The phrase "oil derricks" refers to tall structures used in the extraction of oil from deep underground. They are like big towers that have equipment to drill wells and pump out the oil. Full definition
1932 Against a bristling backdrop of oil derricks at Long Beach, Calif., Germany (left) defeated Italy in four - oared shells with cox for gold medal Meanwhile, in the Los Angeles Coliseum, Mildred (Babe) Didrikson (right), then just 18, won 80 - meter hurdles and javelin throw, finished second in the high jump. (si.com)
Black gold and Texas tea are what put Houston on the map, but if you visit Houston, you aren't going to look at oil derricks. (travelandleisure.com)
Heir to the testosterone cinema of Samuel Fuller and Nicholas Ray, Berg's films also find a kind of poetry in opposition, with Friday Night Lights» establishing shots of Texas's huge, glowering big sky country and insensate oil derricks pumping in silhouette set against the mayfly quickening of young men frozen for an instant that is, for many of them, meant to last a lifetime. (filmfreakcentral.net)