Spraberry Trend
The Spraberry Trend (also known as the Spraberry Field, Spraberry Oil Field, and Spraberry Formation) is a large oil field in the Permian Basin of west central Texas, covering large parts of six counties, and having a total area of approximately 2,500 square miles (6,500 km2). It is named for Abner Spraberry, the Dawson County farmer who owned the land containing the 1943 discovery well. The Spraberry Trend is itself part of a larger oil-producing region known as the Spraberry-Dean Play, within the Midland Basin. Discovery and development of the field began the postwar economic boom in the nearby city of Midland in the early 1950s. The oil in the Spraberry, however, proved difficult to recover. After about three years of enthusiastic drilling, during which most of the initially promising wells showed precipitous and mysterious production declines, the area was dubbed "the world's largest unrecoverable oil reserve."
In 2007, the U.S. Department of Energy ranked The Spraberry Trend third in the United States by total proved reserves, and seventh in total production. Estimated reserves for the entire Spraberry-Dean unit exceed 10 billion barrels (1.6×109 m3), and by the end of 1994 the field had reported a total production of 924 million barrels (146,900,000 m3).
The Spraberry Trend covers a large area – around 2,500 square miles (6,500 km2) – and includes portions of two Texas geographical regions, the Llano Estacado and the Edwards Plateau. As most often defined, the Spraberry includes portions of Irion, Reagan, Upton, Glasscock, Midland, and Martin Counties, although the underlying geologic unit also touches Dawson, Crockett, and Andrews Counties. Elevations are generally between 2,500 and 3,000 feet (910 m) above sea level, and the terrain varies from flat to rolling, with occasional canyons, known locally as "draws", cutting through the plateau. Drainage is to the east, via the Concho River to the Colorado River. The climate is semi-arid. Native vegetation includes scrub and grasslands, with trees such as cottonwoods along the watercourses.
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