The Russell Ranch Oil Field is an oil and gas field in the

Cuyama Valley The Cuyama Valley (Chumash: ''Kuyam'', meaning "Clam") is a valley along the Cuyama River in central California, in northern Santa Barbara, southern San Luis Obispo, southwestern Kern, and northwestern Ventura counties. It is about two hours ...

of northern Santa Barbara and southern

San Luis Obispo San Luis Obispo (; Spanish for " St. Louis the Bishop", ; Chumash: ''tiłhini'') is a city and county seat of San Luis Obispo County, in the U.S. state of California. Located on the Central Coast of California, San Luis Obispo is roughly hal ...

Counties, California, in the United States. Discovered in 1948, and reaching peak production in 1950, it has produced over of oil in its lifetime; with only an estimated of recoverable oil remaining, and having produced around 66,000 in 2008, it is considered to be close to exhaustion. The primary operator on the field as of 2010 is E&B Natural Resources, which also runs the nearby

South Cuyama Oil Field The South Cuyama Oil Field is a large oil and gas field in the Cuyama Valley and the adjacent northern foothills of the Sierra Madre Mountains in northeastern Santa Barbara County, California. Discovered in 1949, and with a cumulative production ...

. p. 100, 126

Setting

The oil field one of the two significant fields in the Cuyama Valley, the other being the much larger

. The Russell Ranch field is about seven miles (11 km) west-northwest of the town of

New Cuyama New is an adjective referring to something recently made, discovered, or created. New or NEW may refer to: Music * New, singer of K-pop group The Boyz Albums and EPs * ''New'' (album), by Paul McCartney, 2013 * ''New'' (EP), by Regurgitator, ...

. The total productive area is about , and the field is about five miles (8 km) long by one-half mile across, with the long axis trending approximately northwest to southeast, beginning at Whiterock Bluff in the

Caliente Range The Caliente Range is a west-east trending zone of uplift mountains in the California Coast Ranges, in central California. The highest peak of the range is Caliente Mountain at in elevation, located in southeastern San Luis Obispo County. Geolog ...

, crossing under the

Cuyama River The Cuyama River (Chumash: ''Kuyam'', meaning "Clam") is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed March 15, 2011 river in southern San Luis Obispo County, northern Santa Barbar ...

, and ending in the foothills of the Sierra Madre Mountains.Barger, R.M. and J.L. Zulberti. ''Russell Ranch Oil Field: California Division of Oil and Gas, Summary of Operations''. 1952. Vol. 38 No. 2. pp. 5-6. The Cuyama River, and California State Route 166 which parallels the river, cut through the center of the field; travelers on Route 166 have a brief view of oil storage tanks and several pumpjacks, but most of the oilfield operations are out of sight from the public right-of-way. Elevations on the field range from around where the river cuts across the field, to around at the southern end in the hills. Terrain consists of an alluvial plain around the river, and grass- and brush-covered hills, cut by numerous gullies and badlands, at both ends of the field in the lower portion of the Caliente and Sierra Madre mountains. Climate is

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western Europe, Western and Southern Europe and Anatolia, on the south by North Africa ...

, but modified by the distance from the coast; winters are colder, with occasional freezes, and summertime temperatures sometimes top . Drainage is to the Cuyama River, which flows out to the ocean at Guadalupe. In the vicinity of the oil field, the predominant land use, aside from activities associated with oil production and storage, is cattle grazing. The bottomlands of the Cuyama Valley, adjacent to the field on the east-southeast, are primarily agricultural.

Geology

Unlike many oil fields in central California, the Russell Ranch field is not an anticlinal formation with an obvious surface expression – indeed the geologic formation containing oil is quite invisible from the ground surface, being covered with alluvium and masked by the mountain ranges running almost perpendicular to the oil field. The oil is in a large

homocline In structural geology, a homocline or homoclinal structure (from old el, homo = same, cline = inclination), is a geological structure in which the layers of a sequence of rock strata, either sedimentary or igneous, dip ...

, including porous

sedimentary Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

units dipping northeast and essentially planar, which terminate at the Russell Fault, a normal fault with an approximately vertical offset which has barricaded upwards movement of

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...

s against impermeable rock of

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Santa Margarita and Vaqueros Formations, of late and early

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

age respectively – are sandstones with a porosity of between 23 and 32 percent.California Department of Conservation, Division of Oil, Gas, and Geothermal Resources (DOGGR). ''California Oil and Gas Fields, Volumes I, II and III''. Vol. I (1998), Vol. II (1992), Vol. III (1982). PDF file available on CD from www.consrv.ca.gov. p. 440 The oil field has four separate pools or producing horizons within its main area, and one small pool in another area about one-half mile southeast of the main part of the field. The four pools in the main area, all discovered in 1948 and 1949, are the Santa Margarita, in the formation of the same name, of late Miocene age; and the Dibblee, Griggs-Dibblee, and Colgrove, all in the Vaqueros Formation of early Miocene age. The pool in the Southeast Area is also in the Dibblee Sand of the Vaqueros Formation. Depths of the pools range from below ground surface in the Santa Margarita to 3,600 in the Dibblee Sand in the Southeast area, and oil is of medium grade, with

API gravity The American Petroleum Institute gravity, or API gravity, is a measure of how heavy or light a petroleum liquid is compared to water: if its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks ...

ranging from 25 to 40. Sulfur content is generally low, with values from 0.26 to 0.46 percent in each of the pools.

History, production, and operations

The Russell Ranch field was the first to be found in the Cuyama Valley. Prospectors had long suspected the presence of oil there – after all, almost all the surrounding basins were full of oil fields, which only needed to be found by drilling deep enough – but early boreholes found nothing of commercial value. A well drilled in the 1920s near the western edge of the field found nothing, and wells drilled in 1945–6 found traces of oil sands, a promising sign. Norris Oil Company put in the discovery well on January 1, 1948, which produced ; unfortunately the production turned to water quickly, and prospectors began looking for a more favorable location. Richfield Oil Company, an ancestor of ARCO (now BP), put in the well which found the most productive area of the field, drilling to a depth of into the Dibblee Sand (named for

Thomas Dibblee Thomas Wilson Dibblee, Jr. (11 October 1911, in Santa Barbara, California – 17 November 2004, in Santa Barbara, California) was an American geologist best known for his geological mapping. He is also known, together with co-author Mason H ...

, the geologist who led Richfield to explore for oil in the Cuyama Valley). This well produced over , and many more wells followed; each of the producing horizons had been discovered before 1950, and by July 1, 1950, there were 142 producing wells on the field. The success of the Russell Ranch field development led quickly to the discovery of the South Cuyama field about seven miles (11 km) to the southeast, in 1949; this field proved to have over three times the oil of the Russell Ranch field, and remains the largest in the Cuyama Valley. The field reached its peak production in 1950, when of oil were withdrawn from the reservoir. Inevitably, production declined, and field operators employed several enhanced recovery technologies to increase reservoir pressure and keep the wells flowing. Waterflooding was begun in 1953, and air injection in 1971. A cyclic steam program ran from 1966 to 1968 but failed to produce any significant benefit. The field changed hands several times, with West America Resources and J.P. Oil among the owners prior to the purchase by E&B Natural Resources from J.P. Oil in 2003. E&B, the current operator, reported pumping of oil in 2008; its wells were averaging only , a figure typical of a field near the end of its useful life. At the end of 2008, there were 44 wells still active on the field, all operated by E&B. All but one of these wells was in the Main Area; the other was the solitary well still producing in the Southeast Area.

References

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