Mesa Oil Field
Encyclopedia
The Mesa Oil Field is an abandoned oil field
Oil field
An oil field is a region with an abundance of oil wells extracting petroleum from below ground. Because the oil reservoirs typically extend over a large area, possibly several hundred kilometres across, full exploitation entails multiple wells scattered across the area...

 entirely within the city limits of Santa Barbara, California
Santa Barbara, California
Santa Barbara is the county seat of Santa Barbara County, California, United States. Situated on an east-west trending section of coastline, the longest such section on the West Coast of the United States, the city lies between the steeply-rising Santa Ynez Mountains and the Pacific Ocean...

, in the United States. Discovered in 1929, it was quickly developed and quickly declined, as it proved to be but a relatively small accumulation of oil in a single geologic formation. While the field was active in the 1930s, residential development in most of the Mesa neighborhood of Santa Barbara came to a halt. The field included two major productive areas with a total surface extent of only 210 acre (0.8498406 km²), and produced 3700000 barrels (588,252,991.5 l) of oil during its brief lifetime. p. 95.

Geographic setting

The field occupied a small area on a mesa
Mesa
A mesa or table mountain is an elevated area of land with a flat top and sides that are usually steep cliffs. It takes its name from its characteristic table-top shape....

 to the west of the Santa Barbara Harbor, within the limits of the City of Santa Barbara, now the location of the neighborhood known as "The Mesa". The mesa
Mesa
A mesa or table mountain is an elevated area of land with a flat top and sides that are usually steep cliffs. It takes its name from its characteristic table-top shape....

 from which the neighborhood takes its name is about two miles (3 km) long from west to east and about 3000 feet (914.4 m) across from north to south. The northern boundary is Lavigia Hill, which rises north of Cliff Drive; some of the oil wells were drilled on the southern slopes. The southern boundary of the mesa is the abrupt drop-off at the cliff overlooking the ocean. The cliffs rise 120 feet (36.6 m) above the beach at the western end of the mesa, gradually diminishing in height to only 40 feet (12.2 m) at the eastern end, near Santa Barbara City College
Santa Barbara City College
Santa Barbara City College is a two-year community college founded in 1909. It is located on a campus right over the beach in the city of Santa Barbara, California, USA. SBCC offers associate degrees in English, Social Sciences, Computer Science, Engineering, Physics, and occupational and...

. Prior to the oil field being developed, the flat top of the mesa was farmland, with one imposing former residence, the abandoned and earthquake-damaged "Dibblee Castle" built at the eastern end, overlooking Santa Barbara harbor.

Climate in the area is Mediterranean
Mediterranean climate
A Mediterranean climate is the climate typical of most of the lands in the Mediterranean Basin, and is a particular variety of subtropical climate...

, with mild, sometimes rainy winters and dry summers, with the temperature moderated by ocean breezes and a morning marine layer
Marine layer
A marine layer is an air mass which develops over the surface of a large body of water such as the ocean or large lake in the presence of a temperature inversion. The inversion itself is usually initiated by the cooling effect of the water on the surface layer of an otherwise warm air mass...

. Freezes are extremely rare. Mean annual temperature is approximately 60 °F (15.6 °C), and the growing season is year-round.

Numerous other oil fields exist within the region. The Summerland Oil Field
Summerland Oil Field
The Summerland Oil Field is an inactive oil field in Santa Barbara County, California, about four miles east of the city of Santa Barbara, within and next to the unincorporated community of Summerland...

, location of the world's first offshore oil wells into the ocean, is about seven miles (11 km) to the east of the field; the large Ellwood Oil Field
Ellwood Oil Field
Ellwood Oil Field and South Ellwood Offshore Oil Field are a pair of adjacent, partially active oil fields adjoining the city of Goleta, California, about twelve miles west of Santa Barbara, largely in the Santa Barbara Channel...

 is about ten miles (16 km) to the west. Approximately seven miles to the southeast in the Santa Barbara Channel is the Dos Cuadras Oil Field, source of the 1969 Santa Barbara oil spill
1969 Santa Barbara oil spill
The Santa Barbara oil spill occurred in January and February 1969 in the Santa Barbara Channel, near the city of Santa Barbara in Southern California. It was the largest oil spill in United States waters at the time, and now ranks third after the 2010 Deepwater Horizon and 1989 Exxon Valdez spills...

