Producing basins

Northwest Basin

The northern basin: the one that for years supplied gas to Argentina and Chile, and that today produces a fraction of what it once did. It has two distinct geological worlds.

Where it is

It covers northern Salta, eastern Jujuy and western Formosa. The part that produced the most is the Subandean fold belt, the ranges running from Tartagal to the Bolivian border (Aguaragüe, Ramos, San Pedrito, Macueta). Farther east is the Cretaceous subbasin (Lomas de Olmedo), with oil at Palmar Largo and Caimancito.

How it produces

In the Subandean ranges the gas is very deep, generally below 4,000 meters, in highly fractured Devonian sandstones (Huamampampa, Icla and Santa Rosa formations). Wells are few, expensive and hard to drill (hard formations, high pressure, folded structures) but very high-rate: a good well at Ramos or Acambuco produced more than a million m³ per day. Condensate, a very light oil, comes out with the gas.

History

Campo Durán was discovered in 1951 and gave rise to the refinery of the same name (today Refinor). Ramos, Aguaragüe and Acambuco sustained gas production in the north and, from the late nineties, exports to Chile through the Norandino and GasAtacama pipelines.

Today

The large fields are mature and no discoveries have replaced them. Gas fell from more than 20 million m³ per day in 2004 to less than 3 million. The Gasoducto Norte, which carried gas from the north and from Bolivia toward the center of the country, was reversed in 2024 and now Vaca Muerta gas flows north.

For a supplier

Little drilling activity; work on well and plant maintenance, interventions and services in remote areas (Tartagal, General Mosconi, Aguaray). Deep exploration projects, when they appear, call for high-power drilling rigs.

Production of June 2026. More areas in Areas and Operators.

Cuyo Basin

The smallest of the five basins and almost exclusively oil. It is among the oldest in the country and today lives off squeezing old fields.

Where it is

In northern and central Mendoza, around Greater Mendoza, Luján de Cuyo, Tupungato and Rivadavia. It is an ancient Triassic rift valley: the source rock is the Cacheuta Formation and the main reservoirs are the Barrancas, Potrerillos and Río Blanco formations.

How it produces

Vertical wells, shallow compared with other basins, in fields that have been producing for between 50 and 80 years. Almost all the oil comes out thanks to secondary recovery: water is injected to push the crude toward the producing wells, so for every cubic meter of oil many of water are produced, which must be treated and reinjected. It produces very little gas.

History

Oil was found at Cacheuta from the late 19th century, with the first private ventures in Mendoza. The large fields (Barrancas, La Ventana, Vizcacheras, Tupungato, Río Tunuyán) were developed in the mid-20th century and have supplied the Luján de Cuyo refinery ever since.

Today

Production has fallen by about two thirds since 2004. In 2024-2025 YPF left its mature areas (Plan Andes) and the main fields passed to mid-size operators, such as Petróleos Sudamericanos at Barrancas, Vizcacheras, La Ventana and Mesa Verde. The new owners aim to cut costs and slow the decline.

For a supplier

Pulling and workover services, surface facility maintenance, water treatment and injection, mechanical pumping, piping and equipment repair. Smaller operators that buy at a different pace and on different terms than YPF.

Production of June 2026. More areas in Areas and Operators.

Neuquén Basin

The basin that now explains almost everything: three out of every four barrels of oil and more than two thirds of the country's gas. And the only one that is growing.

Where it is

It spans Neuquén, northern Río Negro, southern Mendoza (Malargüe) and western La Pampa. Its source rock, Vaca Muerta, is a shale formation from the Late Jurassic and Early Cretaceous that extends over about 30,000 km².

How it produces

Two worlds coexist. The unconventional: horizontal wells with laterals of 2,500 to more than 4,000 meters, fractured in dozens of stages, drilled several at a time from the same pad; each well's production falls fast in the first year, so you have to keep drilling to grow. The conventional: mature fields with secondary recovery (Puesto Hernández, El Trapial, Chihuido de la Sierra Negra, Entre Lomas) and gas from low-permeability reservoirs (tight gas).

History

The first oil came out at Plaza Huincul in 1918. Loma La Lata, discovered by YPF in 1977, was for decades the heart of Argentine gas. From 2004 conventional production fell year after year, until in 2011 YPF tested Vaca Muerta and in 2013 began, together with Chevron, the development of Loma Campana. Since 2021 growth has been rapid.

Today

The basin's oil has tripled since 2020. The limit is no longer drilling but takeaway: oil pipelines (Oldelval, VMOS), gas pipelines (Perito Moreno) and treatment plants. See oil and gas pipelines and frac stages per month.

For a supplier

This is where demand is greatest: fracturing, sand, water, drilling, facilities, pipelines, tanks, ASME/API equipment, logistics and services in Añelo and Neuquén city. It also has the most competition and the highest qualification requirements.

Production of June 2026. More areas in Areas and Operators.

Golfo San Jorge Basin

The cradle of Argentine oil and the country's great conventional basin. It was the top oil producer until Vaca Muerta overtook it.

Where it is

Around the Golfo San Jorge: southern Chubut (Comodoro Rivadavia, Sarmiento) and northern Santa Cruz (Caleta Olivia, Pico Truncado, Las Heras). People speak of the north flank (Chubut) and the south flank (Santa Cruz).

How it produces

The reservoirs are many small, stacked sand bodies (Comodoro Rivadavia, Mina del Carmen and Bajo Barreal formations), so each well crosses several producing layers. It is the basin with the most secondary recovery in the country: water is injected on a large scale and production comes out with a lot of water. To keep producing oil from already swept layers, tertiary recovery is applied, mainly polymer injection (projects at Manantiales Behr, Diadema and Cerro Dragón, among others). The typical crude is Escalante, medium to heavy, exported through Caleta Córdova and Caleta Olivia.

History

On December 13, 1907, in Comodoro Rivadavia, a well that was looking for water found oil: that is Oil Day. Cerro Dragón, operated by Pan American Energy, is the largest conventional oil field in the country.

Today

Production has dropped by about 40% since 2006 and keeps falling slowly. Between 2024 and 2025 YPF sold its mature areas: Manantiales Behr went to Pecom, Los Perales-Las Mesetas to Patagonia Resources, Cañadón de la Escondida-Las Heras to Clear Petroleum and Cañadón León-Meseta Espinosa to Quintana, among others. The unconventional potential of the D-129 Formation, the basin's source rock, is being explored.

For a supplier

A lot of work on existing wells: pulling, workover, mechanical pumping, rods and tubing, water and polymer injection plants, crude and water treatment, maintenance. New operators, focused on cost, looking for local suppliers in Comodoro and Caleta Olivia.

Production of June 2026. More areas in Areas and Operators.

Austral Basin

On paper it looks like a single basin, but in production terms it is two with completely different histories: the onshore one, on land, with declining conventional oil and gas; and the offshore one, in the sea off Tierra del Fuego, gas-producing, with a few very large wells and output that rises every time a new field comes on.

Geologically it is the same basin that Chile calls the Magallanes Basin. The main reservoir on both sides is the Springhill Formation (Lower Cretaceous), sandstones resting on the basement. The source rock is the Lower Inoceramus Formation, known in Argentina as Palermo Aike and now studied as a possible unconventional resource, the "Vaca Muerta of the south".

Two basins in one

The Cuenca Marina Austral 1 concession includes, in addition to the offshore fields, some coastal fields in Tierra del Fuego operated from the same plants; we count them within offshore because production is reported together.