The Sarir Field was discovered in southern Cyrenaica

Cyrenaica

Cyrenaica is the eastern coastal region of Libya.Also known as Pentapolis in antiquity, it was part of the Creta et Cyrenaica province during the Roman period, later divided in Libia Pentapolis and Libia Sicca...

 during 1961 and is considered to be the largest oil field

Oil field

An oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...

 in Libya

Libya

Libya is an African country in the Maghreb region of North Africa bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south, and Algeria and Tunisia to the west....

, with estimated oil reserves of 12 Goilbbl. Sarir is operated by the Arabian Gulf Oil Company

Arabian Gulf Oil Company

The Arabian Gulf Oil Company is an oil company based in Benghazi, Libya, engaged in crude oil and natural gas exploration, production and refining. It was a subsidiary of the state-owned National Oil Corporation . -Overview:...

 (AGOCO), a subsidiary of the state-owned National Oil Corporation

National Oil Corporation

The National Oil Corporation is the national oil company of Libya. It dominates Libya's oil industry, along with a number of smaller subsidiaries, which combined account for around 70% the country's oil output...

 (NOC).
The Sarir field or, more specifically, Sarir C is on west edge of the Calanscio Sand Sea at the southeast margin of the Sirte Basin

Sirte Basin

The Sirte Basin is a late Mesozoic and Tertiary triple junction continental rift along northern Africa that was initiated during the late Jurassic Period. It borders a relatively stable Paleozoic craton and cratonic sag basins along its southern margins...

. Sarir C, which is part of a three-field complex, is 56 km long and 40 km wide covering 378 km².