The SEA Gas pipeline (South East Australia Gas pipeline) is a 687km natural gas pipeline from the Iona Gas Plant in Victoria to the Pelican Point Power Station at Port Adelaide. It connects Adelaide's gas supply to Melbourne and Sydney's, thus increasing the security of natural gas supply to Adelaide. The pipeline is operated by the SEA Gas joint venture formed in May 2001 by Pelican Point Power (a subsidiary of International Power and operator of the Pelican Point Power Station) and Origin Energy (a major Australian energy producer and retailer). In September 2003, TRUenergy (owner and operator of the Torrens Island Power Station) joined as an equal one-third partner.
The requirement for an upgrade to South Australia's natural gas infrastructure was first identified in June 2000 when the capacity of the MAP (Moomba to Adelaide Pipeline) was close to being fully utilised. At this time, the MAP was the sole source of natural gas for Adelaide. As about two thirds of electricity consumed in South Australia was produced by gas-fired power stations, it was determined that the state needed an additional source of supply of natural gas. An additional factor was the redundancy provided by having two independent supplies.
The need for this redundancy was dramatically confirmed when a fire at Moomba cut most of Adelaide's gas supply on the day SEA Gas began operation. The new pipeline supplied nearly all of Adelaide's gas needs at times while the damage was repaired.
The initial proposal was to build a 14" diameter high-pressure gas pipeline, operating at 15MPa. This was modified to dual 14" pipes for 338km of the route and an 18" pipe for the remainder when TRUenergy joined SEA Gas as to accommodate the additional capacity required by the Torrens Island Power Station. Construction commenced in October 2002, 180 km south east of Adelaide near Tintinara. Operations commenced on 1 January 2004, however the project was not officially opened until 15 March 2004. Construction was carried out on an engineer-procure-construct (EPC) basis by a joint venture between Australian pipeline company AJ Lucas Group and French company Spie Capag.