By OGJ editors
HOUSTON, Feb. 25 -- Interpretation of microseismic data from one 18-sq-mile area appear to support the drilling of eight Bakken and Three Forks wells per 1,280-acre spacing unit in the Williston basin, said Brigham Exploration Co., Austin.
The company will ramp gradually to 12 operated rigs by September 2012 after adding its eighth rig this May and is beginning to use smart pad development in its Ross and Rough Rider areas in North Dakota.
Brigham hiked proved reserves 141% to 66.8 million boe, 78% oil, in 2010, by drilling 44 net wells, 39 of them in the Williston basin. An 800,000 boe downward revision involved conventional gas reserves unlikely to be drilled within 5 years.
Microseismic data accumulated during the Brad Olson 9-16 2H well fracture stimulation indicates that frac wings appear to extend laterally 500 ft on either side of the wellbore. The results imply an increase to 782 total net locations from 590 in the Ross-Parshall-Austin and Rough Rider project areas, Brigham said.
Meanwhile, the company’s second Montana Bakken completion, Swindle 16-9 1H, produced at an early 24-hr peak flow back rate of 1,065 b/d of oil equivalent. Two recent North Dakota Bakken completions averaged 3,513 boe/d.
Brigham anticipates drilling 66 net Bakken and Three Forks wells in 2011 compared with 39 net wells in 2010. Drilling capital is estimated at $582.1 million or $7.9 million/well, which includes a 10% budgeted overage.
Smart pad development can be implemented either by drilling multiple wells from the same location in a single spacing unit or by drilling stacked 1,280-acre spacing units, one to the north and one to the south, and drilling multiple wells in both spacing units from the same location. When fully implemented it is likely to save 10-20%/well, Brigham said.
Drilling efficiencies are achieved by minimizing rig moves and the laying down of drill pipe and changing of mud systems. Completion efficiencies are achieved via the simultaneous fracture stimulation of adjacent wells. Initial results indicate that 9-11 stages a day can be performed compared with 6 stages a day at individual wells.
Brigham estimates that 112 of its 188 operated 1,280-acre spacing units in Rough Rider and Ross are adjacent units that provide additional drilling and completion efficiencies, 26 of which are to be drilled in 2011.
The Swindle 16-9 1H, in Roosevelt County, Mont., was completed with 19 frac stages because the liner with swell packers didn’t reach total depth. About 3,200 ft of the outermost wellbore was completed with a single open hole frac stimulation.
In Richland County, Mont., Brigham is stimulating the Johnson 30-19 1H with 30 stages after successfully running liner to bottom and is recompleting the Voss 21-11H, purchased from another operator that drilled and completed it in August 2007 with a single frac stimulation. Brigham plans 28 stages after running a liner with swell packers.
Brigham has completed 51 consecutive long lateral, high frac stage wells in North Dakota with an average early 24-hr peak flow back rate of 2,858 boe/d.
A minimum of 8 wells/month are to be brought on production starting in mid-April, when two fully dedicated frac crews will be at work.