A number issued by the Division of Oil and Gas (DOG) to identify wells and/or well operations. Permit Numbers have been used inconsistently over the years, rendering them unsuitable as unique well identifiers. Consequently, the IGS uses its own unique IGS ID to identify well locations.
Wells Events are arbitrarily assigned the Permit Number "0" by the IGS if for any reason they were not issued a Permit Number when the event occurred. Thousands of wells in Indiana drilled prior to 1938, the year petroleum drilling permits were first issued, fall into this category. A relatively small number of wells drilled since 1938 also did not have Permit Numbers issued.
A single IGS ID Number may be associated with multiple Permit Numbers, but with only one well (one surface location).
In the PDMS, Permit Numbers may contain letters as well as numbers, although this may differ from official usage used by DOG. For instance, DOG permit number 12850 was issued in 1952 for multiple stratigraphic tests in LaGrange County. The permit covers 89 drilled wells. In the PDMS, each well is assigned a unique IGS ID number and the Permit Number is prefixed by the letters CST, for "County Stratigraphic Test" (officially termed "Stratigraphic/Structure Test"). The letters help to clarify that multiple wells were drilled under a single Permit Number. When using the search function in the PDMS, it is not necessary to include the letters; the same records will be returned in either case.
Caution: DOG sometimes uses the Permit Number in the IGS ID Number field in their online Well Records Search. This informal substitution is made when DOG scans a well record and the true IGS ID Number for that record is not readily apparent. The determination of which IGS ID number to associate with a particular permit number is simply deferred by using the Permit Number in place of the IGS ID.