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85-640: Ellwood Oil Field (also spelled "Elwood") and South Ellwood Offshore Oil Field are a pair of adjacent, partially active oil fields adjoining the city of Goleta, California , about twelve miles (19 km) west of Santa Barbara , largely in the Santa Barbara Channel . A richly productive field in the 1930s, the Ellwood Oil Field was important to the economic development of the Santa Barbara area. A Japanese submarine shelled

170-445: A Japanese oil tanker, visited the field and tripped and fell into a patch of prickly pear cactus , provoking laughter from a group of nearby oil workers. The story says that Kozo came back a few years later, possibly for revenge. Kozo was a military service member who never worked on an oil tanker, as shown by Imperial Japanese Navy records that document his roles on submarines from the early 1920s through 1943. During World War II, Kozo

255-514: A blufftop mesa twelve miles (19 km) west of Santa Barbara – commenced a frenzy of wildcat well drilling along the entire coastline from Carpinteria to Gaviota . 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

340-445: A cap rock) is a fundamental part of the trap that prevents hydrocarbons from further upward migration. A capillary seal is formed when the capillary pressure across the pore throats is greater than or equal to the buoyancy pressure of the migrating hydrocarbons. They do not allow fluids to migrate across them until their integrity is disrupted, causing them to leak. There are two types of capillary seal whose classifications are based on

425-417: 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 not visible in well cores, and others to impermeable sand lenses in

510-406: A consequence, oil and natural gas are often found together. In common usage, deposits rich in oil are known as oil fields, and deposits rich in natural gas are called natural gas fields. In general, organic sediments buried in depths of 1,000 m to 6,000 m (at temperatures of 60 ° C to 150 °C) generate oil, while sediments buried deeper and at higher temperatures generate natural gas. The deeper

595-407: A few, very large offshore drilling rigs, due to the cost and logistical difficulties in working over water. Rising gas prices in the early 21st century encouraged drillers to revisit fields that previously were not considered economically viable. For example, in 2008 McMoran Exploration passed a drilling depth of over 32,000 feet (9754 m) (the deepest test well in the history of gas production) at

680-480: A gravity higher than 45 API. Gas cycling is the process where dry gas is injected and produced along with condensed liquid. Mesa Oil Field The Mesa Oil Field is an abandoned oil field entirely within the city limits of Santa Barbara, California , 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

765-595: A large pool in a zone of fractured shale at an average depth of 3,350 feet (1,020 m) below the ocean floor. Beneath that, a separate pool exists in the Rincon Sand, 5,000 feet (1,500 m) below the ocean floor, and yet another in the Vaqueros Formation at a depth of 5,900 feet (1,800 m). The deepest well drilled to date is 6,490 feet (1,980 m) into the Rincon Formation. This

850-684: 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 1,500 barrels per day (240 m /d) into an open sump for two weeks, before being placed on production at around one-tenth of that rate. As

935-524: A period of oil leasing and wildcat well drilling on the Santa Barbara south coast, from Carpinteria to Gaviota. During this period, the Mesa Oil Field was discovered, within the Santa Barbara city limits, about 12 miles (19 km) east of the Ellwood field. A local myth, which was told by local writer Walker A. Tompkins and others as fact, says that in the late 1930s, Kozo Nishino, the skipper of

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1020-471: A result of changes in the structure of the subsurface from processes such as folding and faulting , leading to the formation of domes , anticlines , and folds. Examples of this kind of trap are an anticline trap, a fault trap, and a salt dome trap. They are more easily delineated and more prospective than their stratigraphic counterparts, with the majority of the world's petroleum reserves being found in structural traps. Stratigraphic traps are formed as

1105-435: A result of lateral and vertical variations in the thickness, texture, porosity, or lithology of the reservoir rock. Examples of this type of trap are an unconformity trap, a lens trap and a reef trap. Hydrodynamic traps are a far less common type of trap. They are caused by the differences in water pressure, that are associated with water flow, creating a tilt of the hydrocarbon-water contact. The seal (also referred to as

