Guijarral Hills Oil Field

Guijarral Hills Oil Field
The Guijarral Hills Oil Field in central California. Other oil fields are shown in dark gray.
Country	United States
Region	San Joaquin Basin
Location	Fresno County, California
Offshore/onshore	onshore
Operator	Longview Natural Resources
Field history
Discovery	1948
Start of development	1948
Start of production	1948
Peak year	1950
Production
Current production of oil	1.4 barrels per day (~70 t/a)
Estimated oil in place	0.037 million barrels (~5,000 t)
Producing formations	Temblor Formation (Miocene), Lodo Formation (Eocene)

The Guijarral Hills Oil Field is a formerly-productive oil and gas field near Coalinga on the western side of the Central Valley in central California in the United States. Discovered in 1948, and having produced 5.4 million barrels (860,000 m³) of oil during its peak year in 1950, it now has but one active oil well producing a little over a barrel of oil a day, and is very near to exhaustion, with only 343,000 recoverable barrels of oil remaining throughout its 2,515-acre (10.18 km²) extent according to the official California State Department of Conservation estimate. As of 2010, the only active operator was Longview Production Company.

The Guijarral Hills are a low range of hills, rising a little more than a hundred feet above the floor of the San Joaquin Valley to the east, and scarcely noticeable in the shadow of the nearby Coast Range of central California. These low hills are the surface expression of the southern portion of the Coalinga Anticline, which separates the smaller, largely agricultural Pleasant Valley to the west from the main portion of the California Central Valley to the east. The town of Coalinga is about eight miles (13 km) west of the hills, with the large Coalinga Oil Field wrapping around the town in a crescent shape. The Guijarral field is a similar, smaller, and separate field southeast of the giant Coalinga field.

The major road through the field is Jayne Avenue, which runs east to west, connecting Interstate 5 to Coalinga. California State Route 33 runs from north to south, west of the field, joining with Jayne Avenue. The Pleasant Valley State Prison, also on Jayne Avenue, is adjacent to the oil field on the west.

Climate in the area is arid to semi-arid, and native vegetation consists of grassland and low scrub. Summertime temperatures routinely exceed 100 °F (38 °C), and freezes occur during the coldest months, although snow is rare. Most precipitation occurs in the winter. Runoff to the west and north is into Los Gatos Creek, which flows northeast into the San Joaquin Valley; runoff to the south and east is into Zapato Chino Creek, which joins with Los Gatos Creek draining to the northeast. Elevations in the vicinity range from around 500 feet (150 m) in Los Gatos Creek north of the hills to 733 feet (223 m) at the highest point in the hills; the productive portion of the oil field ranges from around 550 to 650 feet (200 m) above sea level.