From Mr. John E. Fine:
I thought people would be interested in how an oil or gas well gets its identification numbers here in Texas. When a permit to drill is issued by the Texas Railroad Commission (RRC), it is assigned a permit number and also an API number.
API numbers are standardized system of numbering oil and gas wells in the United States where the first two numbers are the State (Texas is 42), followed by three representing the county. The county code is always an odd number. For example: 001 is Anderson County here in Texas. The next 5 numbers are the ID number for the well location within the County.
An API number never changes and is permanently attached to each well bore (historic wells being the only exception).
In Texas, when an oil well is completed and assigned to a field, it is given a 5 digit Lease number. Oil lease numbers are assigned sequentially within each RRC District. There are 12 Districts in Texas: 01, 02, 03, 04, 05, 06, 6E, 7B, 7C, 08, 8A, 09 and 10. A single lease can have hundreds of wells under one oil Lease number.
A gas well, on the other hand, is assigned a 6 digit number linked to that well only, and is sequentially independent of the RRC District it is in. Well bores can have multiple lease or ID numbers, each one
assigned to a particular producing reservoir.
I have worked among this system since the 1960's and there are exceptions to the rules. The regulation of the oil and gas industry has been an evolution of methods and terminology. Not too many people are
left who know how to navigate the old formats used in the 60's and
earlier.
President: Mason Map Service, Inc.