1190-502: A significantly higher displacement pressure such that the pressure required for tension fracturing is actually lower than the pressure required for fluid displacement—for example, in evaporites or very tight shales. The rock will fracture when the pore pressure is greater than both its minimum stress and its tensile strength then reseal when the pressure reduces and the fractures close. Unconventional (oil & gas) reservoirs are accumulations where oil and gas phases are tightly bound to

1275-402: 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 acres (0.85 km ), and produced 3,700,000 barrels (590,000 m ) of oil during its brief lifetime. The field occupied a small area on a mesa to

1360-428: Is an economic benefit worthy of commercial attention. Oil fields may extend up to several hundred kilometers across the surface, meaning that extraction efforts can be large and spread out across the area. In addition to extraction equipment, there may be exploratory wells probing the edges to find more reservoir area, pipelines to transport the oil elsewhere, and support facilities. Oil fields can occur anywhere that

1445-402: Is analogous to saying that the oil which can be extracted forms within the source rock itself, as opposed to accumulating under a cap rock. Oil sands are an example of an unconventional oil reservoir. Unconventional reservoirs and their associated unconventional oil encompass a broad spectrum of petroleum extraction and refinement techniques, as well as many different sources. Since the oil

1530-403: Is being pursued at a higher rate because of the scarcity of conventional reservoirs around the world. After the discovery of a reservoir, a petroleum engineer will seek to build a better picture of the accumulation. In a simple textbook example of a uniform reservoir, the first stage is to conduct a seismic survey to determine the possible size of the trap. Appraisal wells can be used to determine

1615-452: Is best to manage the gas cap effectively, that is, placing the oil wells such that the gas cap will not reach them until the maximum amount of oil is produced. Also a high production rate may cause the gas to migrate downward into the production interval. In this case, over time the reservoir pressure depletion is not as steep as in the case of solution-based gas drive. In this case, the oil rate will not decline as steeply but will depend also on

1700-426: Is called the stock tank oil initially in place . As a result of studying factors such as the permeability of the rock (how easily fluids can flow through the rock) and possible drive mechanisms, it is possible to estimate the recovery factor, or what proportion of oil in place can be reasonably expected to be produced. The recovery factor is commonly 30–35%, giving a value for the recoverable resources. The difficulty

1785-490: Is contained within the source rock, unconventional reservoirs require that the extracting entity function as a mining operation rather than drilling and pumping like a conventional reservoir. This has tradeoffs, with higher post-production costs associated with complete and clean extraction of oil being a factor of consideration for a company interested in pursuing a reservoir. Tailings are also left behind, increasing cleanup costs. Despite these tradeoffs, unconventional oil

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1870-498: Is entirely within the State Tidelands zone, which encompasses areas within three nautical miles (5.6 km) of shore. These regions are subject to state, rather than Federal regulation. The last production from this field was from Platform Holly, which is in 211 feet (64 m) of water, about two miles (3.2 km) from the coast at Coal Oil Point and has been shut down. Numerous directionally-drilled oil wells originate at

1955-431: Is more accurate to divide the oil industry into three sectors: upstream ( crude oil production from wells and separation of water from oil ), midstream (pipeline and tanker transport of crude oil) and downstream ( refining of crude oil to products, marketing of refined products, and transportation to oil stations). More than 65,000 oil fields are scattered around the globe, on land and offshore. The largest are

2040-649: Is shared between Iran and Qatar . The second largest natural gas field is the Urengoy gas field , and the third largest is the Yamburg gas field , both in Russia . Like oil, natural gas is often found underwater in offshore gas fields such as the North Sea , Corrib Gas Field off Ireland , and near Sable Island . The technology to extract and transport offshore natural gas is different from land-based fields. It uses

