National Iranian Oil Company (NIOC) has signed a $5bn deal with the local Petropars to complete phase 11 of the South Pars gas field development, replacing a previous deal with China National Petroleum Corporation (CNPC), according to local state media.

Petropars is already working on phases 12 and 19 of the development and is revamping phase 1.

Phase 11 of the development of the world’s largest known gas field covers the installation of two wellhead platforms, drilling 24 development wells and the construction of an onshore gas treatment plant.

The phase is designed to produce 2 billion cubic feet a day (cf/d) of sour gas, largely for a planned onshore liquefied natural gas (LNG) export facility, and 80,000 tonnes a year (t/y) of gas condensate.

CNPC reportedly backed out of phase 11 in 2012, after the Tehran government blamed it for delays in buying equipment and starting preparatory works. France’s Total and Malaysia’s Petronas had previously also pulled out of the scheme.

NIOC and its subsidiaries are developing South Pars in 29 phases, but several of these have been delayed as relations with foreign oil companies are constrained by international sanctions against the Islamic Republic’s energy sector.