API Number
A unique 10- to 14-digit identifier assigned to every oil and gas well in the U.S., used to track its permits, production, and history.
The API number is the standard unique ID for an oil or gas well, set by the American Petroleum Institute and used by every state regulator. It encodes the state and county, then a unique well number — for example a Texas well begins with 42, the state code. Extra digits can identify a specific wellbore or sidetrack.
For anyone researching minerals, the API number is the master key. It ties together the drilling permit, spud and completion dates, production volumes, and operator changes across state databases like the Texas RRC or Oklahoma OCC. One number, one well, one complete history.
When you evaluate a tract, pulling every API number on and around it lets you reconstruct what has been drilled, what is producing, and what the rock is doing nearby.