National Oil
Operator of record for 79 catalogued wells across 9 states. Every well below links to its full registry page.
Filed as: NATIONAL OIL CO · NATIONAL OIL CO. · NATIONAL OIL COMPANY · National Oil Co. · …
At a glance
National Oil is the operator of record for 79 catalogued U.S. oil & gas wells in 9 states. 1 (1%) are active, 42 (53%) plugged & abandoned and 23 flagged as orphaned. Its largest concentration is in Kansas, with 24 wells (30% of its portfolio).
Wells operated
79
Active
1
Plugged
42
Orphaned
23
Portfolio by state
| State | Wells |
|---|---|
| Kansas | 24 |
| California | 23 |
| Colorado | 11 |
| Wyoming | 11 |
| North Dakota | 4 |
| Illinois | 2 |
| Louisiana | 2 |
| Montana | 1 |
| Utah | 1 |
Well mix
- Oil wells
- 44
- Gas wells
- 4
- Shut-in
- 0
- Active share
- 1%
Is this your company?
Claim National Oil to keep this portfolio accurate — verified operators can correct well statuses and add plugging documentation.
Claim your operator profileWhere does National Oil operate?
National Oil's catalogued wells are spread across 9 states: Kansas (24), California (23), Colorado (11), Wyoming (11) and North Dakota (4) and 4 more. Its 23 California wells are 0.0% of the 242,471 catalogued in that state — its largest share of any state. Counts cover only states whose registries WellCensus has ingested with operator names; wells in Nebraska and Texas (location indexes) and in states without a registry ingest are not yet attributed to any operator.
How many of National Oil’s wells are active, plugged or orphaned?
1% of National Oil's catalogued wells are active, 28 percentage points below the national share of 29%. 53% are plugged & abandoned, against 47% nationally. 23 wells filed under this name are flagged as orphaned — unplugged, with no operator able to plug them.
What kinds of wells does National Oil operate?
By product class, 44 (56%) are oil wells and 4 (5%) gas wells; nationally the shares are 43% and 17%. The deepest of its wells with a published depth is Federal 23-5 in Campbell, WY at 10,344 ft. The wells listed below sit in Campbell (WY), Bowman (ND), Williams (ND), Moffat (CO), Musselshell (MT) and Crook (WY). State filings spell the name 5 ways; WellCensus merges exact-normalized spellings only, so subsidiaries and affiliates keep their own pages.
Notable wells operated by National Oil
| Well | API # / state ID | Status | Type | Location | Operator | Depth |
|---|---|---|---|---|---|---|
| Federal 23-5 | 49-005-26232 | Other status | Oil | Campbell, WY | National Oil Company | 10,344 ft |
| Steinhoefel Fee 23-7 | 49-005-26915 | Plugged & abandoned | Oil | Campbell, WY | National Oil Company | 10,200 ft |
| Steinhoefel 41-1 | 49-005-26914 | Plugged & abandoned | Oil | Campbell, WY | National Oil Company | 10,200 ft |
| Shippey Superior Fee 1-33 | 49-005-25668 | Plugged & abandoned | Oil | Campbell, WY | National Oil Company | 9,700 ft |
| G. Ehrmantrout 21-25 | 33-011-00390 | Plugged & abandoned | Oil | Bowman, ND | National Oil Co. | 9,682 ft |
| Hought 43-2 | 33-105-01056 | Plugged & abandoned | Oil | Williams, ND | National Oil Co. | 9,100 ft |
| 1(D) Helmke-Federal | 05-081-05296 | Plugged & abandoned | Other type | Moffat, CO | National Oil Co | 8,318 ft |
| Fee 32-12 | 49-005-25699 | Plugged & abandoned | Oil | Campbell, WY | National Oil Company | 7,700 ft |
| Zimmerman 1-20 | 25-065-21638 | Plugged & abandoned | Other type | Musselshell, MT | National Oil Company | 7,501 ft |
| Diamond Shamrock 33-23 | 49-005-25959 | Plugged & abandoned | Oil | Campbell, WY | National Oil Company | 7,480 ft |
| #42-18 Helmke-Federal | 05-081-06580 | Plugged & abandoned | Other type | Moffat, CO | National Oil Co | 7,365 ft |
| Chorney W-55039 31-18 | 49-011-20850 | Plugged & abandoned | Oil | Crook, WY | National Oil Company | 7,300 ft |
Deepest first where depth is published. See all 79 wells →
Frequently asked questions
How many wells does National Oil operate?
National Oil is the operator of record for 79 catalogued oil & gas wells, with the largest concentration in Kansas (24). Only wells in states WellCensus has ingested are counted.
How many of National Oil's wells are still active?
1 of National Oil's catalogued wells are active; 42 are plugged & abandoned and 23 are flagged as orphaned.
In which states does National Oil operate wells?
National Oil is the operator of record for wells in Kansas (24), California (23), Colorado (11), Wyoming (11), North Dakota (4), Illinois (2), Louisiana (2), Montana (1) and Utah (1).
Does National Oil operate mostly oil or gas wells?
44 of National Oil's catalogued wells are oil wells and 4 are gas wells; the rest are injection, service or unclassified wells.
What is National Oil's deepest well?
Among wells with a published depth, Federal 23-5 in Campbell, WY is the deepest at 10,344 ft.
Where National Oil's wells are
- Oil & gas wells in Kansas· 24 operated by National Oil
- Oil & gas wells in California· 23 operated by National Oil
- Oil & gas wells in Colorado· 11 operated by National Oil
- Oil & gas wells in Wyoming· 11 operated by National Oil
- Oil & gas wells in North Dakota· 4 operated by National Oil
- Oil & gas wells in Illinois· 2 operated by National Oil
- Largest U.S. well operators
- All well operators
About this data
Source: State oil & gas regulator registries (operator of record as filed, exact-normalized across states) plus the USGS United States Documented Orphaned Well Database (2026), as published October 10, 2026 — WellCensus refreshes it monthly. See the methodology for how records are matched, cleaned and scored.
Cite as: WellCensus, “National Oil — well portfolio”, https://wellcensus.com/operators/national-oil-7189 (data as of October 10, 2026).
Dataset updated . Operator portfolios are resolved from raw state registry filings (exact-normalized names; subsidiaries stay separate).