Saudi Arabia, the world\'s biggest oil exporter, will drill about seven test wells for shale gas this year, according to Oil Minister Ali Al Naimi. \"We know where the areas are,\" Al-Naimi said at a conference in Hong Kong yesterday, referring to the country\'s shale gas deposits. \"We have rough estimates of over 600 trillion cubic feet of unconventional and shale gas. So the potential is very huge and we plan to exploit it.\" Saudi Arabia is seeking to develop its natural gas resources to meet rising domestic energy demand. Saudi Arabian Oil Co., or Saudi Aramco, is searching for shale gas in the northwest of the country as it explores for unconventional resources such as sour gas in the oil-rich eastern region and in the Empty Quarter deserts, Senior Vice-President of Upstream Amin Nasser told a conference March 10 in Manama. The nation may hold as much as 645 trillion cubic feet of technically recoverable shale gas, the world\'s fifth-largest deposits, behind China, the US, Argentina and Mexico, according to estimates by Baker Hughes. The kingdom also has about 282.6 trillion cubic feet of proven conventional gas reserves, according to Aramco\'s 2011 annual report. Finding the necessary amount of water in the regions where Aramco is exploring will be difficult, Nasser said at the Manama conference. Shale gas is produced by a technique known as hydraulic fracturing, or fracking, in which massive amounts of water, chemicals and sand are blasted underground to free trapped hydrocarbons. Domestic gas prices are also too low to make developing the deposits economically feasible, Khalid Al Falih, Aramco\'s chief executive, said on January 14 in Dhahran, Saudi Arabia. The country sells the fuel locally at a subsidised price of 75 cents per million British thermal units. Gas traded on the New York Mercantile Exchange rose to $3.938 per million Btu yesterday, the highest level in 17 months. Time of oman