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The Coalinga Oil Field is a large oil field in western Fresno County, California, in the United States. It surrounds the town of Coalinga, about half-way between Los Angeles and San Francisco, to the west of Interstate 5, at the foot of the Diablo Range. Discovered in the late 19th century, it became active around 1890, and is now the eighth-largest oil field in California, with reserves totaling approximately 58 million barrels (9,200,000 m3), and over 1,600 active oil wells. The principal operators on the field, as of 2008, were Chevron Corp. (formerly Standard Oil of California or SoCal) and Aera Energy LLC.Oil was known in the Coalinga area long before the arrival of Europeans, as the native Americans in the region used the tarry substance from natural seeps as lining for baskets, as well as for trade. The first attempt to drill for oil was in 1867, but success was limited both due to the difficulty of transporting oil at the time, and the relative disinterest in petroleum prior to the era of motorized transport.
In 1890 the first oil boom began, once the Southern Pacific had extended its rail line into the town of Coalinga. Around the “Oil City” area of the Coalinga Field, directly north of the modern-day town of Coalinga, several large gushers attracted attention, gushers still being a relatively new occurrence in the oil industry. The “Blue Goose” well, drilled by the Home Oil Company to a depth 1,400 feet (430 m), erupted in 1898, spewing over 1,000 barrels per day (160 m3/d).
The huge and productive Temblor oil pools were discovered around 1900, and by 1910 the field was the most richly productive oil field in California, exceeding those in the Los Angeles Basin for the first time. A dramatic oil gusher in 1909 at the “Silver Tip” well, the biggest gusher in California until then, was an event of such excitement that Los Angeles Stock Exchange closed down for a day so that its members could come by train to view it. This gusher would be dwarfed a year later by the colossal Lakeview Gusher, by which California’s largest oil field, the Midway-Sunset in Kern County, was first known.
In the early years of the field, competition was fierce between different oil companies, with a particularly sharp conflict between a group of independent oil producers and Standard Oil, which operated as a gigantic trust until its breakup by the U.S. Supreme Court in 1911. According to an article published in the New York Times in 1905, Standard attempted to force its competitors out of business by artificially holding down the price of oil to as little as ten cents a barrel. The Coalinga independents responded by building a pipeline to San Francisco Bay, the construction of which was itself obstructed by continuous harassment from Standard, until the independents were finally successful by ruse: secretly building a real pipeline, while simultaneously seeming to work on a “dummy” pipeline in a more prominent location. During this time, the independent operators also accused the Southern Pacific Railroad of working in conjunction with Standard to put them out of business.
The operators of the Coalinga field attained peak production in 1912 – 19,500,000 barrels (3,100,000 m3) of oil – a value which was to decline steadily for the next several decades.
During the 1960s and 1970s, enhanced recovery technologies such as water flooding, steam flooding, fire flooding, and polymer flooding were employed to increase the declining productivity of the field, and to reach and recover previously submarginal deposits. Even with such methods, the current oil output of the field has declined considerably from the early part of the 20th century: in 2006, the field’s operators reported 5,700,000 barrels (906,000 m3) of oil pumped.
A pumpjack (nodding donkey, pumping unit, horsehead pump, beam pump, sucker rod pump (SRP), grasshopper pump, thirsty bird, jack pump) is the overground drive for a reciprocating piston pump in an oil well.
It is used to mechanically lift liquid out of the well if there is not enough bottom hole pressure for the liquid to flow all the way to the surface. The arrangement is commonly used for onshore wells producing little oil. Pumpjacks are common in oil-rich areas.
Depending on the size of the pump, it generally produces 5 to 40 litres of liquid at each stroke. Often this is an emulsion of crude oil and water. Pump size is also determined by the depth and weight of the oil to remove, with deeper extraction requiring more power to move the heavier lengths of sucker rods.