Well failures in May and July 2017 resulted in removal of two Xmas Trees from operation and significant lost production. Recompletion was sanctioned, with a stretch target of production reinstatement within an opportunistic 61 day rig window in Q4 2017. Due to ambitious schedule targets rig intake, equipment preparation, procedure development and risk assessment were all placed on the critical path. Due to available equipment configuration bore depressurisation cycles required direction of fluids to the asset, increasing rig and asset simultaneous operations.
A one team approach was used, with proactive engagement including asset, drilling, subsea and multiple suppliers. Process modelling of the planned operations provided an accurate execution framework for work to be performed within. Story board presentation of the key steps allowed optimization of the activity sequence, and clear basis for risk assessment. Changes to plan during execution were controlled through rigorous use of procedure updates, management of change and risk assessment. The operation also utilised an ROV piloted from shore to optimise offshore headcount.
The workover was safely completed in December 2017, re-instating production from one of the wells and allowing onshore hardware investigation to be undertaken. The failed equipment was available for testing within a week of its recovery. Production was restarted within 5 months of failure. Around 100 lessons were captured during the work, to be used as basis for further well recompletion in 2018. This presentation will describe and explain how this success was achieved.