LONDON, April 19 (Reuters) - Drilling for oil has begun in Sudan's troubled Darfur region after preliminary studies showed there were abundant quantities of oil, a spokesman for the country's Energy Ministry said.

Sudan's main oilfields are in the south and disputes over oil drew out negotiations to end 20 years of civil war.

"The drilling was undertaken on the basis of the geological studies and surveys which proved the presence of oil in abundant quantities in Darfur," Mohamed Siddig, a spokesman for Sudan's Ministry of Energy and Mining, told Reuters by phone from Sudan.

A peace deal signed in January revived interest in Sudan's potential oil reserves but analysts say the conflict in Darfur, where tens of thousands have been killed and at least 2 million driven from their homes, has scared off investors.

Siddig said the ABCO consortium -- in which Swiss company Cliveden owns a 37 percent share -- owned the rights to the field.

Work on the first oil well, southwest of El-Fasher in North Darfur State, is underway.

Sudan began exporting oil in 1998 and exports around 300,000 barrels a day, which is set to rise to 500,000 barrels by August.