2125-413: Is that reservoirs are not uniform. They have variable porosities and permeabilities and may be compartmentalized, with fractures and faults breaking them up and complicating fluid flow. For this reason, computer modeling of economically viable reservoirs is often carried out. Geologists, geophysicists, and reservoir engineers work together to build a model that allows simulation of the flow of fluids in

2210-771: Is the Monterey Formation . A thin layer of Pleistocene sediments known as the Santa Barbara Formation lies between the Monterey and ground surface. Underneath the Vaqueros formation and separated by an unconformity is the Oligocene -age Sespe Formation ; 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 10,000 feet (3,000 m). The Sespe and Vaqueros Formations together form

2295-940: Is usually necessary to drill into the Earth's crust, although surface oil seeps exist in some parts of the world, such as the La Brea Tar Pits in California and numerous seeps in Trinidad . Factors that affect the quantity of recoverable hydrocarbons in a reservoir include the fluid distribution in the reservoir, initial volumes of fluids in place, reservoir pressure, fluid and rock properties, reservoir geometry, well type, well count, well placement, development concept, and operating philosophy. Modern production includes thermal , gas injection , and chemical methods of extraction to enhance oil recovery. A virgin reservoir may be under sufficient pressure to push hydrocarbons to

2380-555: Is year-round. Numerous other oil fields exist within the region. The Summerland Oil Field , 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 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

2465-475: The 1969 Santa Barbara oil spill . The structure of the Mesa field is relatively simple. Oil was trapped in two anticlinal structures in a band of the porous Miocene -age Vaqueros Sandstone formation , at a depth of between 2,000 and 2,500 feet (760 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 , also of Miocene age, and above that unit

2550-634: The Ghawar Field in Saudi Arabia and the Burgan Field in Kuwait , with more than 66 to 104 billion barrels (9.5×10 m ) estimated in each. In the modern age, the location of oil fields with proven oil reserves is a key underlying factor in many geopolitical conflicts. Natural gas originates by the same geological thermal cracking process that converts kerogen to petroleum. As

2635-560: The aquatic ecosystem , which is usually a sea but might also be a river, lake, coral reef, or algal mat , the formation of an oil or gas reservoir also requires a sedimentary basin that passes through four steps: Timing is also an important consideration; it is suggested that the Ohio River Valley could have had as much oil as the Middle East at one time, but that it escaped due to a lack of traps. The North Sea , on

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2720-407: The buoyancy forces driving the upward migration of hydrocarbons through a permeable rock cannot overcome the capillary forces of a sealing medium. The timing of trap formation relative to that of petroleum generation and migration is crucial to ensuring a reservoir can form. Petroleum geologists broadly classify traps into three categories that are based on their geological characteristics:

2805-591: The 1960s. The onshore portion was abandoned in 1972. The site of the oilfield equipment damaged by the Japanese is Santa Barbara County property, which may be traversed by the public, on the beach below the Sandpiper Golf Course. A historical marker on a rock on the Golf Course grounds recounts the Japanese attack. The existence of an offshore field was suspected for a long time, largely due to

2890-671: The Blackbeard site in the Gulf of Mexico. ExxonMobil 's drill rig there had reached 30,000 feet by 2006, without finding gas, before it abandoned the site. Crude oil is found in all oil reservoirs formed in the Earth's crust from the remains of once-living things. Evidence indicates that millions of years of heat and pressure changed the remains of microscopic plants and animals into oil and natural gas. Roy Nurmi, an interpretation adviser for Schlumberger oil field services company, described

2975-564: The Ellwood field was generally light and sweet , with an API gravity averaging 38 and low sulfur content (making it "sweet" in petroleum parlance). Oil from the offshore field is medium-grade, ranging from API gravity 25 to 34, and has a higher sulfur content, requiring more processing than the oil from the decommissioned onshore field. Several pools have been identified in the South Ellwood Offshore field, in three major vertical zones. The upper Monterey Formation contains

3060-543: The Fair Acres and Vista del Oceano areas are adjacent and not geologically 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

3145-484: 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. 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

