Stock Tank Oil

When people go out into the ground and try to find oil, they sometimes find it in big underground pools or reservoirs that are called "oil fields." To get the oil out and use it, workers use big pipes and machines to suck the oil up from the ground and store it in big containers called "stock tanks."

A stock tank is just like a giant swimming pool, but instead of holding water, it holds oil. The oil workers use special tools to measure how much oil is in the tank and make sure it doesn't overflow. Once the stock tank is full, they use big trucks to take the oil to a refinery, where it can be cleaned up and turned into things like gasoline that we put in our cars.

So that's what stock tank oil is: it's just oil that has been found underground, pumped up to the surface, and stored in a big container until it can be used for different things.