We used to keep oil for years when I was in the oil biz but I don't know how many. There are special steel racks made for storing a drum like this and it might be a good thing to get one or at least build one.

The set-up is simple. The main thing to worry about is water. But oil is heavier than water, so the water falls to the bottom or, as we would say, drops out.

Lay the drum on its' side with a spigot in the filling hole so you can draw from it like a beer keg. There will be a small hole at the top that will also be sealed up with a small screw in plug.

Put something under the spigot end of the drum so it is tilted up a bit. In this way the other end of the drum is lower than the end you are pulling from.

All the water will fall to the lower end and stay there. When you are drawing off oil open the small hole at the top of the drum so it will flow and air will enter the drum to replace the oil you have removed. Otherwise air pressure will crush the drum.

But opening the hole to let air in also lets in water vapor which is in all air. The water will condense on the sides of the drum at night and drop out when it hits the oil.

The only danger is that someday the lower end of the drum might rust out, but this will take many years since while there may be water present there will be a lack of oxygen for it to react with.

Still, it is wise to have a pan under the lower end of the drum so you can see the very first drops of oil and or water when they do start to appear.

Some of our drums were in use for over 20 years. We never bought new ones because when they ran out we just went to the loading rack inside the refinery and filled them up again.