Cymric Oil Field

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Cymric Oil Field

The Cymric Oil Field is a large oil field in Kern County, California, United States. It holds a substantial amount of oil remaining, about 119 million barrels, ranking fifth in California for total remaining reserves. The field has shown the fastest growth in production of any California field in recent years, with peak production reached in 1996 at about 11.7 million barrels.

Setting
The field sits in the Temblor Valley along State Route 33, north of McKittrick. It stretches roughly 11 miles from northwest to southeast and is up to 2 miles wide, with elevations between about 600 and 1,000 feet. Nearby oil areas include McKittrick, Belgian Anticline, Railroad Gap, and Monument Junction, while the South Belridge Field lies about a mile northeast of Cymric’s northern edge. The climate is dry to semi-dry, and much of the natural vegetation has been removed in active oil-producing areas.

Geology
Most Cymric oil lies in the Tulare sandstone formation, which is divided into Tulare I, Tulare II, and Amnicola units, all dating to the Pleistocene. The Tulare sands formed in braided streams and fan delta environments, while Amnicola shows signs of a lake environment as well as braided streams. The rocks have high porosity (about 35%) but relatively low permeability, so oil accumulates in the formation and is trapped by structural and stratigraphic features. The upper Tulare units have been the most productive and were the first to be discovered in 1909.

Other productive formations in the area include the Etchegoin (Pliocene), Reef Ridge (Miocene), the McDonald/Devilwater pool in the Monterey Formation (Miocene), the Temblor formation’s Agua (Santos) pool (Oligocene), and the Kreyenhagen Shale (Eocene). One notable pool, the Carneros pool in the Temblor Formation, was discovered in 1946 and produced over 2.3 million barrels in 1947. Deeper pools were found from the 1940s to the 1980s; for example, the Phacoides pool in the Temblor Formation lies about 10,145 feet deep and erupts oil at surface temperatures around 307°F. The deepest Cymric well reached 12,022 feet in the Point of Rocks formation (Eocene).

History and production
The Cymric field was discovered in 1909 by the Nacirema Oil Company with Well No. 1 in the Tulare pool. Unlike many nearby fields, Cymric’s peak production occurred later, in the mid-1990s. In 1996 it produced about 11.7 million barrels. By 2006 it stood out for its rapid production growth, the fastest among California fields at that time. The crude here is heavy, with API gravity around 11–15, making it difficult to flow; as a result, steam injection (steamflooding) is commonly used to move the oil toward production wells. Wells on Cymric are often closely spaced, with some areas having wells only 110 feet apart.

Operators
Current major operators on the Cymric Field are Chevron Corporation, Aera Energy LLC, and Plains Exploration and Production (PXP), which acquired Nuevo Energy in 2004.