TEHRAN, Apr. 07 (MNA) – Manager of 9th refinery of South Pars Gas Field Seyyed Mohammad Mehdi Hashemi said that gas production volume in this refinery (phase 12 of South Pars) increased 21 percent in the second half of the last year (from Sept. 22, 2017 to March 20, 2018) as compared to the first half of the same period.