What a difference a year makes in shale gas drilling. NGI‘s Shale Daily Unconventional Rig Count dramatically demonstrates the ascendance of oil and oily gas shale plays as the Bakken Shale/Sanish/Three Forks claimed the top spot on the chart for the greatest number of active rigs with 170, up from 102 and third place a year ago.

Eagle Ford, which was number five a year ago with 78 active rigs, sat firmly in the second slot for the week ending March 25 with 158 active oil and gas rigs operating.

The Marcellus, with a varying degree of liquids, demonstrated the importance of location, location, location, coming in No. 3 last week with 143 active rigs, compared to 121 rigs and the No. 2 spot a year ago. Drilling to hold leases also was a factor in the strong showing by the Marcellus. The play’s gain of 18% in number of rigs from a year ago, however, didn’t come close to the 103% growth shown by the Eagle Ford, and the 67% growth in Bakken rigs.

The Haynesville/Bossier slipped dramatically, from 199 rigs a year ago to 139 last week, and from No. 1 to No. 4. The Barnett also lost ground, dropping 19% from 86 rigs and the No. 4 position a year ago to 70 rigs and the No. 6 slot last week. Also in the minus column were the Arkoma-Woodford, the Fayetteville and Green River Basin.

On the lower end of the scale, the Niobrara and Denver-Julesburg Basin went from two rigs to eight rigs.

As for week-over-week, natural gas price bulls received some support for their case from the fresh data, which revealed that drilling activity in the shale plays backed off from the previous week. Rigs operating in North American shale and unconventional plays for the week ending March 25 declined by 11 from the previous week to 972. The largest drop-off was seen in the Eagle Ford, which declined by five rigs to 158. The next largest drop was recorded by the Haynesville/Bossier, which dropped by four rigs to 139.

NGI‘s Shale Daily utilizes county-level rig data provided by Schlumberger’s Smith Bits to more accurately target drilling levels in individual shale plays.