Oilpatch

Near-synonyms: oil spot, oil slick

This minority establishes itself at the most vulnerable zone of the national territory, and then slowly spreads like an oilpatch, propagating itself in concentric ripples through the peasant masses, to the smaller towns, and finally to the capital.

Like many men of that era and region, he wandered into the oilpatch and worked as a roustabout for a while.

"Texas Oil Patch Songs": [...] Willet [...] sings a dozen of his own songs having to do with oil workers [...]

Fracturing the formation in the lingo of the oil patch is to perform a frac job.

"Alberta won't plug oilpatch"