Reference

Louisiana API county codes

Every Louisiana API well number starts with 17, the state code. The next three digits are the parish code, one of the 64 listed below, so a number beginning 17-001 belongs to a well in Acadia Parish.

To decode a whole number, including the sidetrack and completion digits, paste it into the API well number decoder.

How to read a Louisiana API number

17State: Louisiana
001Parish: Acadia
12345Well, unique within the parish

The first ten digits identify one well. Two more digits can follow for a sidetrack, and two after that for a later completion. The parish is the one where the well starts at the surface, so a horizontal well that crosses a parish line keeps its surface parish's code. A few state regulators assign the producing parish instead, so the state record is the final word on a well near a boundary.

All 64 Louisiana parishes

Parish code Parish API numbers start
001 Acadia 17-001-
003 Allen 17-003-
005 Ascension 17-005-
007 Assumption 17-007-
009 Avoyelles 17-009-
011 Beauregard 17-011-
013 Bienville 17-013-
015 Bossier 17-015-
017 Caddo 17-017-
019 Calcasieu 17-019-
021 Caldwell 17-021-
023 Cameron 17-023-
025 Catahoula 17-025-
027 Claiborne 17-027-
029 Concordia 17-029-
031 De Soto 17-031-
033 East Baton Rouge 17-033-
035 East Carroll 17-035-
037 East Feliciana 17-037-
039 Evangeline 17-039-
041 Franklin 17-041-
043 Grant 17-043-
045 Iberia 17-045-
047 Iberville 17-047-
049 Jackson 17-049-
051 Jefferson 17-051-
053 Jefferson Davis 17-053-
055 Lafayette 17-055-
057 Lafourche 17-057-
059 La Salle 17-059-
061 Lincoln 17-061-
063 Livingston 17-063-
065 Madison 17-065-
067 Morehouse 17-067-
069 Natchitoches 17-069-
071 Orleans 17-071-
073 Ouachita 17-073-
075 Plaquemines 17-075-
077 Pointe Coupee 17-077-
079 Rapides 17-079-
081 Red River 17-081-
083 Richland 17-083-
085 Sabine 17-085-
087 St. Bernard 17-087-
089 St. Charles 17-089-
091 St. Helena 17-091-
093 St. James 17-093-
095 St. John the Baptist 17-095-
097 St. Landry 17-097-
099 St. Martin 17-099-
101 St. Mary 17-101-
103 St. Tammany 17-103-
105 Tangipahoa 17-105-
107 Tensas 17-107-
109 Terrebonne 17-109-
111 Union 17-111-
113 Vermilion 17-113-
115 Vernon 17-115-
117 Washington 17-117-
119 Webster 17-119-
121 West Baton Rouge 17-121-
123 West Carroll 17-123-
125 West Feliciana 17-125-
127 Winn 17-127-

Parish names are the US Census names for these codes. The API standard does not promise the two match, so we checked them against state well records. Across 35 states, where this table names a parish it matched the one the agency recorded on 85,091 of 85,100 wells. Offshore state and federal waters use their own pseudo-county codes, which are not listed here.

Finding the well itself

The API number stops at the parish. It does not hold the well's coordinates, lease, survey section or operator. Those sit in the well record, which you find by searching the full number in the state agency's system. In Louisiana that is the SONRIS data portal, run by the Louisiana Department of Energy and Natural Resources (SONRIS).

Frequently asked questions

What is the API state code for Louisiana?

17. API state codes run alphabetically from 01 for Alabama to 49 for Wyoming, then 50 for Alaska and 51 for Hawaii. They are not the Census FIPS state codes, which is a common source of wrong lookups.

How do I find the parish from a Louisiana API number?

Read digits three to five and find them in the table on this page. In 17-001-12345, the parish code is 001, which is Acadia Parish. If the code is missing from the table, it is usually an offshore area rather than an onshore parish.

Does a Louisiana API number give the well's exact location?

No. The number stops at the parish. Coordinates, the lease and the survey location are in the well record held by the state agency, which you search with the full API number.

State codes: American Petroleum Institute Bulletin D12A well numbering standard. Parish names: US Census county FIPS names, checked against state well records. Reference generated .

How to cite this page

Sources: American Petroleum Institute Bulletin D12A well numbering standard; US Census county FIPS codes.

TetraSoft. (2026). Louisiana API county codes. Reference generated 2026-09-24. https://tetrasoftco.com/tools/api-county-codes/louisiana/