Daily drilling reports · rig time

IADC daily drilling report codes, explained

IADC daily drilling report (DDR) codes are the standard numbers drilling crews use to classify every hour of rig time on the IADC daily report, or tour sheet. Code 2 is drilling, 6 is trips, 8 is rig repair, 12 is running casing and cementing, 19 is fishing, and so on. Since 2019 the IADC DDR Plus has 34 main codes: it keeps the 23 operational codes of the paper report, with minor clarifications, adds new ones such as operating status, safety and well control, and lets each code be broken down further into activity and equipment sub-codes. Because each code has defined start and stop points, the same 24 hours can be compared across rigs, wells and contractors, which is what makes lost time and nonproductive time measurable. These are not the same as IADC bit codes, which classify drill bits.

Reference summary only. The definitions below paraphrase IADC's published DDR Plus code definitions; use the current IADC documents and your contract's reporting requirements for the exact wording, sub-codes and rules.

1. What the IADC daily drilling report is

The IADC daily drilling report, often called the tour sheet, is the standard daily record of a drilling rig's work. It records the crew, depths, the bit and bottom-hole assembly, mud properties, pumps, casing, safety events and, above all, a time log: every period of the day, its start and end time, its code and a short description of what was done. Drilling contracts commonly use it as the basis for agreeing what happened on the rig and how the time is paid, so the time codes matter to the contractor, the operator and the accounts team, not only the driller.

IADC introduced the DDR Plus in March 2019. It kept the legacy operational codes with minor clarifying changes and added new top-level codes, giving 34 main codes. Each main code can cascade into an activity, an activity sub-code, an equipment code and an equipment sub-code, so a report can say not just "rig repair" but which piece of equipment failed. IADC also published an electronic schema for the report, based on the Energistics WITSML data-transfer standard, so reports can move between systems without retyping.

2. The main IADC DDR Plus codes

The table summarises the main codes and their start and stop points, paraphrased from IADC's DDR Plus definitions document.

Code	Operation	What it covers and when it starts and stops
1	Rig up / tear down / rig move	From the first rig components arriving on site until the rig is ready to spud; tear down runs until the last component has left. Offshore rig moves are included.
2	Drilling	Making new hole. Starts when boring begins and ends when it stops. Also used for drilling out shoe tracks and dressing off cement plugs.
3	Reaming	Smoothing or enlarging the hole, straightening doglegs or helping directional work; from the start to the end of rotating and circulating for that purpose.
4	Coring	Cutting a cylindrical rock sample for geological analysis.
5	Circulate & condition mud	Adjusting mud properties such as weight and viscosity and circulating; from blending additives until circulation is complete and the pumps are off.
6	Trips	Running or pulling the BHA to or from a depth, including wiper and check trips to test hole condition, tight spots or mud weight.
7	Service / maintain rig	Planned maintenance, whether time-, condition- or usage-based; from taking the equipment off line until it is back in service.
8	Repair rig	Reactive repair of unexpected equipment failure that stops operations; from the failure until the equipment is back in service.
9	Replacing drill line	Slipping and cutting or replacing drilling line, from removing the drawworks from service until it is returned. See ton-mile calculation.
10	Deviation survey	Measuring borehole trajectory on the critical path.
11	Wireline logs	From assembling and running the logging tools until they are fully retrieved.
12	Run casing & cement	From rigging up casing equipment until the last of the cement is in place.
13	Wait on cement	From shutting down the cement pumps until tests show the cement has hardened enough.
14	Rig up / down BOP	Assembling a surface (dry) BOP stack until it is installed and ready to use or test.
15	Test BOP	From the start of function and pressure testing until all measurements are made and approved.
16	Drill stem test	From picking up the test packers until all tools are out of the hole.
17	Plug back	From running the plug or cement head until the tools are back at surface.
18	Squeeze cement	From rigging up squeeze equipment until it is rigged down.
19	Fishing	From picking up the fishing assembly until it is back at surface.
20	Specialised directional work	Work with a directional assembly when deviating from the primary wellbore; otherwise directional drilling falls under code 2 sub-codes.
21–23	Other	User-defined operations not covered by another code.
31	Run / retrieve riser equipment	Offshore: moving the BOP and marine riser to and from well centre.
32	Surface testing	Testing well-related surface equipment, such as the choke or standpipe manifold, while it holds up other work.
33	Operating status	Periods when the rig is not performing well operations, such as standby, from one change of status to the next.
34	Safety	Safety meetings, training, stand-downs, job safety analyses and drills.
35	Well control	Actions taken to return the well to a safe state after a loss of hydrostatic control. See kill sheet calculations.
36	Coiled tubing	From running the coiled tubing in the hole until it is fully retrieved.
37	Completion activities	Perforating, tubing trips, treating, swabbing and testing.
38	Subsea installations	Subsea work, which varies by situation.

Codes 21 to 23 are deliberately open, so a contractor or operator can define its own categories for work that has no standard code. Agree what they mean at the start of the contract, otherwise "Other" becomes the place where unexplained hours collect.

3. Why start and stop rules matter

The value of the codes is that everyone draws the line in the same place. A trip under code 6 starts when the crew picks up or starts pulling the BHA and ends when it reaches the target depth or is laid down. Waiting on cement under code 13 starts when the cement pumps stop, not when the cement job was planned to finish. Rig repair under code 8 starts at the moment of failure. With defined start and stop points, the hours for each activity can be totalled and compared between rigs, wells and contractors: how long trips take per thousand feet, how much time goes to BOP testing, or how many hours a month are lost to repairs.

4. Productive time, lost time and NPT

The codes do not, on their own, say whether time was productive. That depends on whether the work was planned. Drilling, planned trips, casing and cementing, logging and BOP tests are normally part of the well plan. Time spent dealing with something that went wrong is usually counted as nonproductive time (NPT). Typical examples:

Rig repair (code 8): unplanned equipment failure. Planned maintenance under code 7 is not the same thing.
Fishing (code 19): recovering a lost or stuck part of the string.
Well control (code 35): regaining control after a kick.
Unplanned trips and reaming: for example a trip to replace a failed downhole tool, or reaming through a tight spot caused by hole problems.
Waiting: on equipment, materials, weather, orders or third-party services, often recorded with the operating status or a user-defined code.

DDR Plus added a dedicated nonproductive-time category and equipment sub-codes so the cause can be recorded at source. Whatever system a company uses, the rule is the same: log NPT with a cause, the equipment involved and who was responsible, at the time it happens, so that it can be analysed later and, where the contract says so, charged at the right rate.

There is also time that never shows up as NPT because the operation was planned: a trip that took twice as long as it should have, or slow connections. That is often called invisible lost time, and it can only be found by comparing coded durations against a benchmark, such as the same operation on previous wells. For NPT formulas, a worked example and ways to reduce it, see NPT in drilling, explained.

5. Common daily drilling report errors

Hours that do not add up to 24. Gaps and overlaps in the time log are the most common error. Every period of the day needs a code, including standby and waiting.
Depth that goes backwards. Measured depth at the end of the day shallower than at the start, without a plug-back or sidetrack to explain it.
Footage without drilling time. New hole reported with no hours under code 2, or drilling hours with no footage.
Everything under "Other". User-defined codes used as a catch-all, which hides where time went.
Repair logged as maintenance. Reactive repairs booked under code 7 make the rig look more reliable than it is and understate NPT.
No cause on lost time. An NPT entry that says only "waiting" or "repair" cannot be analysed or fixed.

6. In DrillX

DrillX daily drilling reports use IADC-style time logs. DrillX checks each report as you type, flags lost time and catches errors such as depth at 24:00 shallower than at 00:00, or footage with no drilling time logged. The rig fleet view shows each rig's latest position from its daily report, and NPT insights show where rig time is being lost. DrillX also includes calculators such as a kill sheet, ECD and string volumes. DrillX opens soon; email info@drillx.app for a demo or early access.

Questions

What are IADC DDR codes?

IADC DDR codes are the standard time codes on the International Association of Drilling Contractors' daily drilling report. Each hour of rig time is logged against a numbered code, such as 2 for drilling, 6 for trips or 8 for rig repair, so that rig time can be totalled and compared in a consistent way across rigs, wells and contractors.

How many codes are in the IADC DDR Plus?

The IADC DDR Plus, launched in March 2019, has 34 main codes. It keeps the 23 legacy operational codes with minor clarifying changes, adds new codes including operating status, safety, well control, coiled tubing and subsea installations, and breaks each code down into activity and equipment sub-codes.

What is the difference between code 7 and code 8 on the IADC report?

Code 7, service and maintain rig, is planned maintenance done to keep equipment working. Code 8, repair rig, is reactive: it starts when equipment fails unexpectedly and ends when it is back in service, and it normally sits on the critical path, so it is usually counted as lost or nonproductive time.

Are IADC DDR codes the same as IADC bit codes?

No. IADC bit classification codes describe drill bits, for example a three-digit code for roller-cone bits by formation hardness and bearing type, and IADC dull grading describes bit wear. DDR codes classify rig time on the daily drilling report.

How is nonproductive time recorded on the IADC report?

Time spent on unplanned events, such as rig repair, fishing for lost equipment or regaining well control, is logged under the matching code and usually flagged as nonproductive. IADC's DDR Plus also added a dedicated nonproductive-time category and sub-codes for the activity and equipment involved, so the cause can be analysed later.

Do the hours on an IADC daily report have to add up to 24?

Yes. A daily report covers the full day, so the time log for each 24-hour period should total exactly 24 hours, including waiting, standby and other non-drilling time. Gaps or overlaps are one of the most common reporting errors.

Sources and further reading

IADC, Definitions of the 34 Main Codes of the IADC DDR Plus (2019).
Drilling Contractor, IADC launches DDR Plus to enable more granular data collection (March 2019).
IADC Drilling Manual (International Association of Drilling Contractors): daily reporting and rig operations.