The Dictators Handbook is a great book that talks about how natural resources can lead to autocracy a lot of times, because leaders can extract resources, sell them to get money/power and not give a damn about individuals. Countries that have fewer resources tend to need support from a larger selectorate and tend to (not always) lead to more democratic societies.

So that does go with what you said (I don't know their oil history, but I assume they build a society that was culturally western European before they discovered and started extracting oil resources).