Irving Oil is now receiving one trainload a week of crude oil from North Dakota, according to an American energy analyst.
However, that has not been confirmed by the company.
"It is gold to a refinery," says Bob Vander Valk, an American oil industry analyst.
Vander Valk says the oil from the Bakken Field of North Dakota and Montana requires little refining.
"It is such a high quality the oil could be actually burned in a diesel engine without being refined. It's that good," he said.
Vander Valk says Irving can buy the oil at a considerable discount because there is no pipeline to carry it to markets.
He claims that starting this month, Irving Oil began moving one train a week — between 90,000 and 100,000 barrels of oil from North Dakota to Saint John.
"If you can buy it for a $15 discount which would make it about $80 a barrel you're still saving yourself $35 a barrel," Vander Valk said.
There has been a media report the company is trying to secure a supply of Alberta oil.
When Irving Oil was asked by CBC News if the oil arriving by rail will only be coming from North Dakota, it responded by saying it has refined crude from areas around the world for decades and welcomes crude from Alberta.
The company is building a rail terminal off Bayside Drive in east Saint John, which has been criticized by environmentalists, who say it's being built without doing an environmental impact assessment.
The site is bustling with activity — piping and underground infrastructure being installed alongside a set of four newly laid tracks.
Irving Oil has said the new terminal will improve its "ability to receive and deliver product."