3230-404: The abandoned and earthquake-damaged "Dibblee Castle" built at the eastern end, overlooking Santa Barbara harbor. Climate in the area is Mediterranean , with mild, sometimes rainy winters and dry summers, with the temperature moderated by ocean breezes and a morning marine layer . Freezes are extremely rare. Mean annual temperature is approximately 60 °F (16 °C), and the growing season

3315-410: The actual capacity. Laboratory testing can determine the characteristics of the reservoir fluids, particularly the expansion factor of the oil, or how much the oil expands when brought from the high pressure and high temperature of the reservoir to a "stock tank" at the surface. With such information, it is possible to estimate how many "stock tank" barrels of oil are located in the reservoir. Such oil

3400-602: The area during World War II . It was the first direct naval bombardment of the continental U.S. since the Civil War, causing an invasion scare on the West Coast. The Ellwood Oil Field is located approximately 12 miles (19 km) west of the city of Santa Barbara, beginning at the western boundary of the city of Goleta, proceeding west into the Pacific and then back onshore near Dos Pueblos Ranch . The onshore portions of

3485-399: The constraints of technology. Cities such as Los Angeles are built over numerous large oil fields, and smaller cities like Ventura and Santa Maria 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

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3570-485: The decrease in reservoir pressure from the oil and gas produced at the platform. Away from Platform Holly, much of the field is still not fully explored and developed. Mobil's 1995 proposal to drill from the shore (the "Clearview" project, dubbed "Drillview" by opponents) was rejected, and a proposal to drill into the more distant parts of the field from the existing Platform Holly was under consideration in 2009. The proposal involved directionally drilling 40 new wells from

3655-573: The degree possible with the technology available until the early 1970s. The field now has been abandoned. The South Ellwood Offshore field has been estimated by the US Department of Energy to hold over one billion barrels of oil and approximately 2.1 billion barrels (330,000,000 m), most of which is in the undeveloped portion of the field. In 1995, the Oil and Gas Journal reported 155 million barrels (24,600,000 m) of proven reserves. Oil from

3740-422: 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 in 1929 in a similar geographic setting –

3825-578: The existing platform, potentially tripling its production. Platform Holly has been inactive since the Refugio Oil Spill in May 2015 ruptured the pipeline it relies on to transport oil to market. Venoco has since filed bankruptcy , and the platform is being decommissioned. Ownership of the platform has been transferred to the state, which is now responsible for removal of the structure. The California State Lands Commission work to plug and abandon

3910-595: The field include beach, coastal bluffs, blufftop grasslands, and eucalyptus groves. Some of the former oil field is now part of the Ellwood-Devereux Open Space, maintained by the city of Goleta, and the Bacara Resort, Sandpiper Golf Course, and new Goleta housing developments sit on areas formerly occupied by pump-jacks, derricks, and oil storage tanks. The climate is Mediterranean , with an equable temperature regime year-round, and most of

3995-498: 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

4080-402: The gas bubbles drive the oil to the surface. The bubbles then reach critical saturation and flow together as a single gas phase. Beyond this point and below this pressure, the gas phase flows out more rapidly than the oil because of its lowered viscosity. More free gas is produced, and eventually the energy source is depleted. In some cases depending on the geology the gas may migrate to the top of

4165-407: The geology of the underlying rock allows, meaning that certain fields can be far away from civilization, including at sea. Creating an operation at an oil field can be a logistically complex undertaking, as it involves the equipment associated with extraction and transportation, as well as infrastructure such as roads and housing for workers. This infrastructure has to be designed with the lifespan of

4250-434: The liquid sections applying extra pressure. This is present in the reservoir if there is more gas than can be dissolved in the reservoir. The gas will often migrate to the crest of the structure. It is compressed on top of the oil reserve, as the oil is produced the cap helps to push the oil out. Over time the gas cap moves down and infiltrates the oil, and the well will produce more and more gas until it produces only gas. It

