Iran has discovered \"one of the biggest natural gas fields in the Middle East\", with reserves comparable to those of the South Pars field, Mehr reported, citing an industry official. The gas was found in south-western Khuzestan province at a deposit already known to contain crude oil, said Mahmoud Mohaddes, co-director for exploration at National Iranian Oil Co, according to the state-run news agency. A 5,000-metre well will be drilled \"soon\" to collect further information, he said. South Pars, the world\'s largest proved gas deposit, is shared between Iran and Qatar. Iran holds the world\'s second-largest gas reserves, with 29.6 trillion cubic metres, according to the BP Statistical Review of World Energy in June 2011. Russia has the biggest reserves of the fuel, BP data show.