Iran has begun production of 28 million cubic metres a-day (cm/d) of gas from phase 21 of its South Pars offshore gas field.

With the added output, gas production from South Pars increased to 515 million cm/d, said Alireza Ebadi, operator of phases 20 and 21, in comments reported by Shana, the news agency affiliated with Iran’s petroleum ministry.

Iran hopes to increase gas production from South Pars to 530 million cm/d by March 2017, with total gas output expected to reach around 830 million cm/d.

Gas extracted from platform 21 is sent to refineries associated with phases 20 and 21, to get sweetened, before being sent to the national trunk line.

Phases 20 and 21 have the capacity to extract 56 million cm/d of sour gas, which will be sent to sweetening stations three and four expected to come online in early 2017 - adding 50 million cm/d of sweet gas to the nationwide network.

In November, French energy firm Total and China National Petroleum Corporation signed a preliminary agreement worth $4.8bn with state-run National Iranian Oil Company to develop phase 11 of South Pars.

The deal marked the first agreement between the NIOC and a major international oil company, since nuclear-related sanctions were lifted in January 2016.

The South Pars gas field - which covers an area of 9,700 square kilometres is the world’s largest. Around 3,700 square km of the field falls under Iran’s territorial waters, while the remaining - called North Dome - belong to Qatar.

The gas field is estimated to hold 18 billion barrels of condensate, which is approximately eight per cent of the global gas reserves.