Oil reserves in Libya are the largest in Africa and the ninth largest in the world with 41.5 billion barrels (6.60×10^9 m3) as of 2007. Oil production was 1.8 million barrels per day (290×10^3 m3/d) as of 2006, giving Libya 63 years of reserves at current production rates if no new reserves were to be found. Libya is considered a highly attractive oil area due to its low cost of oil production (as low as $1 per barrel at some fields), and proximity to European markets. Libya would like to increase production from 1.8 Mbbl/d (290×10^3 m3/d) in 2006 to 3 Mbbl/d (480×10^3 m3/d) by 2010–13 but with existing oil fields undergoing a 7–8% decline rate, Libya's challenge is maintaining production at mature fields, while finding and developing new oil fields. Most of Libya remains unexplored as a result of past sanctions and disagreements with foreign oil companies.
And at another Wikipedia link http://en.wikipedia.org/wiki/Economy_of_Libya we find that in fact, significantly large new oil reserves have been discovered there since 1997, with estimated cost of production to be only $1 per barrel.
Bear in mind that light crudes are more easily refined into diesel and petrol and also low in sulphur (sweet), making them cleaner to burn. Light crudes yield more diesel per barrel than heavier crudes. Saudi Arabia, the de facto custodian of Opec’s spare capacity, will “meet any shortage,” oil minister Ali Naimi said this week. But its oil is a poor substitute for Libya’s. Arab Light, the leading Saudi oil by volume, is a relatively high 1.8 percent sulphur and heavier, so more difficult to refine into light products such as diesel. Growth trends in global diesel demand combined with tightening environmental regulations will put increased pressure on demand and prices for light sweet crudes.