4335-438: The location of oil-water contact and with it the height of the oil bearing sands. Often coupled with seismic data, it is possible to estimate the volume of an oil-bearing reservoir. The next step is to use information from appraisal wells to estimate the porosity of the rock. The porosity of an oil field, or the percentage of the total volume that contains fluids rather than solid rock, is 20–35% or less. It can give information on

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4420-682: The northeast. Oil occurs in several pools, with the largest being in the Vaqueros Sandstone , approximately 3,400 feet (1,000 m) below ground surface. Other significant pools occur in the Rincon Formation at a depth of 2,600 feet (790 m), and in the Upper Sespe Formation at 3,700 feet (1,100 m) below ground surface. The Ellwood Oil Field contained approximately 106 million barrels (16,900,000 m) of oil, almost all of which has been removed, to

4505-438: The oil and form a secondary gas cap. Some energy may be supplied by water, gas in water, or compressed rock. These are usually minor contributions with respect to hydrocarbon expansion. By properly managing the production rates, greater benefits can be had from solution-gas drives. Secondary recovery involves the injection of gas or water to maintain reservoir pressure. The gas/oil ratio and the oil production rate are stable until

4590-436: The oil field in mind, as production can last many years. Several companies, such as Hill International , Bechtel , Esso , Weatherford International , Schlumberger , Baker Hughes and Halliburton , have organizations that specialize in the large-scale construction of the infrastructure to support oil field exploitation. The term "oilfield" can be used as a shorthand to refer to the entire petroleum industry . However, it

4675-742: The oil fields, Ellwood Canyon, Ellwood School, Ellwood Station Road, and the Goleta neighborhood "Ellwood". The first oil discovery in the area was in July 1928, by Barnsdall Oil Co. of California and the Rio Grande Company, who drilled their Luton-Bell Well No. 1 to a depth of 3,208 feet (978 m) into the Vaqueros Sandstone. After almost giving up they not only struck oil, but had a significant gusher, initially producing 1,316 barrels per day (209.2 m/d). This discovery touched off

4760-571: 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 barrels per day (1.6 m /d). The field had not been particularly profitable. According to S.G. Dolman, writing in 1940, "... It

4845-724: The other hand, endured millions of years of sea level changes that successfully resulted in the formation of more than 150 oil fields. Although the process is generally the same, various environmental factors lead to the creation of a wide variety of reservoirs. Reservoirs exist anywhere from the land surface to 30,000 ft (9,000 m) below the surface and are a variety of shapes, sizes, and ages. In recent years, igneous reservoirs have become an important new field of oil exploration, especially in trachyte and basalt formations. These two types of reservoirs differ in oil content and physical properties like fracture connectivity, pore connectivity, and rock porosity . A trap forms when

4930-408: The persistent natural seepage of oil from the sea floor. The Coal Oil Point seep field is now one of the most actively studied seep zones in the world. In 1966, ARCO built Platform Holly, in 211 feet (64 m) of water approximately two miles (3.2 km) southwest of Coal Oil Point, and began drilling wells into the various zones in the South Ellwood Offshore field. Peak production from the field

5015-406: The placement of the well with respect to the gas cap. As with other drive mechanisms, water or gas injection can be used to maintain reservoir pressure. When a gas cap is coupled with water influx, the recovery mechanism can be highly efficient. Water (usually salty) may be present below the hydrocarbons. Water, as with all liquids, is compressible to a small degree. As the hydrocarbons are depleted,

5100-416: The platform, and several pipelines connect the platform to an onshore oil processing facility adjacent to the Sandpiper Golf Course. The Ellwood Oil Field is roughly five miles (8.0 km) long and up to a mile wide, with both its eastern and western extremity onshore. It is an anticlinal structure, with oil trapped stratigraphically by the anticline. The More Ranch Fault provides an impermeable barrier on

