TEHRAN June 30 (Shana)-- Construction of South Pars gas fields phases 20&21 gas ,processing installations has made a 60% progress, the operator of 20&21 phases Gholamhosain Garshasbi, said. Speaking to Shana, Garshasbi noted that construction of onshore installations of the two phases is progressing 1.5 percent each month on average, the highest ...