The API (American Petroleum Institute) number is a unique number assigned to every oil and gas well. It is used by agencies to identify and track oil and gas wells. Every oil and gas well permitted in West Virginia since 1929 has been issued an API number. The API number is required to be posted on every oil and gas well. If you have a question about a particular well, it is very helpful if you know the API number of that well.
The API number has the following format:
47 = State code. 47 is the state code for West Virginia. All API’s in WV will begin with 47.
001 = The next three digits are the County Code. County codes are odd numbers, beginning with 001 (Barbour) continuing, alphabetically, to 109 (Wyoming). The list of county codes is below.
00001 = Well number. Each well will have a unique well number. Well numbers are ordered sequentially by the order they are issued. The smaller the number, the older the well.
4700100001 – The first API number issued in Barbour County.
4709502000 – The 2,000th API number issued in Tyler County.
Exceptions and Practices
Over the years, different practices have developed concerning API numbers. Within West Virginia, historically the 47 state code was often dropped. Also, some computer systems and databases dropped the leading “0” county codes. The hyphens have sometimes been used in various systems. The examples below show these uses. All represent the same well.
47-085-01250 = A Ritchie county well with full API number.
4708501250 = The same well, no hyphens.
085-01250 = The same well, state code has been dropped.
85-01250 = The same well, leading “0” dropped.
8501250 = The same well, leading “0” and hyphen dropped.
The WV DEP has standardized the API number and will use the full 10-digit API for correspondence concerning wells.