This paper details the successful first implementation of closed-loop Managed Pressure Drilling (MPD) technology offshore Australia, on a 6th generation semi-submersible rig.
The paper covers the process of achieving safety case acceptance to implement MPD technology from the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA), the government regulatory authority.
The paper describes the project concept design phase, including a Drill Well on Simulator (DWOS) exercise, which was completed to confirm MPD techniques would mitigate problems experienced on conventionally drilled offset wells.
The MPD risk assessments completed included HAZID / BOWTIE / HAZOP / FEA studies which were included in the safety case formal safety assessment that was submitted to NOPSEMA. In parallel the Well Operations Management Plan was submitted, detailing the planned MPD methodology. The detailed Well Engineering scope including the MPD Programme, Operational and Contingency Procedures and Commissioning Process was developed to form a Joint Operations Manual.
Four levels of project specific MPD training were developed, reviewed, accepted and monitored by NOPSEMA, including classroom based and rig site practical training.
Post MPD system installation in Singapore, the System Integrity Testing was successfully completed offshore Australia.
Lastly the paper details MPD operations on the first well including the effective use of MPD well control, dynamic MPD FIT, LOT and Pore Pressure testing and establishing the high formation temperature effects on drilling mud density. The closed-loop MPD system allowed the riser deployed sections to be drilled using a statically underbalanced mud system and confirmed the improved capability and flexibility in terms of detection and controllability during mud loss events.