The Albacora-Leste Oil Field is an

oil field A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence ...

located in

Campos Basin The Campos Basin is one of 12 coastal sedimentary basins of Brazil. It spans both onshore and offshore parts of the South Atlantic with the onshore part located near Rio de Janeiro. The basin originated in Neocomian stage of the Cretaceous period ...

. It was discovered in 1986 and developed by

Petrobras Petróleo Brasileiro S.A., better known by the portmanteau Petrobras (), is a state owned enterprise, state-owned Brazilian multinational corporation in the petroleum industry headquartered in Rio de Janeiro, Brazil. The company's name transla ...

. The oil field is operated by

, that owns 90% of the field, while Repsol owns the remaining 10%. The total proven reserves of the Albacora-Leste oil field are around 534 million barrels (72×10⁶tonnes), and production is centered on . In April 2022, Petro Rio (through its subsidiary Petro Rio Jaguar Petróleo), acquired a 90% operating stake in the Albacora Leste field Petróleo Brasileiro (Petrobras) for $2.2bn USD.

Geology

The Albacora field consists of several producing horizons of Albian to Miocene sandstone turbidites, with an area of 235 km².Candido, A., and Cora, C.A.G., 1992, The Marlim and Albacora Giant Fields, Campos Basin, Offshore Brazil, AAPG Memoir 54, Halbouty, M.T., editor, Tulsa: American Association of Petroleum Geologists,

Reflection seismology Reflection seismology (or seismic reflection) is a method of exploration geophysics that uses the principles of seismology to estimate the properties of the Earth's subsurface from reflected seismic waves. The method requires a controlled seismi ...

in 1972 disclosed a faulted anticline and seismic amplitude

bright spot In reflection seismology, a bright spot is a local high amplitude seismic attribute anomaly that can indicate the presence of hydrocarbons and is therefore known as a direct hydrocarbon indicator. It is used by geophysicists in hydrocarbon explora ...

, which was drilled by wildcat 1-RJS-297 in 1984 and discovered oil. The

stratigraphy Stratigraphy is a branch of geology concerned with the study of rock (geology), rock layers (Stratum, strata) and layering (stratification). It is primarily used in the study of sedimentary rock, sedimentary and layered volcanic rocks. Stratigrap ...

of the Campos Basin starts with the Lower Cretaceous Lago Feia

Formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

a source rock, followed by the Albian Macae Formation consisting of shallow water carbonates overlain by late Albian

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

marl Marl is an earthy material rich in carbonate minerals, clays, and silt. When hardened into rock, this becomes marlstone. It is formed in marine or freshwater environments, often through the activities of algae. Marl makes up the lower part o ...

calcilutite Calcilutite (also known as cementstone) is a type of limestone that is composed of predominantly, more than 50 percent, of either clay-size or both silt-size and clay-size detrital (transported) carbonate grains. These grains consist either of foss ...

s, and turbidite sandstones. From this formation through most of the

Cenozoic The Cenozoic ( ; ) is Earth's current geological era, representing the last 66million years of Earth's history. It is characterised by the dominance of mammals, birds and flowering plants, a cooling and drying climate, and the current configura ...

, the Campos Formation was deposited, consisting of deep water turbiditic sandstones and shales, the main producers in the Albacora and

Marlim Marlim is a giant Brazilian oil field located in the north-eastern part of the Campos Basin, about 110 km offshore Rio de Janeiro, in water depths ranging from 650 to 1,050 m. Marlim means marlin, in Portuguese. Marlim was originally disc ...

fields. Finally, the basin was filled by the Ubatuba Formation, consisting of slope and shelf deposits.

References

{{coord missing, Brazil Oil fields of Brazil Campos Basin Petrobras oil and gas fields