The U.S. onshore well count rose 5% in the fourth quarter from a year earlier, with an average drilling rig completing 9% more wells over the same period, Baker Hughes Inc. reported Friday.

The Houston-based oilfield services operator said the domestic onshore well count in 4Q2013 was 9,056 wells, 19 fewer than in 3Q2013 when there were 9,075 wells.

Compared with 4Q2012, the well count rose by 398 wells, or 5%. In addition, "improved drilling efficiencies" allowed rigs to drill more wells year/year.

The Eagle Ford Shale well count "increased most notably" in the final three months of 2013, gaining 75 wells, or 7% more than a year earlier. The Mississippian Lime well count rose by 23, or 6%, while in the Marcellus Shale, there were 21 more wells (4%) than a year ago.

The increases were offset by a decline in the well count in the Fayetteville Shale, which was down 29 wells or 18%, and the Granite Wash formation, which had 22 fewer wells, or 13% fewer.

The average U.S. onshore rig count in 4Q2013 was down 12 rigs from 3Q2013 at 1,697 rigs, according to Baker.

"On average, the U.S. onshore rig fleet produced 5.34 new wells per day during the fourth quarter, representing a 1% improvement in drilling efficiencies compared to the third quarter," officials said.

The Baker Hughes well count is an extension of the company's rig count, which has provided key activity data for more than 70 years. Baker instituted the dual count system in October (see Shale Daily, Oct. 14, 2013). The U.S. Energy Information Administration last year launched a drilling productivity report to better correlate well numbers with rigs (see Shale Daily, Oct. 22, 2013). Raymond James & Associates Inc. also launched a well count index (see Shale Daily, Sept. 25, 2013).