Wildcatters Learn · Well research
What is a drilled but uncompleted well?
A drilled but uncompleted well, or DUC, has been drilled but has not completed the work needed to begin production. DUC status does not establish a production start date; completion timing can vary substantially.
What to know
- Drilling and completion are different stages.
- DUC status does not guarantee future output or timing.
- An aggregate inventory is not a status report for your well.
- 01 →
Permit
Permission for the proposed work
- 02 →
Spud
Drilling operations begin
- 03 →
Drilling
The wellbore is constructed
- 04 →
Completion
Work to prepare the well for production
- 05
Production
Oil or gas is produced and reported
Drilling creates the wellbore; completion prepares it
Drilling constructs the wellbore. Completion involves the work and equipment needed to prepare it for production. The EIA completion glossary provides terminology for this stage.
The required work depends on the well and reservoir. Do not assume that every DUC is a horizontal shale well or requires the same fracturing program. A spud date marks the start of drilling; it is not the date drilling or completion finished.
Why completion can be delayed
Drilling and completion can use different crews, equipment, and schedules. Operators may sequence work across multiple wells or postpone a completion for operational or economic reasons.
EIA’s 2019 North Dakota analysis documents completion delays and discusses scheduling flexibility and economic conditions. Its historical observations do not establish the timing or economics of a particular well today. The reason for an individual delay should come from that well’s records or the operator, not from the DUC label alone.
What DUC status does and does not establish
| A DUC description can indicate | It does not establish |
|---|---|
| Drilling has occurred and completion remains outstanding under the source’s definition | A promised completion or first-production date |
| A point in the reported development sequence | A producing well or a revenue stream |
| An observation at a particular reporting date | The current field condition after that date |
| Part of an aggregate inventory | A guaranteed amount of future supply or demand for drilling rigs |
An inventory count must be interpreted using its coverage, definitions, and observation period. Do not infer one property’s completion status from a basin total.
How to research the underlying well
- Match the well. Record the state, name, operator, and official identifier.
- Check the dates. Distinguish the spud date, drilling completion, completion work, and the date a record was filed or retrieved.
- Read the available filings. Look for completion reports and subsequent production records. The RRC research queries provide Texas permit, completion, and other research entry points.
- Keep production periods attached. A historical reported volume is not a live field reading.
- Record uncertainty. Missing or delayed filings do not prove that no work has occurred.
Use Intelligence 2.0 to start with a connected jurisdiction. Where coverage does not support the required record, use the regulator’s source and state what remains unverified.
Questions about a well that remains uncompleted
Will every DUC eventually produce?
The label does not guarantee that a well will be completed or produce commercially. It describes a development status, not a commitment or performance forecast.
Does completion mean the first royalty payment is due?
Completion, reported production, sales, and owner payments are different events. Payment questions also depend on the relevant ownership and payment documents.
Can a DUC count predict new production next month?
A count by itself does not supply a completion schedule or expected production rate for each well. Additional evidence is needed before making a forecast.
Put it into practice
Find the next record in the well’s history
Check completion and production reporting for the well, keeping the source and observation dates together.
Research a wellRelated reading and research
Sources and review
Primary sources are linked beside the relevant explanations. Updated 2026-09-11; source publication dates and jurisdictions still apply.