5185-474: The precipitation falling between October and April in the form of rain. Freezes are rare. Runoff is towards the ocean, and to a few vernal pools on the bluffs. The offshore portions of the Ellwood oil field are in relatively shallow water, and were drilled from piers. The South Ellwood Offshore field is entirely beneath the Pacific Ocean, about two miles (3.2 km) from the main onshore oil field. It

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5270-431: The preferential mechanism of leaking: the hydraulic seal and the membrane seal. A membrane seal will leak whenever the pressure differential across the seal exceeds the threshold displacement pressure, allowing fluids to migrate through the pore spaces in the seal. It will leak just enough to bring the pressure differential below that of the displacement pressure and will reseal. A hydraulic seal occurs in rocks that have

5355-429: The pressure. As the reservoir depletes, the pressure falls below the bubble point , and the gas comes out of solution to form a gas cap at the top. This gas cap pushes down on the liquid helping to maintain pressure. This occurs when the natural gas is in a cap below the oil. When the well is drilled the lowered pressure above means that the oil expands. As the pressure is reduced it reaches bubble point, and subsequently

5440-485: The process as follows: Plankton and algae, proteins and the life that's floating in the sea, as it dies, falls to the bottom, and these organisms are going to be the source of our oil and gas. When they're buried with the accumulating sediment and reach an adequate temperature, something above 50 to 70 °C they start to cook. This transformation, this change, changes them into the liquid hydrocarbons that move and migrate, will become our oil and gas reservoir. In addition to

5525-491: The reduction in pressure in the reservoir allows the water to expand slightly. Although this unit expansion is minute, if the aquifer is large enough this will translate into a large increase in volume, which will push up on the hydrocarbons, maintaining pressure. With a water-drive reservoir, the decline in reservoir pressure is very slight; in some cases, the reservoir pressure may remain unchanged. The gas/oil ratio also remains stable. The oil rate will remain fairly stable until

5610-408: The reservoir pressure drops below the bubble point when critical gas saturation is reached. When the gas is exhausted, the gas/oil ratio and the oil rate drops, the reservoir pressure has been reduced, and the reservoir energy is exhausted. In reservoirs already having a gas cap (the virgin pressure is already below bubble point), the gas cap expands with the depletion of the reservoir, pushing down on

5695-409: The reservoir, leading to an improved estimate of the recoverable resources. Reserves are only the part of those recoverable resources that will be developed through identified and approved development projects. Because the evaluation of reserves has a direct impact on the company or the asset value, it usually follows a strict set of rules or guidelines. To obtain the contents of the oil reservoir, it

5780-410: The rock fabric by strong capillary forces, requiring specialised measures for evaluation and extraction. Unconventional reservoirs form in completely different ways to conventional reservoirs, the main difference being that they do not have "traps". This type of reservoir can be driven in a unique way as well, as buoyancy might not be the driving force for oil and gas accumulation in such reservoirs. This

5865-419: The rocks have high porosity and low permeability, which keeps the hydrocarbons trapped in place, therefore not requiring a cap rock . Reservoirs are found using hydrocarbon exploration methods. An oil field is an area of accumulated liquid petroleum underground in multiple (potentially linked) reservoirs, trapped as it rises to impermeable rock formations. In industrial terms, an oil field implies that there

5950-512: 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 ; the California Department of Natural Resources reports the same oil as having API gravity 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

6035-410: The source, the "drier" the gas (that is, the smaller the proportion of condensates in the gas). Because both oil and natural gas are lighter than water, they tend to rise from their sources until they either seep to the surface or are trapped by a non-permeable stratigraphic trap. They can be extracted from the trap by drilling. The largest natural gas field is South Pars/Asalouyeh gas field, which

6120-430: 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 (37 m) above the beach at the western end of the mesa, gradually diminishing in height to only 40 feet (12 m) at the eastern end, near Santa Barbara City College . Prior to the oil field being developed, the flat top of the mesa was farmland, with one imposing former residence,

