API Well Number
A distinct 12-digit number assigned to a U.S. well. Digits 1 and 2 are state codes, 3-5 are county/parish or offshore codes, digits 6-10 identify the well and digits 11-12 identify special well conditions such as sidetracking.
How it’s important to us
The API # is a piece of data tracked almost universally through all well-centric applications and departments. Because it’s the government’s unique identifier, it is also a great way to link wells across systems. API stands for “American Petroleum Institute”. While the technical definition suggests that API # is unique, often the same 12-digit API prefix is used for and a 3-character “completion suffix” is tagged on when a well is re-completed.