The Tarim Basin is believed to contain large potential reserves of petroleum and natural gas.

China, which pumps 2.7 million barrels of oil a day, is the world's fifth-largest producer, with potential undiscovered reserves approaching those of Kuwait.

"Maybe it's only a routine investigation of potential reserves in case of crisis."

The Kurdistan region's economy is dominated by the oil industry (with potential reserves of around 45 billion barrels), agriculture and tourism.

Exxon blamed "sluggish product demand, low oil and natural gas prices, and sharply limited access to the nation's best potential reserves."

However, developing this potential reserve is currently not cost-effective due to technological limitations coupled with fluctuations in world oil prices.

Estimates of potential reserves, he added, run as high as 5 trillion cubic feet.

Britain too, it seems, is sitting on huge potential reserves of shale gas, which could supply us with cheap energy for centuries to come.

However, it is not unusual for existing permissions or potential new reserves of aggregates to be found in such areas.

Maniguin has a potential reserve of 28 million barrels to 250 mmbbls.