Wellheads

Part of speech: noun

Definitions

1. An apparatus at the surface of a well for controlling the flow of oil, gas, or water from subterranean sources
2. A structure that provides access to the casing of a well while facilitating the extraction of resources like hydrocarbons
3. A mechanical installation designed to control pressure and allow the extraction of fluids from underground reservoirs

Etymology: "Wellheads" is the plural of "wellhead," a compound formed from "well" and "head." The "well" part is the older and more familiar element: a shaft sunk into the ground to reach water or another fluid, which has been a native English word since Old English. The "head" part here carries its sense of the top or source of something, as in the head of a river or the head of a spring, where water first emerges. Put together, the compound names the top of a well, the point where whatever lies underground reaches the surface. Over time the word narrowed from the simple wooden or stone top of a water well to the engineered equipment used in the oil and gas industry. Today a wellhead is a set of valves, fittings and pressure controls fixed to the top of a bore, and the plural names several such installations across a field.