The Ayoluengo 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

Sargentes de la Lora Sargentes de la Lora is a municipality located in the province of Burgos, Castile and León, Spain. According to the 2004 census (INE), the municipality has a population of 196 inhabitants. In 1963, a petroleum reservoir was discovered in Ayolue ...

, Province of Burgos. Ayoluengo is the only onshore commercial oil field of Spain (and the only one in the entire Iberian Peninsula).

History

The Ayoluengo oil field was discovered in June 1964 by Amospain (joint venture

Chevron Chevron (often relating to V-shaped patterns) may refer to: Science and technology * Chevron (aerospace), sawtooth patterns on some jet engines * Chevron (anatomy), a bone * ''Eulithis testata'', a moth * Chevron (geology), a fold in rock lay ...

Texaco Texaco, Inc. ("The Texas Company") is an American Petroleum, oil brand owned and operated by Chevron Corporation. Its flagship product is its Gasoline, fuel "Texaco with Techron". It also owned the Havoline motor oil brand. Texaco was an Indepe ...

, Campsa). It was developed by Leni Oil & Gas. It began production in 1967 and produces oil. The total

proven reserves Proven reserves (also called measured reserves, 1P, and reserves) is a measure of fossil fuel energy reserves, such as oil reserves, natural gas reserves, and coal reserves. It is defined as the " antity of energy sources estimated with reasonabl ...

of the Ayoluengo oil field are around 104 million barrels (13.9×10⁶tonnes), and production is centered on . The field produced 17 million barrels of oil from 1967 to 2017, year when the concession of the field expired and a new bid was to be organized. The output sometimes peaked at 5,000 barrels a day, but by 2014, it was around 100 barrels a day. The lands for the oil production were expropriated from the local inhabitants. The region did not benefit economically from the Ayoluengo oil field.

Geology

The 10 km² field consists of a

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

salt-cored

anticline In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

with 200 m of vertical closure. Oil and gas are produced from more than 50 lenticular

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

bodies of Late Jurassic to

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

age. These sandstone bodies lie at a depth of at least 1300 m. The last well was drilled in 1990, making for a total of 52. Only 10 wells were active by 2016, when the cumulative production had reached 17 million barrels of oil.

References

Oil fields in Spain {{Spain-geo-stub