Purifies the crude oil coming in to be useful for Gasoline, Diesel, etc.
A crude oil refinery is a factory. The factory takes the crude oil, and turns it into useful products, like gasoline.
Refinery
by refining crude oil
An oil refinery
After crude oil is removed from the ground, it is sent to a refinery by pipeline, ship, or barge. At a refinery, different parts of the crude oil are separated into usable petroleum products.
at the refinery
Refinery
Gasoline is refined from crude oil at a refinery.
They are refined in a refinery from crude oil.
there are three crude oil refineries in Nigeria, portharcourt refinery, warri refinery & kaduna refinery
somewhere close to the ocean because tankers come to the refinery to pick up the crude oil in the refinery
That would be a "refinery".