The other weekend I went diving up at Yanbu. Yanbu is just two hours north of where I live. Yanbu is home to the Aramco Yanbu Oil Refinery. Perhaps you've heard of it? This little operation in the middle of no-where Saudi Arabia can produce up to 4.5 million barrels of oil a day. I repeat. 4.5 million. barrels. A day. Check out the nice brown haze that floats above the plant.
If you're curious... the process of oil refining is explained here