.

Geology

The structure of the Mesa field is relatively simple. Oil was trapped in two anticlinal
Anticline
In structural geology, an anticline is a fold that is convex up and has its oldest beds at its core. The term is not to be confused with antiform, which is a purely descriptive term for any fold that is convex up. Therefore if age relationships In structural geology, an anticline is a fold that is...

 structures in a band of the porous Miocene
Miocene
The Miocene is a geological epoch of the Neogene Period and extends from about . The Miocene was named by Sir Charles Lyell. Its name comes from the Greek words and and means "less recent" because it has 18% fewer modern sea invertebrates than the Pliocene. The Miocene follows the Oligocene...

-age Vaqueros Sandstone formation, at a depth of between 2,000 to 2500 feet (762 m). The two oil accumulations were about two-thirds of a mile apart horizontally, and around the same depth. Trapping the oil was the overlying impermeable Rincon Shale
Rincon Formation
The Rincon Formation is a sedimentary geologic unit of Lower Miocene age, abundant in the coastal portions of southern Santa Barbara County, California eastward into Ventura County...

, also of Miocene age, and above that unit is the Monterey Formation
Monterey Formation
The Monterey Formation is an extensive Miocene oil-rich geological sedimentary formation in California, with massive outcroppings of the formation in areas of the California Coast Ranges, Peninsular Ranges, and on some of California's off-shore islands...

. A thin layer of Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....

 sediments known as the Santa Barbara Formation lies between the Monterey and ground surface. Underneath the Vaqueros formation and separated by an unconformity
Unconformity
An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...

 is the Oligocene
Oligocene
The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

-age Sespe Formation
Sespe Formation
The Sespe Formation is a widespread fossiliferous sedimentary geologic unit in southern and south central California in the United States. It is of nonmarine origin, consisting predominantly of sandstones and conglomerates laid down in a riverine, shoreline, and floodplain environment between the...

; no oil has been found in or beneath this unit, even though one well had been drilled into it to a total depth of over 10000 feet (3,048 m). The Sespe and Vaqueros Formations together form the second-most-prolific oil-producing unit in Southern California.

Oil from the Mesa field was medium to heavy. Early reports give a value of 17 to 18 degrees Baumé
Baumé scale
The Baumé scale is a pair of hydrometer scales developed by French pharmacist Antoine Baumé in 1768 to measure density of various liquids. The unit of the Baumé scale has been notated variously as degrees Baumé, B°, Bé° and simply Baumé . One scale measures the density of liquids heavier than water...

; the California Department of Natural Resources reports the same oil as having API gravity
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...

 of 20 to 24. Sulfur content was 0.45 percent. As its quality was relatively low, it was mainly used for fuel oil, road oil and asphalt.

Wells rarely produced for long, and a common experience of operators was fast production when the well first hit the oil-bearing sandstone, followed by swift decline, with late production mostly water. The overall structure of the field was imperfectly understood, with some wells producing poorly near to better producers; some geologists attributed such discrepancies to faulting
Geologic fault
In geology, a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement along the fractures as a result of earth movement. Large faults within the Earth's crust result from the action of tectonic forces...

 not visible in well cores, and others to impermeable sand lenses in the Vaqueros. Total recoverable oil was limited since oil appeared only in one relatively thin rock formation, and even the more productive wells became uneconomic to operate within a few years of their drilling.

History, production, and operations

The Mesa field was discovered during a time in California history when oil exploration and drilling was virtually unregulated. When oil was found it was typically developed to the maximum extent possible given the constraints of technology. Cities such as Los Angeles are built over numerous large oil fields, and smaller cities like Ventura
Ventura, California
Ventura is the county seat of Ventura County, California, United States, incorporated in 1866. The population was 106,433 at the 2010 census, up from 100,916 at the 2000 census. Ventura is accessible via U.S...

 and Santa Maria
Santa Maria, California
Santa Maria is a city in Santa Barbara County, on the Central Coast of California. The 2010 census population was 100,062, putting it ahead of Santa Barbara for the first time and making it the largest city in the county...

 grew with the petroleum industry being the primary economic driver. Santa Barbara alone of the cities in the region opposed the development of oil fields within its boundaries, with most of the population seeing the industry as incompatible with the town's character with regard to aesthetic and environmental values. In the 1890s and 1900s The Summerland Oil Field sprouted hundreds of oil derricks on the beach and along piers into the surf, just five miles (8 km) east of the Santa Barbara city boundary; its westward expansion occasioned a midnight raid by a party of vigilantes, led by Reginald Fernald, son of newspaper publisher Charles Fernald, who tore down one of the derricks that had just been built on Miramar Beach.

