Summary
The gas flowrates at a North Sea offshore installation had changed significantly from the original design with the asset becoming
gas deficient. As a result, the reliability of the gas compression train had reduced and contributed to several unplanned shutdowns.
We were engaged to provide engineering and commissioning expertise to redevelop the current control philosophy from discharge pressure control to suction pressure control.
Our Scope
Create a process control and operating philosophy for the gas compression facilities.
HAZOP facilitation and provision of a HAZOP chairperson to identify and assess hazards and risks associated with the change of control philosophy.
Specification of the required control and graphic modifications in compliance with the requirements of the process and control philosophy.
Management of the ICSS and compressor system suppliers, including project delivery, document approval, and FAT acceptance.
Development of the commissioning strategy and associated procedures, ensuring the commissioning boundaries are suitable whilst ensuring the operational impact and production downtime are minimised.
Act as the offshore commissioning authority with overall responsibility for the safe and effective delivery of the project.
Result
During a planned asset shutdown, the modifications required to change the control philosophy of the gas compression train from discharge to suction pressure control were successfully installed and tested.
The compressors were successfully started first time. Clear communication and teamwork between the commissioning and operations personnel was instrumental in this achievement.
Following start-up, controller tuning was successfully completed to optimise the gas compressor, gas lift, and gas export systems.