strike oil

Verb

strike oil (third-person singular simple present strikes oil, present participle striking oil, simple past struck oil, past participle struck oil or (rare or archaic) stricken oil)

1. To find petroleum when boring for it.
   • In today's oil patch you strike oil the modern way – the geologist examines the rock cuttings brought up in the drilling mud to see if there is any oil on them as John had done here.2015, Mike Shepherd, Oil Strike North Sea: A first-hand history of North Sea oil, Luath Press Ltd, →ISBN
2. (figuratively, idiomatic, informal) To have sudden good fortune, especially financially.
   • J. Paul Getty's formula for success sorts this idea out: “Rise early, work hard, strike oil.” That's good advice, but most of us will not strike oil. In fact we may become irritated by the idea that something spectacular must occur for success to emerge.2002, R. Wayne Pace, Organizational Dynamism: Unleashing Power in the Workforce, Greenwood Publishing Group, →ISBN, page 4