The first well drilled in the Mesa area was by Puritan Oil Co. in 1922, at 601 Flora Vista Drive. It was a wildcat well, and while not commercially viable and quickly abandoned, suggested to prospectors that it was worth looking more carefully for oil in the vicinity.

The discovery of the giant Ellwood Oil Field
Ellwood Oil Field
Ellwood Oil Field and South Ellwood Offshore Oil Field are a pair of adjacent, partially active oil fields adjoining the city of Goleta, California, about twelve miles west of Santa Barbara, largely in the Santa Barbara Channel...

 in 1929 in a similar geographic setting – a blufftop mesa twelve miles (19 km) west of Santa Barbara – commenced a frenzy of wildcat well drilling along the entire coastline from Carpinteria
Carpinteria, California
Carpinteria is a small oceanside city located in southeastern Santa Barbara County, California, east of Santa Barbara and northwest of Ventura. The population was 13,040 at the 2010 census, down from 14,194 at the 2000 census....

 to Gaviota
Gaviota, California
Gaviota is an unincorporated town in Santa Barbara County, California located about west of Santa Barbara and south of Buellton. Approximately 35 people live in and near Gaviota. The ZIP Code is 93117, and the community is inside area code 805....

. It was during this burst of activity that the discovery well for the Mesa field was put in, May 1929, by Olympic Refining Company in the Palisades residential tract, near the intersection of Mohawk Drive and Hudson Road. By the end of the summer, there were 31 oil wells in this small area, just recently subdivided into residential lots. These wells went dry quickly, and the area was abandoned by the next summer, having only produced 20909 barrels (3,324,265.4 l) of oil in all. However, residential construction stopped completely; wooden derricks sprung up on many of the small adjacent lots. The sight of these derricks, plainly visible from Santa Barbara harbor, occasioned the first anti-oil protest within the city of Santa Barbara, but since an ordinance had been enacted specifically allowing oil production on the Mesa, which had only recently been considered for residential development, the protests failed to stop drilling and development.

Three months after the abandonment of the Palisades area, in September 1930, drillers discovered the much more productive Vista del Oceano area, about two-thirds of a mile east of Palisades along Cliff Drive and on the hillside overlooking the Mesa and the ocean (hence the name). An even more productive area, Fair Acres, came online in March 1934 south of Cliff Drive, extending south across the Mesa all the way to the bluffs overlooking the beach. Sixty-five wells were drilled in the Fair Acres area by 1940. The most prolific producer was well "Cole No. 1" which flowed at an uncontrolled 1500 oilbbl/d into an open sump for two weeks, before being placed on production at around one-tenth of that rate. As the Fair Acres and Vista del Oceano areas are adjacent and not geological distinct, the California Department of Conservation lumps them together into a single area dubbed the "Main Area".

The Mesa field was entirely developed by small operators. As the land was subdivided into parcels before oil was discovered, it was a "town-lot" field, and parcel owners were able to drill on their own land without regard for the optimum spacing of wells on a field-wide basis (well spacing is now more tightly regulated in California). In 1934 there were 34 separate operators on 35 leases; the largest operator had only six wells.

Even the best-producing wells began to peter out by the late 1930s, and by 1940 only 22 wells out of 107 drilled were still producing, at an average rate of about 10 oilbbl/d. The field had not been particularly profitable. According to S.G. Dolman, writing in 1940, "... It is doubtful if the field has returned in dividends the money invested. Like most town-lot fields, there are 10 wells where one would have sufficed." Residential construction resumed after the Second World War, as wells were abandoned and sumps filled. The last well was capped in 1972 and the field formally abandoned in 1976.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK