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.

Wildcatters EditorialUpdated 5 min read

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.
  1. 01 →

    Permit

    Permission for the proposed work

  2. 02 →

    Spud

    Drilling operations begin

  3. 03 →

    Drilling

    The wellbore is constructed

  4. 04 →

    Completion

    Work to prepare the well for production

  5. 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 indicateIt does not establish
Drilling has occurred and completion remains outstanding under the source’s definitionA promised completion or first-production date
A point in the reported development sequenceA producing well or a revenue stream
An observation at a particular reporting dateThe current field condition after that date
Part of an aggregate inventoryA 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

  1. Match the well. Record the state, name, operator, and official identifier.
  2. Check the dates. Distinguish the spud date, drilling completion, completion work, and the date a record was filed or retrieved.
  3. 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.
  4. Keep production periods attached. A historical reported volume is not a live field reading.
  5. 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 well

Sources and review

Primary sources are linked beside the relevant explanations. Updated 2026-09-11; source publication dates and jurisdictions still apply.