“Axial vibration” caused failure of compressor – ExxonMobil

Flaring offshore Guyana

…currently being reassembled

Oil giant ExxonMobil has attributed the vibration of the axial rotor to the failure of its compressor, which has since been shipped to Germany and which had led to the company’s controversial routine flaring offshore Guyana.

In an update on Saturday, Exxon’s Government and Public Affairs Advisor Janelle Persaud explained that the technical experts at the MAN Energy Solutions workshop in Germany are presently reassembling the flash gas compressor.
She revealed that from their detailed examination of the compressor, they found that an irregular axial vibration of the rotor in the compressor caused the technical issue Liza Destiny experienced on January 27.
“The resulting vibration within the compressor was the cause of the mechanical seal failure initially reported… As previously indicated, reinstatement could take up to eight weeks,” Persaud explained.

“A key component of the assembly, the discharge silencer, which was transported to Germany separately based on the disassembly sequence on the FPSO, is under evaluation and assessment to determine the scope of repairs required.”
According to Persaud, the workshop has completed the adjustment of all the seals for the suction and are assembling and realigning the seals and the bearings. A comprehensive root cause analysis is also being conducted.
The governance and public affairs advisor also noted that Exxon “will take full action to incorporate lessons learned for the FPSOs employed in future projects, including Liza Phase 2 and Payara.”
Late in January, Esso Exploration & Production Guyana Limited (EEPGL) had announced that it was experiencing technical problems with the seal on Liza Destiny’s flash gas compressor. The problem resulted in Exxon having to reduce its production and also conduct routine flaring.
It was subsequently revealed that Exxon had been flaring 16 million cubic feet of gas per day, an increase from the volume of flaring the company conducted last year which reportedly ranged between 12 and 15 million cubic feet.
It is a situation that Exxon executives have said no one is happy with, even as they work along with the regulatory agencies. Additionally, it was announced that Exxon is currently producing around 120,000 barrels of oil per day (bpd). Before the flaring, production was at 130,000 bpd.

EPA
While some have called for the Environmental Protection Agency (EPA) to act, their hands are, in fact, tied. At a recent press conference, Vice President Bharrat Jagdeo had pointed out that Exxon is limited to flaring 14 billion cubic feet of gas.
This is per the approved Environmental Impact Assessment (EIA), which means that according to calculations, Exxon wouldn’t reach that flaring ceiling at current levels until the end of April 2021. Nevertheless, he had described the company’s current routine flaring as unacceptable.
However, Jagdeo had noted that by June of 2022, when the Liza 1 permit expires and has to be renewed, Exxon will have to submit to the inclusion of fines in the Liza 1 permit that is similar to what is obtained in the Payara permit.
Additionally, President of the Guyana Oil and Gas Energy Chamber (GOGEC) Manniram Prashad has since described calls from former EPA Director, Dr Vincent Adams for Exxon’s operations to be terminated due to the flaring as “unnecessarily extreme”.
Back in December on the oil company’s first year anniversary since commencing production in 2019, Routledge had expressed disappointment at the equipment issues they experienced and had also assured that routine flaring would not be employed. (G3)