The Cana-Woodford, Eagle Ford and Bakken/Sanish/Three Forks plays continued to lead the activity growth in unconventional fields over the last year as oil and gas producers put more weight on liquids-rich shales to take advantage of higher commodity prices found in oil and natural gas liquids. Conversely, some of the nation’s dry gas shales have seen the largest drilling activity declines as natural gas prices remain below $4/MMBtu for much of the country.

According to NGI‘s Shale Daily Unconventional Rig Count for the week ending Sept. 30, the Cana-Woodford and Eagle Ford shales have both enjoyed 61% increases in drilling activity since last year, with Cana-Woodford going from 41 to 66 rigs and the Eagle Ford increasing from 129 to 208.

The next two largest increases from a year ago were found in the Bakken/Sanish/Three Forks and Uinta Basin, which saw 34% and 31% jumps from 143 to 192 rigs and from 16 to 21 rigs, respectively.

The top four growth plays share one common denominator. The Cana-Woodford of Western Oklahoma, the Eagle Ford of South and East Texas, the Bakken/Sanish/Three Forks of Canada, North Dakota and Montana and the Uinta Basin of eastern Utah and western Colorado are oil-rich shales.

The three plays that showed the largest activity drops over the last year are the Arkoma-Woodford in southeastern Oklahoma, the Barnett of North Texas and the Haynesville/Bossier of Northwest Louisiana, East Texas and a little bit of Arkansas, which are predominantly dry gas plays. Arkoma-Woodford is down 38% from 26 to 16 rigs, while the Barnett is down 37% from 89 to 56 rigs, and the Haynesville/Bossier is down 34% from 163 to 108 rigs.

NGI‘s Shale Daily Unconventional Rig Count utilizes county-level rig data provided by Smith Bits, a Schlumberger company, to more accurately target drilling levels in individual shale plays (see