Cold Flow: New Operational Scheme

Objectives/Scope Hydrates and paraffins are formed at high pressure, low temperature, conditions encountered on most of our offshore developments. Line plugging due to hydrates or paraffins are undesirable outcomes which must be avoided. One of the main constraints of offshore development is therefore the management of hydrates and wax in the production line. A new design philosophy has nevertheless been considered and implemented, pushing limits forward and challenging all knowledges acquired over the last decades on Flow Assurance. Methods, Procedures, Process This new concept – "Cold Flow" – consists of the installation of a single and non-insulated line, capitalizing on the improvement of the know-how on hydrates formation and paraffins deposition mechanisms. This new concept combines four major innovations: – The mastering of the prediction of paraffin deposition using software The current design approach of thermal insulation of offshore field consists in staying free from hydrates crystallization thermodynamic and paraffins deposition regions in normal operations, and sometimes during transient operations (restart, Etc.). Such design philosophy usually imposes the installation of "heavy" subsea architectures (loop for pigging, stringent thermal specification, Etc.) and the implementation of "complex" operating procedures, therefore impacting CAPEX, OPEX and production shortfalls. The decision to relax the production line thermal insulation, in total opposition of usual design approach, is supported by major improvements in the understanding of hydrate crystallization mechanisms and paraffins deposition over the last decades. On hydrates and paraffins management perspective. Results, Observations, Conclusions The use of the SAPL (Subsea pig launcher) to control paraffins in the line, combined with the development of this Flow Assurance concept, allows the use of a new operational scheme for the development of future fields. Novel/Additive Information In brief, in the future, more inventive and aggressive designs combining those creative blocks will be proposed, with the main objective of unlocking reserves and projects.