Middle East Oil Resources
There is a very strong correlation between distribution of the Shias in the Middle East and the Caucasus and the those of oil and natural gas resources. This is true from the Republic of Azerbaijan and the Caspian Sea to the Persian Gulf.
Even the Saudi oil deposits are primarily found under the Shia-inhabited districts of Hasa, Qatif, and Hofuf (reconfigured into "Eastern Province" in modern Saudi Arabia), and the Saudi continental shelf extending from there into the Gulf .
The same is likewise true of Iraq. Three-quarters of all oil deposits in that state are within the Shia-inhabited areas, with the rest largely in the Kurdish north.
Source: The Gulf/2000 Project at the School of International and Public Affairs of Columbia University