Synthetic liquid fuel production from coal is very expensive, but the gap between it's cost and 'natural' oil is narrowing daily.
In fact it is now a lot cheaper than the current oil prices. The problem is pollution. If the most pessimistic projection is accurate they have 30 years to extract a clean cheap fuel from coal.
Q: What countries have the biggest coal reserves?
A: All the western powers as well as places like China have up to 300 years supply.
Q: What coal reserves do the current oil producers in the middle east have?
A: None.