Argentina’s largest offshore production project, the "Carina" and "Aries" reservoirs, are located off the coast of Tierra del Fuego. Discovered in 1983, Carina lies around 80 kilometers off the coast and covers an area of 890 square kilometers. Crude oil and natural gas can be found at a depth of around 1,000 meters below the seabed (the water is between 80 and 100 meters deep). Aries, which is around 30 kilometers from the coast, was discovered in 1981. 12 kilometers long and four kilometers wide, the field stretches below the seabed (the water here is between 60 and 80 meters deep). The gas in the Aries field can be found at a depth of around 1,600 meters and is richer in condensate than the gas found in Carina. Around 12 million cubic meters of natural gas are currently produced from both fields every day.
We use production platforms to extract the gas from the offshore reservoirs in Argentina. The steel constructions consist of two parts: the "jackets" and the "decks". The jackets are firmly anchored to the seabed and support the weight of the platforms. They were made in a shipyard in Louisiana and then shipped to the deposits in 2003. Both as tall as high-rise buildings, the Carina jacket is 80 meters tall and 15 meters wide, while the Aries jacket is 76 meters tall and 15 meters wide. The decks of the production platforms sit on top of the jackets. They were built in the port of Veracruz in Mexico and were shipped toward Tierra del Fuego in 2004. Both platforms are unmanned because the gas, condensate and water are only separated after arriving at the Rio Cullen plant.
Steel structures on the seabed also play a part in producing gas. A pipeline network which is more than 100 kilometers long is needed to transport the gas to the mainland. This sounds easier than it is. The low underwater temperatures alone prove technologically challenging. The temperature on the seabed is around two degrees, which means that the wet gas in the pipes could form hydrates and clog up the pipeline. To prevent this from happening, we add monoethylene glycol (MEG) to the gas to significantly lower the freezing point. The "antifreeze" is later recovered on the mainland.
In addition to low temperatures, the pipeline also has to withstand the enormous pressure of the water column. For this reason, the pipeline of the Carina field (80 kilometers long) has 15-millimeter thick walls, so that it can withstand as much as 96.5 bar. Heavy weights had to be shifted to make this possible with each pipeline element measuring 60 centimeters in diameter, twelve meters in length, and weighing twelve tonnes. The Aries pipeline (21 kilometers long) is a bit slimmer with its diameter of 45 centimeters. Both pipelines have a coating to protect them from being corroded by the aggressive sea water.
In Rio Cullen, the consortium’s processing plants separate the elements of gas, condensate, and water. The plants are designed for a maximum production volume of approximately 14 million cubic meters per day. From Rio Cullen, the gas is piped to the Cañadón Alfa natural gas processing plant. From there, it is sent through the San Martin pipeline, and after travelling more than 3,000 kilometers the offshore gas can be used to provide a secure energy source to major cities and industrial centers in Argentina.