here is the EIA statement regarding their estimation of DUC wells which began in September of 2016:
Starting this month, EIA's Drilling Productivity Report (DPR) includes monthly estimates of the number of drilled but uncompleted wells (DUCs) in the seven DPR regions. Estimates will go through the prior month; the September DPR includes estimates through August.
Current EIA estimates show DUC counts as of the end of August totaling 4,117 in the four oil-dominant regions (Bakken, Eagle Ford, Niobrara, and Permian) and 914 in the three natural gas-dominant regions (Haynesville, Marcellus, and Utica) that together account for nearly all U.S. tight oil and shale gas production. In the oil regions, the estimated DUC count increased during 2014 and 2015, but the count declined by about 400 over the past five months. The DUC count in the gas regions has generally declined since December 2013.
DUCs are wells that have been drilled by producers, but have not yet been made ready for production. The full completion process involves casing, cementing, perforating, hydraulic fracturing, and other procedures to make the well ready to begin producing oil or natural gas. Following the large decline in oil prices since mid-2014, new drilling and completion activity slowed, and the number of DUCs in oil-dominant regions increased. A high inventory of DUCs has implications for the size and timing of the domestic supply response to changes in oil prices, with or without significant changes in the number of active drilling rigs.
Although both drilling and completion activity have declined since late 2014, the completions have experienced a deeper decline than drilling in oil-dominant regions. The differences in drilling and completion rates in these oil regions may be attributed to several factors. For instance, some long-term contracts for drilling rigs and lease contracts may mandate drilling or producing in order to fulfill commitments made to the landowners and mineral-right owners.
Estimates of the number of DUCs have been available from other sources. These estimates often vary significantly because of differences in methodology and operational assumptions, or, in some cases, insufficient data. EIA develops its estimates of DUCs for all seven regions in the Drilling Productivity Report using a consistent methodology and uniform assumptions.
I think the important point is these are all "estimates" reason being that the EIA has no idea of what the actual intention of a company might be going forward. All they know is that the well was drilled and then suspended awaiting completion. In my experience there are a host of reasons why you would suspend a well and not plug and abandon it. One important one is trying to time write downs around other company financial burdens if you are a public company, another might be trying to postpone all abandonments so that you could do a number of them back to back (considerable cost savings). It is doubtful that all of the wellls listed as DUC will ever be completed, nor is there any guaranty of whether a frack will result in sustained economic production rates. That being said it is a useful estimate if you keep in mind all the uncertainty in the data.
