The Šamac oil field is an oil field located in Šamac.
 It was discovered in 2004 and developed by Energopetrol.
 The total proven reserves of the Šamac oil field are around 3.6 billion barrels (500×10tonnes), and production is supposed to be centered on 200000 oilbbl/d .
 If the information regarding this oil field is correct than it is the largest onshore oil field in Europe.
The Parshall Oil Field is an oil field producing from the Bakken Formation and Three Forks Formation near the town of Parshall, in Mountrail County, North Dakota.
 The field is in the Williston Basin.
 The field was discovered in 2006 by EOG Resources, which drilled, and now operates, most of the wells.
 It was the discovery of the Parshall Field that was largely responsible for the North Dakota oil boom.
 Parshall’s break-even price is at US$38/barrel, which is the lowest on the Bakken Formation; overall, Bakken’s break-even point is of US$62/barrel.
The South Belridge Oil Field is a large oil field in northwestern Kern County, San Joaquin Valley, California, about forty miles west of Bakersfield.
 Discovered in 1911, and having a cumulative production of over 1500 Moilbbl of oil at the end of 2008, it is the fourth-largest oil field in California, after the Midway-Sunset Oil Field, Kern River Oil Field, and Wilmington Oil Field, and is the sixth-most productive field in the United States.
 Its estimated remaining reserves, as of the end of 2008, were around 494 Moilbbl , the second-largest in the state, and it had 6,253 active wells.
 The principal operator on the field was Aera Energy LLC, a joint venture between Royal Dutch Shell and ExxonMobil.
 Additionally, the field included the only onshore wells in California owned and operated by ExxonMobil.
The North Dakota oil boom refers to the period of rapidly expanding oil extraction from the Bakken formation in the state of North Dakota that lasted from the discovery of Parshall Oil Field in 2006, and peaked in 2012, but with substantially less growth noted since 2015 due to a global decline in oil prices.
 Despite the Great Recession, the oil boom resulted in enough jobs to provide North Dakota with the lowest unemployment rate in the United States.
 The boom has given North Dakota, a state with a 2013 population of about 725,000, a billion-dollar budget surplus.
 North Dakota, which ranked 38th in per capita gross domestic product (GDP) in 2001, rose steadily with the Bakken boom, and now has per capita GDP 29% above the national average.
The Summerland Oil Field (and Summerland Offshore Oil Field) is an inactive oil field in Santa Barbara County, California, about four miles (6 km) east of the city of Santa Barbara, within and next to the unincorporated community of Summerland.
 First developed in the 1890s, and richly productive in the early 20th century, the Summerland Oil Field was the location of the world's first offshore oil wells, drilled from piers in 1896.
 This field, which was the first significant field to be developed in Santa Barbara County, produced 3.18 million of barrels of oil during its 50-year lifespan, finally being abandoned in 1939-40.
 Another nearby oil field entirely offshore, discovered in 1957 and named the Summerland Offshore Oil Field, produced from two drilling platforms in the Santa Barbara Channel before being abandoned in 1996.
The San Miguelito Oil Field is a large and currently productive oil field in the hills northwest of the city of Ventura in southern California in the United States.
 The field is close to the coastline, with U.S. Highway 101 running past at the base of the hills, and is sandwiched between the larger Ventura Oil Field to the east and the Rincon Oil Field, which is partially offshore, to the north and northwest.
 Discovered in 1931, and with about 7 million barrels of oil remaining out of its original 125 million, it ranks 44th in the state by size, and at the beginning of 2009 had 61 producing oil wells, all operated by Vintage Production California LLC, a subsidiary of Occidental Petroleum.
The Kern River Oil Field is a large oil field in Kern County in the San Joaquin Valley of California, north-northeast of Bakersfield in the lower Sierra foothills.
 Yielding a cumulative production of close to 2 Goilbbl of oil by the end of 2006, it is the third largest oil field in California, after the Midway-Sunset Oil Field and the Wilmington Oil Field, and the fifth largest in the United States.
 Its estimated remaining reserves, as of the end of 2006, were around 476 Moilbbl , the second largest in the state.
 It had 9,183 active wells, the second highest in the state.
 The principal operator on the field is Chevron Corporation
The Round Mountain Oil Field is a large oil and gas field in the foothills of the Sierra Nevada, about 10 mi northeast of Bakersfield, California, United States.
 It is east of the giant Kern River Oil Field, one of the largest in the United States, and also close to the Mount Poso Oil Field and Kern Front Oil Field.
 With a cumulative total recovery of more than 110 Moilbbl of oil, it is the 48th largest oil field in California, but remains relatively productive with still about ten percent of its reserves remaining in the ground, according to the California Department of Oil, Gas, and Geothermal Resources (DOGGR).
The Tweneboa Enyenra Ntomme Oil Field is an oil field within Ghana's territorial waters and the country's second major oil field after the Jubilee Oil Field.
 It is popularly known as the TEN oil field, an acronym formed from the three drilling fields that it comprises.
 Coincidentally, the exploration for oil in the basin also started with ten pre-first oil wells.
The Bakken Formation is a rock unit from the Late Devonian to Early Mississippian age occupying about 200000 sqmi of the subsurface of the Williston Basin, underlying parts of Montana, North Dakota, Saskatchewan and Manitoba.
 The formation was initially described by geologist J.W. Nordquist in 1953.
 The formation is entirely in the subsurface, and has no surface outcrop.
 It is named after Henry Bakken, a farmer in Tioga, North Dakota, who owned the land where the formation was initially discovered, during drilling for oil.

Question: The Parshall Oil Field is an oil field producing from a rock unit from the Late Devonian to Early Mississippian age occupying about how many sqmi?
Answer: 200000