Sarir oil field
| Sarir Field | |
|---|---|
 |
|
| Country | Libya |
| Location/block | Sirte Basin, Concession 65 |
| Offshore/onshore | Onshore |
| Coordinates | 28°13′N 19°08′E / 28.22°N 19.13°E |
| Operator | Arabian Gulf Oil Company |
| Partner | National Oil Corporation |
| Field history | |
| Discovery | 1961 |
| Start of production | 1961 |
| Peak of production | NA |
| Abandonment | NA |
| Production | |
| Estimated oil in place | 2,922 Mbbl (464,600,000 m3) (Sarir C): 1,200 Mbbl (190,000,000 m3) (Sarir L) |
| Estimated gas in place | 0.6×1012 cu ft (17 km3) (Sarir C) |
| Producing formations | Cretaceous, Pre-Upper Cretaceous Fluvial Sandstones |
The Sarir Field was discovered in southern Cyrenaica during 1961 and is considered to be the largest oil field in Libya, with estimated oil reserves of 12 Gbbl (1.9 km3). Sarir is operated by the Arabian Gulf Oil Company (AGOCO), a subsidiary of the state-owned National Oil Corporation (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. Sarir C, which is part of a three-field complex, is 56 km long and 40 km wide covering 378 km². To its north is Sarir L, covering 15 sq mi (39 km2). Situated between the two is a much smaller Sarir North pool. Estimated ultimate oil recovery from Sarir L is 1.2 Gbbl (190,000,000 m3).
In 1957, the Libyan government granted Concession 65 to Bunker Hunt, an independent oil producer from Texas. By 1960, BP had assumed a 50% interest in C-65 and became the operator. After large discoveries in the Sirte Basin in 1958 and 1959, a reflection seismology survey was conducted on C-65, followed by an aeromagnetic survey showing the existence of large structures. Later that year, BP began drilling in C-65, 80, and 81, targeting Paleocene and Cretaceous carbonates that had yielded discoveries in the Nasser (Zelten), Defa, Raguba field, and Bahi fields. Mobil discovered Cretaceous basal sand at Amal in 1959, but early results did not recognize its full potential.
Before drilling the C-1-65 well, BP drilled six tests to basement in C-65, 80, and 81. None had high hydrocarbon shows. Eocene, Paleocene, and Cretaceous carbonates were generally freshwater bearing, and basement highs were draped in Late Cretaceous shales. There were occasional redbed vestiges at the shale-basement contact and bitumen veining. Many wells proved expensive due to lost circulation in Paleocene-Cretaceous carbonates and caving in underlying Late Cretaceous shales. This was so severe that the Sarir field was nearly bypassed because oil was not anticipated in the Nubian Formation. However BP's chief geologist insisted a basement core be taken in every well. This turned out to be a good decision, since C-1-65 was subsequently shown to be a prolific reservoir with initial production rates of 20,000 bbl/d (3,200 m3/d).
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Wikipedia