance challengesand subsequent design to ensure complete system functionality across the life of field will also bediscussed.