I did not expect that there was such a big dip in the 80's. The oil crisis was in the 70s, right?

Here are some factoids from there:

[In] large oil fields, the natural pressure of the reservoir forces the oil to the surface. But as more and more oil is pumped out, the only way to keep the pressure up is to inject water back into the reservoir.

After a while, this starts to damage the reservoir... the water starts to contaminate the oil. Author Paul Roberts found that at Ghawar, the amount of water mixed in with the oil is now 30%. That's a dangerously high level.

[Matthew Simmons found] that the water-injection technique that's keeping Ghawar on life support is also being used on every other major oilfield in Saudi Arabia - the fields that supply 10% of the world's oil right now.

[Look again] at that chart of Saudi oil production. It's gone up a lot since 2001. But Saudi oil exports have stayed flat! The Saudis need oil to fuel their growing economy.

[The] increase that started in 2001 was pretty much over by 2003. But since 2003, the number of drilling rigs in Saudi Arabia has tripled. Triple the drilling, triple the output, you'd think. But no...all that new drilling, and the country is still generating between 9-10 million barrels a day. So they've had to triple the number of wells just to keep running in place!