Where the Ground Itself Proves Casing Matters.

The Wink Sinks — Water, Salt & Old Boreholes

Wink boomed on oil in the 1920s and gave the world Roy Orbison, who started his first band, the Wink Westerners, at the local high school. But the town's most striking landmark is underground: the Wink Sinks, two giant sinkholes just outside town.

Deep beneath Wink lie thick beds of Permian salt. When water finds its way down to that salt — and old, poorly-cased oil and gas boreholes gave it a path — the salt dissolves, a cavity grows, and eventually the surface collapses. The first sink opened in 1980; the second, in 2002, swallowed a water-supply well and pipelines and has grown to roughly 900 feet across.

It's the most vivid lesson in West Texas about why a well's casing and seal have to be right.