DISH, Texas—Twenty years ago this month, a well was drilled here that changed the world.

Nothing at the time suggested the unassuming well in this rural town north of Fort Worth would hobble OPEC, the powerful oil cartel that had governed prices of the world’s most important commodity for more than a generation. Or that it would help turn the U.S. into a global energy exporter, or shuffle the geopolitical deck.

But...