Firefighters attended a fire at the gas storage facility on Clayton Road off Newark Road in Lincoln.
Businesses in the area were evacuated as a precaution. The fire started just before midday.
A spokesperson for Lincolnshire Fire and Rescue said: “We’ve sent two crews from Lincoln North and one from Lincoln South.
“We were called to reports of a fire at a gas storage facility at around 11.50am.”
An eyewitness said: “Workers have been taking down the gas storage tank. They apparently gone through an oil seal which caught fire.
“I’ve spoken to the workers on site and they say it’s nothing to worry about as the tanks are empty and it would burn itself out.”
Firefighters are set to leave the scene shortly after 1.15pm. They said the fire was in a structure.
Nobody was injured, Lincolnshire Fire & Rescue added.