Shell has started conducting three days of planned flaring at Mossmorran in Fife.
The company's natural gas liquids plant began flaring at 10:00 BST on Saturday and it will last for 72 hours.
Shell Fife NGL plant shares the Mossmorran site with ExxonMobil.
James Glen, Mossmorran Action Group chairman, said he was bracing himself for noise but expected Shell's flaring to make less of an impact than Exxonmobil's.
Mr Glen told the BBC Scotland news website: "Shell is less impactful as it is more proactive on its repair and maintenance schedules so it has more stable operations and less instances of flaring.
"It's Exxonmobil's poor management of the site which causes them to have many more unscheduled flaring instances.
"Shell does share Exxonmobil's equipment sometimes so if it uses the main flare stick then we will have noise."
Stuart Neill, external affairs manager for ExxonMobil said: "We were disappointed that the Mossmorran Action Group (MAG) refused our recent invitation to meet in person with our plant management team, and to see our operations first-hand.
"Our invitation remains open. We are keen to improve MAG's knowledge and understanding of the facts regarding our operations and multi-million pound maintenance programme."
A Shell Fife NGL spokeswoman, said: "This weekend we will start our annual 'turnaround' at the Shell Fife NGL plant, when we will reduce production over a 15-day period in order to carry out planned investment and maintenance on the plant.
"As part of this turnaround, I would like to notify the local community of planned, intermittent use of the Fife NGL elevated flare during a period of 72 hours, beginning 10:00 on Saturday, 10 August.
"We must use the flare to empty the pipes and vessels on module 3, which then enables us to complete testing on our safety systems and maintenance on the module's safety-critical valves.
"The plant preparation will be phased in order to minimise the flaring rates as far as possible, including by use of our ground flares."