Overview of Biggest Producing Fields in Libya

Libya has the largest proven oil reserves in Africa, but according to the US-based Energy Information Administration (IEA) the country remains under explored. As of 2005, only about 25 percent of Libya's territory was covered by agreements with oil companies. Reasons for the underexploration of Libya include sanctions, a lack of modern technology, and stringent fiscal terms imposed by Libya on foreign oil companies.

Below is an overview of the country's most important producing fields:

=Sarir oil field=

The Sarir field is located onshore about 500 kilometres east of Tripoli in the Sirte Basin and contains some 12 billion barrels (bbl) of oil. Sarir is a supergiant oil field and considered to be the largest in Libya. The field was discovered by British BP in 1961 at a depth of approximately 2,700 metres and was pumping around 420,000 barrels per day (bpd) before the 2011 conflict (roughly one quarter of total national production), compared to 250,000 bpd in 1992. Oil produced at Sarir is very waxy, with 37.2 degree API gravity, and is pumped through a 400-kilometre pipeline to the Marsa El Hariga terminal. Production at the field was halted for several months in 2011 due to sabotage attacks by pro-Gaddafi forces.

Sarir is operated by Libyan National Oil Corporation (NOC) subsidiary Arabian Gulf Oil Company (Agoco). BP and Hunt each had a 50 percent stake in the field until Libya nationalised BP's assets in September 1971, after which the NOC acquired the remaining 50 percent from Hunt in July 1973.

=Sharara oil field=

The giant Sharara oil field is located in Block NC 115 of the Murzuq basin, about 730 kilometres south of Tripoli.

The field was discovered by Petrom, a Romanian oil and gas company, in the 1980s and began production in December 1996. By 2006 it was producing about 200,000 barrels per day (bpd) of high quality crude oil. Since mid-1998, the light and sweet crude produced at Sharara has been exported by pipeline through the Zawia terminal west of Tripoli.

The field has a capacity of 400,00 bpd and before the outbreak of conflict in 2011 accounted for a quarter of Libyan production. (although other sources cite maximum capacity lower at 340,000 bpd). By February 2012 the NOC announced that production at the site had again reached 300,000 bpd, despite delays over security concerns.

Spain's Repsol holds a 10 percent stake in the Sharara field in partnership with the NOC (75%), France's Total (7.5%) and Austria's OMV (7.5%), through the Joint Venture (JV) Akakus Oil Operations.

=Elephant Oil Field=

The giant Elephant oil field, also known as El Feel, contains more than 1.2 billion barrels (bbl) of reserves, and as of 2007 was the biggest oil field in the Murzuq basin.

It was discovered in 1997 by a consortium led by British company Lasmo, along with Italy's Eni and five South Korean companies at the NC-174 Block, some 750 km south of Tripoli. Elephant began production in 2004 at around 10,000 bpd, a figure that rose to 125,700 bpd by 2010. Elephant is operated by Lasmo, which has been a part of Italy's Eni energy group since Eni acquired the company in December 2000.

The field produces a grade of crude oil marketed as Mellitah.

=Waha Oil Fields=

Located in the central/southern part of the Sirte Basin in the centre-east of Libya, the Waha oil fields are the oldest producing fields in Libya, dating back to the 1950s. They had a capacity of around 350,000 barrels of oil equivalent (boe) per day as of 2009, a decrease from about 1 million bpd in 1969 and 400,000 bpd in 1986. In July 2012 the group of fields was producing at a rate of 345,000 barrels of oil equivalent (boe) per day.

Owned by NOC subsidiary Waha Oil Company, the Waha oil fields are operated by the Oasis Group, an international consortium made up of US-based companies ConocoPhillips, Marathon and Hess.

The concession includes three major projects, Faregh II, NC-98 and North Giato. In 2012 the Libyan government identified blocks NC-98 and North Gialo as key to restoring production levels to pre-sanction levels. At plateau production, NC-98 should deliver 80,000 bpd of condensate and 13.6 million cubic metres per day of natural gas. North Gialo is expected to produce 100,000 bpd of crude and 5.7 million cubic feet per day of gas.

The Waha fields supply crude oil to the marine terminal at Es Sider, on the Gulf of Sidra, via a 430-kilometre pipeline. The pipeline begins in Gialo field, is routed through Waha and Samah then continues north to Dahra before arriving at Es Sider, where tankers berthed just offshore are loaded.

=El Bouri Oil and Gas Field=

Located in the Tripolitanian Basin about 130 kilometres north west of Tripoli, El Bouri is Libya's first offshore field with a large gas cap. It is the largest producing oil field in the Mediterranean Sea with production at 44,500 bpd as of 2009.

El Bouri is operated by Agip North Africa Middle East (NAME), a part of Eni group, through the joint venture Mellitah Oil and Gas.

Containing an estimated 70.8 billion cubic meters (bcm) of gas and some 4-5 billion barrels (bbl)of oil, El Bouri was discovered in 1976 in Block NC 41-B in the Libyan sector of the Gulf of Gabes. It lies at a depth of 2,650 meters and covers an area of 32 x 5 kilometres.

El Bouri came on stream in August 1988 at a rate of 12,000 bpd. By the end of 1988 production had risen to 20,000 bpd and in 1989 it rose to 60,000 bpd. Capacity was again raised to 70,000 bpd by mid-1991 after another 27 wells were drilled. A second-phase capacity expansion to 150,000 bpd was reached in 1995, requiring the drilling of 55 new wells from three new platforms, but the field's output fell subsequently because it required enhanced oil recovery (EOR) facilities and by 1998 was averaging production of about 60,000 bpd. Following the disruption of the 2011 conflict the El Bouri field resumed production, at an initial rate of 10,000 bpd, in November 2011.

The gas-to-oil ratio, which refers to the relative amounts of natural gas and petroleum that are simultaneously removed from the ground, of El Bouri's output has been about 22.7-25.5 cubic meters per barrel, limiting its recovery rate. Because associated natural gas tends to escape the gas-oil solution upon extraction and can continue at each stage of transportation and processing, thereby reducing the volume of oil, wells that have a high gas-oil ratio are generally considered economically undesirable. As of 2005, there were plans in place to lower the gas-oil ratio at El Bouri to about 17 cubic meters per barrel, through the drilling of 15 horizontal wells.

=Libyan Oil Production (bpd) by field=



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