Gas Pipeline

Construction work on the gas pipeline began in 1997, and it was put into commercial service in 1999, just about at the same time as the first unit at the Atacama Power Station, which became commercially operational in September 1999.

Later, a second pipeline was constructed as an extension to the Atacama duct, called the Taltal Pipeline, which begins in the Mejillones area and extends south, to Paposo, where it feeds two natural gas turbines belonging to Endesa, which in turn supply electricity to the Central Interconnected System for Chile (Sistema Interconectado Central de Chile, SIC). In addition, GA constructed a connecting section in 2000, for natural gas supplies to the Altonorte Metallurgical Complex, located at La Negra; as well as another section to connect to the Cerro Dominador Mine.

Gas Pipeline Description:

The transportation of natural gas is comprised of a major 530km-long duct on the Argentinean side, which begins in Coronel Cornejo (Salta) and travels around 230km south-west, into the Province of Jujuy, before turning north-west, passing the town of San Salvador de Jujuy and then Purmamarca, before finally crossing the Argentine Puna to reach the border with Chile.

In Chile, the route continues via the Jama Pass and descends north-west, to the environs of San Pedro de Atacama, where it descends to the city of Calama, and travels another 411km to reach the industrial area of Mejillones, in Chile’s Second Region. This is where the lateral Taltal Pipeline begins, which carries natural gas along its 226km length south, passing La Negra near the city of Antofagasta, and then reaching the reception station for gas at the Taltal Power Station in Paposo, in the borough of Taltal.

Infrastructure

The GasAtacama Pipeline has a diameter of 20 inches, and the Taltal duct has a diameter of between 12 and 16 inches.

The gas transportation system of the pipeline consists of three compressor stations that ensure the necessary pressure to supply the gas requirements, 48 block valve stations that divide the duct into sections of approximately 30km, and 11 gas outlet stations for clients. The system capacity is designed to supply 8.5 million m3/day.

Approximately 50% of the block valve stations are fitted with satellite signaling and Supervisory Control and Data Acquisition (SCADA), as well as measuring instrumentation for operational variables. Some stations in critical locations have automatic shutdown systems for low or high pressure that ensure automatic isolation of a section in case of rupture.

It is important to note that the gas pipeline is controlled and monitored 24hrs-a-day by means of a satellite surveillance system that operates in real time from the operational control center located at the San Salvador de Jujuy Base and from the control headquarters in Santiago de Chile, where an operator is also on 24-hr standby, every day of the year. There is also an auxiliary control room in Antofagasta, which is available in case of a breakdown of service at the other two centers mentioned.

Each one of the control centers is in constant communication with each one of the stations along the pipeline, which in turn are connected to the SCADA. Thanks to this sophisticated control system along the pipeline, it is possible to operate the compression and block valve stations at all times, as well as to adapt to conditions in accordance with the demand requirements of clients.

In addition to the satellite communication system, connectivity is provided via a network of data and voice data throughout all sections of the pipeline. This ensures smooth communication lines between the operational control centers and personnel working on site along the pipeline. All the control centers have emergency (800) telephone lines that enable communication regarding any emergency and all necessary decisions required.

One of the pipeline’s features is that it has achieved complete availability (100%), underlining the excellence of operational activities and maintenance standards for gas transportation maintained by GasAtacama.