As many as four dolomite benches in the Three Forks formation that underlies the Bakken in the Williston basin may have oil potential, said Continental Resources Inc., Enid, Okla.
Continental in 2011 cut six cores of the entire vertical thickness of the Three Forks formation, which is 180-270 ft thick under its acreage, over a distance of 115 miles north to south. The cores revealed that the formation has up to four separate benches of dolomite that contain oil.
Continental initially targeted the first bench of Three Forks, about 20 ft below the Lower Bakken shale, in mid-2008 (OGJ Online, July 10, 2008).
In October Continental’s Charlotte 2-22H well in McKenzie County, ND, made 1,140 b/d of oil equivalent on its first 24-hr test as the company’s first horizontal test of a deeper Three Forks bench. The well’s lateral taps the second bench 50 ft below a typical first-bench lateral.
The Charlotte well test “demonstrates that the Three Forks second bench has the potential to add incremental reserves to our estimated 24 billion boe of technically recoverable oil and natural gas in the total Bakken,” Continental said.
Continental has set a 2012 capital budget at $1.75 billion, less than planned 2011 spending, “reflecting a slightly lower growth rate next year as North Dakota builds infrastructure to cope with the demands of accelerated drilling in the Bakken play since mid-2009.”
Continental said its rate of return in the Bakken is 40-50% based on $8 million/well and estimated ultimate recovery of 603,000 boe/well.
The company holds 901,098 net acres in the Bakken, 72% of it in North Dakota and 68% of it undeveloped. It is running 23 operated rigs, including two in Montana, and has 45 wells in completion stages.