API Number

An API Number is a unique number which identifies each specific well which is drilled in the United States. The API numbering system was developed by the American Petroleum Institute (API) as a method of identifying each particular well. Generally, an API number will have a up to 14 digits in which the first two digits represent the state code followed by three digits representing the county code. The next five digits indicate the identifying number specific to the well. An additional two digits represent any sidetrack to the well followed by an additional two digits indicating an additional sequence of events. The first two API code digits for wells drilled onshore in Texas is 42 established by the Texas Railroad Commission.