6205-454: The structural trap, the stratigraphic trap, and the far less common hydrodynamic trap . The trapping mechanisms for many petroleum reservoirs have characteristics from several categories and can be known as a combination trap. Traps are described as structural traps (in deformed strata such as folds and faults) or stratigraphic traps (in areas where rock types change, such as unconformities, pinch-outs and reefs). Structural traps are formed as

6290-450: 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 20,909 barrels (3,324.3 m ) 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

6375-452: The surface. As the fluids are produced, the pressure will often decline, and production will falter. The reservoir may respond to the withdrawal of fluid in a way that tends to maintain the pressure. Artificial drive methods may be necessary. This mechanism (also known as depletion drive) depends on the associated gas of the oil. The virgin reservoir may be entirely semi-liquid but will be expected to have gaseous hydrocarbons in solution due to

6460-436: 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 (8.0 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

6545-407: The water begins to be produced along with the oil, the recovery rate may become uneconomical owing to the higher lifting and water disposal costs. If the natural drives are insufficient, as they very often are, then the pressure can be artificially maintained by injecting water into the aquifer or gas into the gas cap. The force of gravity will cause the oil to move downward of the gas and upward of

6630-431: The water reaches the well. In time, the water cut will increase, and the well will be watered out. The water may be present in an aquifer (but rarely one replenished with surface water ). This water gradually replaces the volume of oil and gas that is produced out of the well, given that the production rate is equivalent to the aquifer activity. That is, the aquifer is being replenished from some natural water influx. If

6715-442: The water. If vertical permeability exists then recovery rates may be even better. These occur if the reservoir conditions allow the hydrocarbons to exist as a gas. Retrieval is a matter of gas expansion. Recovery from a closed reservoir (i.e., no water drive) is very good, especially if bottom hole pressure is reduced to a minimum (usually done with compressors at the wellhead). Any produced liquids are light-colored to colorless, with

6800-550: The water. One of the explosions damaged well Luton-Bell 17, on the beach just below Fairway 14 of the present-day golf course, causing about $ 500 in damage to a catwalk and some pumping equipment. Kozo radioed Tokyo that he had "left Santa Barbara in flames." This incident was the first direct naval bombardment by an enemy power on the U.S. continent since the bombardment of Orleans in World War I. The Ellwood field reached peak production in 1930, but it remained productive through

6885-516: The wells began in 2019, with an estimated two to three years until completion. 34°25′26″N 119°55′34″W  /  34.424°N 119.926°W  / 34.424; -119.926 Oil field Reservoirs are broadly classified as conventional and unconventional reservoirs. In conventional reservoirs, the naturally occurring hydrocarbons, such as crude oil ( petroleum ) or natural gas , are trapped by overlying rock formations with lower permeability , while in unconventional reservoirs

6970-549: 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 from which the neighborhood takes its name is about two miles (3.2 km) long from west to east and about 3,000 feet (910 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

7055-471: Was a short-lived oil field which produced for only 13 months before water appeared in the wells. Production ceased by Feb. 1928. Miley Oil Company drilled the No. Goleta 1 discovery well, with oil shows at 613 and 1,527 feet. The field is named for Ellwood Cooper (1829-1918), who owned the large Ellwood Ranch in what is now Goleta and the adjacent hills. His first name lingers in several local place names including

7140-414: Was captain of Japanese submarine I-17 , which surfaced just off of Coal Oil Point on the evening of February 23, 1942. His crew emerged and manned the sub's 5.5" deck gun . They fired between 16 and 25 rounds at a pair of oil storage tanks near where he had fallen into the cactus. His gunners were poor shots, and most of the shells went wild, exploding either miles inland on Tecolote Ranch, or splashing in

7225-461: Was in 1984. Mobil operated Platform Holly until 1997, when Venoco acquired all rights to the field. Three pipelines – one oil, one gas, and one for utilities – connected the platform to the processing plant on the mainland. In addition, an oil pipeline transported oil from "tents" constructed over some of the natural seeps on the ocean floor to the processing plant. Leakage from the natural seeps near Platform Holly decreased substantially, probably from

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