What is an API well number?

An API well number is the unique identifier assigned to every oil and gas well drilled in the United States, issued under the American Petroleum Institute numbering standard. The full standardised form is 14 digits: a 2-digit state code, a 3-digit county code, a 5-digit unique well number, a 2-digit directional sidetrack code and a 2-digit event code.

How do I look up a well by its API number?

Type the API number into the search box above. Dashes are optional. You need at least the first 10 digits — shorter prefixes are rejected because a partial county prefix would match thousands of unrelated wells.

Can I search for wells by operator name?

Yes. Enter an operator name such as ROCKIES RESOURCES, or a well name, and the lookup will return matching wells. Name searches need at least 3 characters. You can narrow the results with an optional 2-letter state code.

Is this well API number search free?

Yes. The lookup requires no account and no API key. A free search returns up to 5 wells, alongside the total number of wells that matched, and results are not sorted by recency.

Why are coordinates and legal location hidden?

Surface coordinates and legal location (township and range) are included with Drilling Intelligence access. Where the lookup shows a dash instead of a locked badge, we simply do not hold that field for that well — not every state regulator publishes it.

Where does this well data come from?

State oil and gas commission permit filings, which are public records at the source. What this service adds is aggregation across 27 US states and 3 Canadian provinces, daily refresh, and a single schema in place of thirty separate state websites.

Does one row mean one permit?

No. The registry holds one record per well, keyed on its API number — 2,292,533 records against 2,292,533 distinct API numbers. It is not a permit-event history, so repeat filings on the same well are not represented as separate rows.

2.2M+ well records | 27 US states | free, no account

Well API Number Lookup — Free Search

Look up US oil and gas wells by operator name, well name, or 14-digit API well number. One record per well, drawn from state oil and gas commission filings and refreshed daily.

How to read a 14-digit API well number

State and county

The first 2 digits identify the state (42 = Texas, 35 = Oklahoma, 33 = North Dakota). The next 3 identify the county or parish.

Unique well number

Digits 6 through 10 are the unique well identifier within that county. These 10 digits are the shortest prefix this lookup accepts.

Sidetrack and event

The final 4 digits cover directional sidetracks and completion events, which is why the same wellbore can appear under more than one full API number.

For the full segment-by-segment breakdown, including every state code, see the API well number guide. To query the same records programmatically, see Drilling Intelligence.

What this lookup shows, and what it does not

The registry holds one record per well, keyed on its API number. Coverage and update cadence vary by state source, so the honest answer for some fields is that we do not hold them — and this page shows an empty cell rather than an upsell when that is the case.

Free on this page

API well number, formatted and raw
Well name and well number
Operator name
County and state
Permit status and permit date
Total count of matching wells

Included with Drilling Intelligence

Surface coordinates, where the state source publishes them
Legal location — township and range
Results beyond the 5 a free search returns
Recency-sorted queries and bulk export
Aggregation across 27 US states and 3 Canadian provinces
Daily refresh in one schema instead of thirty state websites

Well records originate as public filings with state oil and gas commissions. This service provides aggregation, normalisation, daily refresh and a single format.

Frequently asked questions

What is an API well number?: An API well number is the unique identifier assigned to every oil and gas well drilled in the United States, issued under the American Petroleum Institute numbering standard. The full standardised form is 14 digits: a 2-digit state code, a 3-digit county code, a 5-digit unique well number, a 2-digit directional sidetrack code and a 2-digit event code.
How do I look up a well by its API number?: Type the API number into the search box above. Dashes are optional. You need at least the first 10 digits — shorter prefixes are rejected because a partial county prefix would match thousands of unrelated wells.
Can I search for wells by operator name?: Yes. Enter an operator name such as ROCKIES RESOURCES, or a well name, and the lookup will return matching wells. Name searches need at least 3 characters. You can narrow the results with an optional 2-letter state code.
Is this well API number search free?: Yes. The lookup requires no account and no API key. A free search returns up to 5 wells, alongside the total number of wells that matched, and results are not sorted by recency.
Why are coordinates and legal location hidden?: Surface coordinates and legal location (township and range) are included with Drilling Intelligence access. Where the lookup shows a dash instead of a locked badge, we simply do not hold that field for that well — not every state regulator publishes it.
Where does this well data come from?: State oil and gas commission permit filings, which are public records at the source. What this service adds is aggregation across 27 US states and 3 Canadian provinces, daily refresh, and a single schema in place of thirty separate state websites.
Does one row mean one permit?: No. The registry holds one record per well, keyed on its API number — 2,292,533 records against 2,292,533 distinct API numbers. It is not a permit-event history, so repeat filings on the same well are not represented as separate rows.