The U.S. Energy Information Administration’s (EIA) monthly drilling productivity report (DPR) released Sept. 12 now includes a supplement that provides monthly estimates of the number of drilled but uncompleted (DUC) wells in the seven key oil and natural gas producing regions covered by the DPR.

Current EIA estimates show DUC counts at the end of August totaling 4,117 in the four oil-dominant regions and 914 in the three gas-dominant regions that together account for nearly all U.S. tight oil and shale gas production. In the oil regions, the estimated DUC count increased during 2014-2015, but declined by about 400 over the last five months. The DUC count in the gas regions has generally been in decline since December 2013.

Completions have declined even further than drilling in the four DPR regions--the Bakken Shale, the Niobrara, the Permian Basin and the Eagle Ford Shale–that account for nearly all tight oil production, resulting in a growing inventory of DUCs.

Factors contributing to the differential reduction in drilling and completion rates in these regions could include long-term contracts for drilling rigs and lease contracts that mandate drilling and/or production in order to fulfill commitments made to the landowners and mineral-rights owners.

The situation appears to be somewhat different in the other three DPR regions--the Marcellus, the Utica and the Haynesville Shale--where the production mix skews heavily towards natural gas, in which significant price declines began as early as 2012.