Oil major ExxonMobil has revealed its disappointment with the performance of the Liza Destiny FPSO, operating on the Liza field off Guyana, following technical issues, which forced it to reduce output to a minimum.
Offshore Energy has reported on this issue several times since the problems started in January 2021.
The technical issue was related to a seal on the gas compressor on the SBM Offshore-owned FPSO Liza Destiny, prompting ExxonMobil to temporarily increase the flare above pilot levels to maintain safe operations.
ExxonMobil, SBM Offshore, and MAN Energy Solutions have been working to fix the problem since then.
By the end of March, teams of experts were making final preparations for the start-up of the flash gas compressor on the Liza Destiny FPSO, in order to restore the flare to background levels.
But the repairs were still not completed by early April. Instead, the team onboard the FPSO initiated a comprehensive three-phase testing programme.
ExxonMobil said that the final stage of testing would take place this week after the removal of temporary instrumentation.
In an update on Wednesday, ExxonMobil revealed another problem that had come up: “As we conducted the final testing phase of the reinstalled flash gas compressor and other components of the system on the Liza Destiny FPSO, we encountered an additional problem with the discharge silencer”.
A team from SBM Offshore, MAN Energy Solutions, and ExxonMobil are on site to assess repairs, with support from engineering experts in Europe and the USA.
The company added it had reduced production to a minimum level that mitigates the formation of hydrates in subsea systems, maintains gas injection and fuel gas to the power generators, and minimizes flare.
Relevant government agencies have been notified and ExxonMobil is continuing to work with officials to determine the next best steps.
The company further said: “ExxonMobil Guyana is extremely disappointed by the design issues and continued underperformance of this unit and will be working with the equipment manufacturer MAN Energy Solutions and the vessel’s operator SBM to rectify the situation”.
“This performance is below ExxonMobil’s global expectations for reliability”, the oil major concluded.
The concept design for the Liza Phase 1 development project features the Liza Destiny FPSO moored 190 kilometres offshore Guyana, and four subsea drill centres supporting 17 wells.