Maybe if your 'oil tank' was an oil filled transformer there would be requirements in the NEC. Probably not the case...
Has anyone heard of a code that an electric panel cannot be within 5' of an oil tank? I am in NH. Thanks
Is there any requirements of a having a panel close to an oil filled transformer? a quick search of 408 didn't turn up anything
As far as an oil tank goes, I think it would depend upon the flash point of the oil, if under 100? it would be a article 500 location, if it produces a flammable vapor under normal operating conditions, which I don't think most oil will, maybe used oil with gas mixed in might, but that would be per case call.
If it does then 515 would have to be followed.